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Aims Real-world data on treatment persistence, safety and effectiveness of non-Vitamin K antagonist oral anticoagulants (NOACs) play an important role in the assessment of risks and benefits of these drugs. Our aim was to evaluate persistence on treatment, incidence of major bleeding and incidence of a composite endpoint of major events, including all-cause death, myocardial infarction, stroke and systemic thromboembolism, during treatment with apixaban in a cohort of patients with nonvalvular atrial fibrillation (NVAF). Methods In this multicentre retrospective observational study, we retrieved data from medical records of five Italian hospitals on patients with a diagnosis of NVAF who initiated apixaban between 1 January 2014 and 31 March 2016 and had a first subsequent visit at the same hospital. Results We studied 766 patients with mean age of 74.2 (standard deviation 11.1) years and median CHADS2 and CHA2DS2VASc scores of 2.0 and 4.0, respectively. Over a median follow-up period of 339 days, persistence on treatment was 83.5% [95% confidence interval (95% CI) 75.5-89.1%]. The rate of major bleeding (per 100 person-years) was 1.15 (95% CI 0.39-1.90 per 100 person-years), while the cumulative incidence was 4.4% (95% CI 1.6-12.0). The rate of major events was 1.97 (95% CI 1.08-2.86) per 100 patient-years, with a cumulative incidence over the entire follow-up period of 7.7% (95% CI 4.6-12.8). Conclusion In real-life conditions, NVAF patients treated with apixaban show rates of treatment discontinuation and major bleedings, which are comparable to those found in the ARISTOTLE pivotal study, thus supporting its external validity.

Oral bosentan is an established treatment for pulmonary arterial hypertension (PAH).To evaluate safety, tolerability, and clinical and haemodynamic effects of bosentan in patients with PAH related to congenital heart disease (CHD).22 patients with CHD related PAH (8 men, 14 women, mean (SD) age 38 (10) years) were treated with oral bosentan (62.5 mg x 2/day for the first 4 weeks and then 125 mg x 2/day).Clinical status, liver enzymes, World Health Organisation (WHO) functional class, resting oxygen saturations and 6-min walk test (6MWT) were assessed at baseline and at 1, 3, 6, and 12 months. Haemodynamic evaluation with cardiac catheterisation was performed at baseline and at 12 month follow-up.12 patients had ventricular septal defect, 5 atrioventricular canal, 4 single ventricle, and 1 atrial septal defect. All patients tolerated bosentan well. No major side effects were seen. After a year of treatment, an improvement was seen in WHO functional class (2.5 (0.7) v 3.1 (0.7); p0.05), oxygen saturation at rest (87 (6%) v 81 (9); p0.001), heart rate at rest (81 (10) v 87 (14) bpm; p0.05), distance travelled in the 6MWT (394 (73) v 320 (108) m; p0.001), oxygen saturation at the end of the 6MWT (71 (14) v 63 (17%); p0.05), Borg index (5.3 (1.8) v 6.5 (1.3); p0.001), pulmonary vascular resistances index (14 (9) v 22 (12) WU m(2); p0.001), systemic vascular resistances index (23 (11) v 27 (10) WU.m(2); p0.01), pulmonary vascular resistances index/systemic vascular resistances index (0.6 (0.5) v 0.9 (0.6); p0.05); pulmonary (4.0 (1.3) v 2.8 (0.9) l/min/m2; p0.001) and systemic cardiac output (4.2 (1.4) v 3.4 (1.1) l/min/m2; p0.05).Bosentan was safe and well tolerated in adults with CHD related PAH during 12 months of treatment. Clinical status, exercise tolerance, and pulmonary haemodynamics improved considerably.

1 The interactions between dihydropyridine Ca2+ channels and endothelin were analysed using combined radioligand binding and autoradiographic techniques. 2 Endothelin is a potent constrictor peptide of arterial smooth muscle. Endothelin-induced vasoconstriction is attenuated by dihydropyridine-type Ca2+ antagonists such as nicardipine. However, the molecular mechanisms of this effect are not yet understood. 3 Sections of the human renal artery bound [3H]-nicardipine in a manner consistent with the labelling of dihydropyridine-type Ca2+ channels. The highest density of [3H]-nicardipine binding sites occurred within the tunica media of the renal artery, probably over smooth muscle. A lower density of [3H]-nicardipine binding sites was noticeable in the tunica adventitia, whereas no specific binding occurred in the tunica intima. 4 Endothelin-1, from a concentration of 1 pm 1−1, reduced [3H]-nicardipine binding as a function of concentration. A 10 nm endothelin concentration reduced [3H]-nicardipine binding by about 85%. The isoform, endothelin-3, had little effect on [3H]-nicardipine binding. 5 The above findings suggest the occurrence of an interaction, probably at the receptor level, between [3H]-nicardipine binding and endothelin-1. This interaction probably accounts for the attenuation of endothelin-1-elicited vasoconstriction induced by nicardipine.

The effect of the Ca2+ channel blocker nicardipine on the circle of Willis and the different sized pial arteries was assessed in 20-week-old spontaneously hypertensive rats (SHR) using quantitative image analysis techniques. Normotensive Wistar Kyoto (WKY) rats were also used as a normotensive reference group. In SHR a significant increase of systolic blood pressure (SBP) is noticeable in comparison with WKY rats. The media-to-lumen ratio was increased in the circle of Willis arteries, large sized (diameterthan 150 microns), medium sized (diameter between 150 and 50 microns) and small sized (diameterthan 50 microns), pial artery branches. An increase in the thickness of the tunica media and a luminal narrowing was also seen in medium and small sized pial arteries of SHR in comparison with WKY rats. Treatment with an oral dose of 10 mg/Kg of nicardipine 3 h before the sacrifice significantly reduced SBP in SHR. The drug was without effect on circle of Willis and on large sized pial arteries. Moreover, treatment with nicardipine reduced the thickness of the tunica media, the media-to-lumen ratio and increased the luminal area in medium and small sized pial artery branches. These findings show that treatment of SHR with nicardipine significantly reduces SBP and causes a moderate vasodilatation of arteries regulating cerebrovascular resistance. This property may be useful in avoiding generalized or exaggerated cerebrovascular dilatation which could be accompanied by impaired brain perfusion in hypertension.

Bosentan, an endothelin (ET) ETA-ETB receptors antagonist, is an effective therapy for idiopathic pulmonary arterial hypertension (PAH) and for PAH related to connective tissue disease (CTD). The aim of this study was to evaluate the behaviour of ET-1 and brain natriuretic peptide (BNP) venous plasma levels during a 6-month dual ET-1 receptor blockade and the potential influence of baseline ET-1 venous plasma levels on the clinical efficacy of bosentan.Twenty-five patients with PAH (idiopathic n=16, CTD n=9) in WHO functional class II-III were included in this study. After initial evaluation, patients' WHO class, 6-minute walking-test (6MWT), ET-1 and BNP venous plasma levels were assessed at baseline and after 6-month bosentan therapy. To evaluate whether the ET-1 levels could influence the clinical response to bosentan, data were analyzed for the whole population which was stratified according to high and low ET-1 plasma levels (on the basis of the baseline median value of ET-1 plasma: Gr.118.7 pg/ml, Gr.218.7 pg/ml).Study population included patients with moderate-severe PAH. After 6-month of treatment we observed a significant increase in 6MWT distance (from 435+/-85) m to 467+/-77 m, p0.001) and an improvement in WHO class (from 2.4+/-0.5 to 2+/-0.6 p0.01), with a significant decrease in BNP (from 87+/-33 pg/ml to 67+/-41 pg/ml, p=0.006) and a trend towards lower ET-1 plasma levels (from 17.7+/-5 pg/ml to 16+/-6 pg/ml, p=ns). Improvement in effort tolerance (Delta distance) was not correlated to modification in ET-1 (DeltaET-1) and BNP (DeltaBNP) plasma levels, while we found a significant correlation between DeltaET-1 and DeltaBNP (r=0.63, p=0.0006). Analyzing the subpopulation, Gr.2 patients were older (Gr.1: 41+/-10 years vs Gr.2: 50+/-9 years, p=0.04), had less effort capacity (6MWT distance, Gr.1: 469+/-76 m, vs Gr.2: 398+/-82 m, p=0.03), and showed a trend towards higher BNP values (Gr.1: 82+/-41 pg/ml vs Gr.2: 92+/-23 pg/ml, p=0.051), but no significant differences in pulmonary hemodynamics. After the 6-month treatment both groups showed a significant improvement in 6MWT (Gr.1: +32+/-24 m, Gr.2: +32+/-21 m p=0.05) without differences between groups. WHO class had a trend towards lower class (Gr.1: -0.5+/-0.5, Gr.2: -0.3+/-0.4 p=0.15) in both groups. BNP plasma levels showed a significant decrease only in Gr.2 (Gr.1: -6+/-41 pg/ml, Gr.2: -34+/-19 pg/ml p=0.02); similarly ET-1 plasma levels showed a trend towards a decrease only in Gr.2 (Gr.1: 0.2+/-4.6 pg/ml, Gr.2: -3.8+/-6.6 pg/ml p=0.09).Our data confirm that bosentan is an effective therapy for patients with PAH. Its clinical efficacy (effort tolerance and NYHA) seems to be independent from baseline venous ET1 plasma levels. Bosentan therapy seems to elicit different patterns in ET-1 and BNP plasma levels, with decrease of the peptides only in patients with higher activation of the systemic endothelin system. Further studies are warranted to explore the potential impact of baseline ET-1 levels on the long-term effects (clinical worsening) of bosentan therapy.

Age-related changes in the density of the noradrenergic perivascular plexus supplying the uterine artery and its intrauterine branches were studied in rats 4, 12 and 24 months old using the glyoxylic acid fluorescence technique. Moreover, uterine noradrenaline levels were determined by means of high pressure liquid chromatography with electrochemical detection. No changes in the density of noradrenergic innervation or in uterine noradrenaline levels were noticeable in 12 month in comparison with 4 month rats. In contrast, a significant decrease in the density of the noradrenergic perivascular plexus of uterine artery and of its intrauterine branches as well as decrease in noradrenaline concentrations of uterine horns and cervix were observed in 24 month rats. The above findings indicate an age-related impairment of uterine noradrenergic innervation.

The age dependent loss of nerve cells was investigated in 22 brain areas from young (3 month), adult (13 month) and old (25 month) Sprague-Dawley rats. As in previous studies, we observed an age-related neuronal loss primarily in the archicortex and in the hippocampus and in other subcortical structures (amigdaloid nucleus, pontine nuclei, cerebellar cortex). In sensory areas of cerebral cortex the neuronal loss was less marked. The effect of a 6 month treatment with acetyl- l -carnitine (ALCAR) on the number of nerve cells in the same brain areas was also investigated. ALCAR treatment began when the rats were aged 16 months. ALCAR treatment was able to counteract the age-dependent decrease in nerve cell number primarily in the temporal and occipital cortical areas, in the archicortex and hippocampus. The above findings suggest that long term ALCAR treatment may be effective in slowing down the age-related nerve cell loss in some rat brain areas.

Age-related changes of the metabolic characteristics of large, medium and small brances of the rat superior mesenteric artery were investigated in young (4 month) and old (25 month) male Wistar rats, using enzyme histochemical techniques. The following enzymatic activities were examined: lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH); NADPH(2)-tetrazolium reductase (NADPHD) and NADH(2)-tetrazolium reductase (NADHD). The intensity of enzymatic reactions within the tunica media of the large, medium and small branches and within the tunica intima of the large and medium branches of the artery was assessed microphotometrically. In young rats the reactivity of enzymes investigated is similar in both the tunica media and the intima with the exception of SDH which reacts stronger in the media than in the intima. LDH and NADHD displayed the most intense reaction whereas SDH reaction was less intense. In old rats LDH and NADPHD reactivity decreased, SDH reactivity increased in the intima of large and medium branches; and SDH increased in the media of large branches. The possibility is discussed that an impaired endothelial function may represent one of the most consistent phenomena of aging of the superior mesenteric artery.

The functional relationships between sympathetic nerve fibres and meningeal mast cells were studied in whole mounts of rat dura mater and pia-arachnoid membrane using formaldehyde histofluorescence technique. Mast cells displaying a yellow fluorescence indicative of their 5-hydroxytryptamine content were found in the dura mater, primarily perivascularly and in lesser amounts in the meningeal tissues proper without any apparent relationship with blood vessels. Bilateral removal of the superior cervical ganglion produced the degranulation of part of dura mater mast cells as well as a remarkable reduction of the intensity of their 5-hydroxytryptamine cytoplasmic fluorescence. On the contrary, the electrical stimulation of the superior cervical ganglion increased the intensity of cytoplasmic fluorescence of this kind of cells.Taken together the above data seem to be strongly suggestive of a functional link between meningeal mast cells and sympathetic nerve fibres originating from superior cervical ganglion.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide, the actions of which are mediated through interaction with specific ET receptors. Functional evidence has shown that the constrictor effect of ET may require extracellular Ca2+. Ca2+ antagonists of the dihydropyridine family attenuate the vasoconstriction caused by ET. However, the basis of the interactions between ET and dihydropyridine agents are not well understood. Our study was designed to assess whether different concentrations of ET-1 or ET-3 have any effect on [3H]nicardipine binding to sections of human renal artery. [3H]Nicardipine was specifically bound to sections of the human renal artery. Binding sites, which were located primarily over smooth muscle of the tunica media, showed the pharmacologic profile typical of a dihydropyridine Ca2+ channel. Increasing concentrations of ET-1, but not of ET-3, competed dose-dependently with [3H]nicardipine binding. A 1-nM concentration of ET-1 lessened specific [3H]nicardipine binding by approximately 80%. These results suggest the occurrence of an interaction in the human renal artery between dihydropyridine Ca2+ channels and ET-1. This interaction probably accounts for the inhibition of the ET-1-mediated vasoconstriction elicited by nicardipine.

Ca 2 + channels of the L-type were assayed in human peripheral blood lymphocytes of normotensive control subjects and of essential hypertensives using radioligand binding assay techniques. The dihydropyridine Ca 2 + channel blocker [ 3 H]( + )-PN 200-110 [isopropyl1-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methoxycarbonyl-2,6-dimethyl-3-pyridine carboxylate] was used as a ligand. [ 3 H]( + )-PN 200 110 was bound specifically to human peripheral blood lymphocytes in a manner consistent with the labeling of Ca 2 + channels of the L-type. No significant differences in the dissociation constant (K d ), in the maximum density of binding sites (B max ) or in the pharmacological profile of [ 3 H]( + )-PN 200 110 binding were found between normotensive subjects and different degree essential hypertensives. Analysis of the intralymphocytic free Ca 2 + concentration did not reveal differences between normotensive subjects and essential hypertensives. Although hypertension is associated with altered membrane handling of Ca 2 + , no changes in the expression of peripheral blood lymphocyte Ca 2 + channels of the L-type or in intralymphocytic Ca 2 + concentrations were found in essential hypertensives. Human peripheral blood lymphocytes therefore cannot represent a peripheral marker of altered Ca 2 + handling in hypertension.

Summary The pharmacological profile and the anatomical localization of a putative dopamine D4 receptor were assessed in sections of rat and human atria and ventricles using combined radioligand binding and autoradiographic techniques with [3H]-spiperone as a ligand. [3H]-Spiperone was bound specifically to sections of human and rat atria and ventricles. The binding was time-, temperature- and concentration-dependent, belonging to a single class of high affinity sites. In atria, the dissociation constant value (Kd) was 0.45 nM in rats and 0.32 nM in humans, and the maximum density of binding sites (Bmax) was 31.6 ± 2.9 fmol mg−1 tissue in rats and 18.8 ± 0.7 fmol mg−1 tissue in humans. In ventricles, Kd was 0.38 nM in rats and 0.39 nM in humans, and the Bmax was 43.5 ± 3.0 fmol mg−1 tissue in rats and 56.4 ± 3.2 fmol mg−1 tissue in humans. The pharmacological profile of [3H]-spiperone binding to sections of both rat and human atria and ventricles was consistent with the labelling of dopamine D2-like receptors. [3H]-Spiperone binding was more sensitive to displacement by the neuroleptic clozapine in sections of atria than of ventricles, suggesting the expression of a dopamine D4 receptor in atrial tissue. Moreover, preincubation of some section with a dopamine D4 receptor antibody and subsequent exposure to [3H]-spiperone caused a remarkable decrease of radioligand binding to sections of atria, but only a slight reduction of binding to section of ventricles. Light microscope autoradiography revealed the accumulation of silver grains over atrial tissue within atrial myocardiocytes. A higher density of silver grains was developed in rat than in human atria. In ventricles, silver grains were accumulated primarily in cluster areas both in rats and in humans. The above findings suggest the expression of a dopamine D4 receptor in rat atria, but not in ventricles. A similar site was identified in human atria. The possible relevance of a dopamine D4 receptor in the heart is discussed.

The pharmacological profile and the density of dopamine D 3 and D 5 receptor subtypes expressed by human peripheral blood lymphocytes of subjects of different ages (ranging from 20 to 75 years) were assessed using radioligand binding techniques. Dopamine D 3 receptor was assayed with [ 3 H]7-hydroxy-N,N-di- n -propyl-2-aminotetraline ([ 3 H]7-OH-DPAT) as a ligand. Dopamine D 5 receptor was assayed using [ 3 H][R]-(+)-(-chloro-2,3,4,5,tetrahydro-5-phenyl-1H-3-benzazepin-al-hemimaleate) ([ 3 H]SCH 23390) as a ligand. The affinity and the pharmacological profile of [ 3 H]7-OH-DPAT and [ 3 H]SCH 23390 at dopamine D 3 and D 5 receptor, respectively, were similar in subjects of different ages. The density of dopamine D 3 receptor binding sites was slightly decreased in subjects of 30–39 years in comparison with younger individuals. A remarkable loss of dopamine D 3 receptor was then found between 40 and 49 years of age in comparison with younger subjects. A further slight decrease was noticeable between 50 and 59 years of age. The number of [ 3 H]7-OH-DPAT binding sites was then stabilized after 60 years of age. The density of dopamine D 5 receptor binding sites did not show age-dependent changes. The above findings indicate the occurrence of a decline in the density of lymphocyte dopamine D 3 but not D 5 receptor between adult and mature subjects. The possibility that dopamine D 3 receptor assay in peripheral blood lymphocytes may represent a tool for investigating dopamine receptor function in aging and age-related neurological disorders is discussed.

The influence of aging and of treatment with L-deprenyl on the structure of the kidney was investigated in 24-month-old male Sprague Dawley rats by microanatomical techniques associated with image analysis. L-Deprenyl was administrated orally for 5 months at a dose not inhibiting monoamine oxidase (MAO) B activity (1.25/mg/kg/day) and at a dose inhibiting MAO B activity (5 mg/kg/day). In 24 month-old-rats the number and the volume of glomeruli was reduced in comparison with 12-month-old rats used as reference adult animals. Vascular changes characterised by increased thickness of the tunica media, decreased size of arterial lumen and increased wall-to-lumen ratio were also noticeable in 24-month-old rats. Moreover, an increased MAO B reactivity was noticeable within glomerular tufts and renal tubules. Treatment with the low dose of L deprenyl did not cause changes in MAO B reactivity, or in the number of glomeruli, but increased glomerular volume and reduced the wall-to-lumen ratio in medium-sized renal artery branches. The dose of 5 mg/kg/day of L-deprenyl significantly decreased MAO B reactivity within both glomerular tufts and tubules, increased the number and the volume of glomeruli and countered-age-related vascular changes. The above results suggest that treatment with L-deprenyl counters to some extent microanatomical changes occurring in the kidney of aged rats. The observation that the dose of the compound inactive on MAO B activity reduces in part age dependent renal microanatomical changes, indicates that the renal protective effect of L-deprenyl is only in part related to MAO B inhibition.

Ca2+ channels of the L-type were characterised in intact human peripheral blood lymphocytes using a radioligand binding technique and the dihydropyridine-type Ca2+ channel antagonist [3H](+)-PN 200-110 (isopropyl-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methoxycarbonyl-2,6-dimethyl-3-pyridine carboxylate) as a ligand. [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was time-, temperature-, concentration-dependent and of high affinity. The dissociation constant (Kd) value was 0.4 ± 0.02 nM and the maximum binding capacity (Bmax) was 33.5 ± 1.6 fmol/106 cells. Pharmacological analysis of [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was consistent with the labelling of a Ca2+ channel of the L-type. In fact, dihydropyridine derivatives were the most potent competitors of [3H](+)-PN 200-110 binding, whereas phenylalkylamine and benzothiazepine compounds or non-selective Ca2+ channel modulators were weak or ineffective displacers. These findings are the first observation that human peripheral blood lymphocytes express Ca2+ channels of the L-type. The possibility that Ca2+ channel antagonists may interfere with immune system function is discussed.

The anatomical localization of Ca2+ channels of the L-type was analyzed in sections of the human right and anterior interventricular coronary arteries by using in vitro light microscope autoradiography associated with radioligand binding techniques. [3H]Nicardipine was utilised as a ligand. Binding of the radioligand to sections of the two coronary arteries was time-, temperature- and concentration-dependent. Analysis of binding isotherms revealed a dissociation constant value of about 0.5 nM in the two arteries and maximum binding capacities of 139 +/- 6.4 fmol/mg tissue for the right coronary artery and of 173 +/- 9.5 for the anterior interventricular branch. The pharmacological profile of [3H]nicardipine binding to sections of human coronary arteries was consistent with the labelling of Ca2+ channels of the L-type. Dihydropyridine derivatives were the most powerful competitors of [3H]nicardipine binding, whereas phenylalkylamines, benzothiazepine or non-selective channel modulators were weak competitors or ineffective. Light microscope autoradiography revealed the highest density of [3H]nicardipine binding sites in the tunica media of the coronary arteries. In this layer Ca2+ channels of the L-type are located within smooth muscle cells. A lower accumulation of the radioligand occurred in the tunica adventitia, whereas no specific binding was found in the tunica intima. Study of the localization of Ca2+ channels in sections of human coronary arteries may contribute to a better understanding of the mechanism of the marked coronary dilatory activity elicited by Ca2+ antagonists demonstrable in both in vitro preparations and in vivo.

Combined radioligand binding and light microscope autoradiography techniques were used for investigating the pharmacological profile and the microanatomical localisation of dopamine receptor subtypes in the cardiovascular system and in the kidney. In superior mesenteric and renal arteries the predominant dopamine D1-like receptor belongs to the D5 (or D1b) subtype. This site is located within smooth muscle of the tunica media. The same receptor subtype predominates in the kidney, where it has a vascular and tubular localisation. The dopamine D2-like receptor subtype expressed by systemic arteries belongs to the D2 receptor subtype. It has a prejunctional and endothelial localisation. In the kidney the predominating dopamine D2-like receptor belongs to the dopamine D3 subtype. Atria but not ventricles express dopamine D2-like receptors belonging to the D4 receptor subtype. The above results suggest that in spite of the emerging complexity of the dopamine receptor profile demonstrated by molecular biology techniques, radioligand binding and autoradiographic techniques, if performed with appropriate radioligands and/or in the presence of compounds active on specific receptor subtypes, may represent a useful tool for better understanding the biological significance of peripheral dopamine receptors. (Hypertens Res 1995; 18 Suppl. I: S23-S27)

The effects of treatment with the dihydropyridine Ca+2 antagonist darodipine (PY 108-068) on age-related changes in the cerebral capillary network was studied using alkaline phosphatase histochemistry with quantitative image analysis. The investigation was performed on male Wistar rats of 12 months (adult reference group) and 27 months. The 27-month-old rats consisted of two groups, the first of control untreated animals and the second of rats receiving an oral dose of 5 mg/kg/day of darodipine from the 21st to the 27th month. The cerebral areas examined included the frontal cortex, the occipital cortex, Ammon's horn of the hippocampus, and the dentate gyrus. The number and the average length of alkaline phosphatase-positive capillaries were decreased in old rats, when compared with adult rats. The intercapillary distance, which is considered as a sensitive parameter for capillary density was increased in aged rats in comparison to adult rats. The capillary diameter was increased slightly or unchanged in old rats. The Ammon's horn and the frontal cortex were the cerebral areas most affected by age-dependent changes of the capillary network. Treatment with darodipine increased the number and the average length of alkaline phosphatase-reactive capillaries and reduced the intercapillary distance and the diameter of cerebral capillaries in old rats. The pericapillary microvenvironment of the Ammon's horn was the most sensitive to treatment with darodipine. The above results showed that treatment with darodipine is capable of counteracting some microvascular changes occurring in the brain of aged rats. This suggests that the blockade of dihydropyridine-type Ca2+ channels has a positive effect on the brain microvascular system and may counteract the impairment of pericapillary microenvironment occurring with aging.

The influence of hypertension and of treatment with the dihydropyridine calcium channel blocker isradipine on the morphology of the thoracic aorta and of the aortic tunica intima were studied. Three experimental groups of male spontaneously hypertensive rats (SHR) of 10 weeks of age were used. Two groups were treated with a daily oral dose of 0.01 mg/kg or of 0.1 mg/Kg of isradipine respectively. A third group of SHR was left untreated and served as control. Age-matched normotensive Wistar-Kyoto (WKY) rats were used as a reference group. Animals were allowed to survive for 12 weeks and were killed at 22 weeks of age. Systolic pressure values which did not change in WKY rats, significantly increased in SHR as a function of age. The dose of 0.1 mg/Kg/day isradipine reduced systolic pressure to normotensive values after the first week of treatment, whereas the lower one was ineffective. The area of the wall, the area of the tunica media and the wall-to-lumen ratio of the aorta significantly increased in SHR and decreased either with the antihypertensive and non-antihypertensive doses of isradipine. Transmission and scanning electron microscope analysis of the tunica intima revealed hypertrophy of the endothelial cells with an increase in sub endothelial space in SHR. An improvement of the endothelial morphology and a decrease in sub endothelial space was noticeable in isradipine-treated SHR. Although the hypotensive dose of the compound was the most effective, the non-hypotensive dose was active was well. The above results suggest that isradipine treatment may counter structural changes of the aorta of SHR and has a protective action on the hypertension-dependent modifications of the endothelium. The endothelial effects are probably dependent only in part by the hypotensive activity of the compound.

1. 1. The density of nerve cells and of silver-gold impregnated fibres were evaluated in the hippocampus and in the cerebellar cortex in adult (12-month-old) and old (24-month-old) Sprague-Dawley rats. 2. 2. The effects of long-term choline alfoscerate (GFC) treatment (100 mg/Kg/day for 6 months) on the above parameters were investigated in old rats. 3. 3. The number of nerve cell profiles and the area occupied by silvergold impregnated fibres were decreased both in the hippocampus and in the cerebellar cortex in old in comparison with adult rats. 4. 4. GFC treatment countered the age-dependent reduction of nerve cells and silver-gold impregnated fibres. The hippocampus was more sensitive than the cerebellar cortex to the activity of GFC. 5. 5. These results suggest that GFC treatment is effective in slowing down the expression of structural changes occurring in aging brain.

Treatment with l -deprenyl increases mean and maximum life span in the rat and reverses memory and learning deficits associated with old age. Since only sparse information is available concerning the influence of l -deprenyl administration on the aging brain microanatomy, we have investigated the effect of long-term treatment with l -deprenyl on the structure of the cerebellar cortex in the aged rat. The cerebellar cortex was used since it represents a useful model for assessing age-related changes in nervous system anatomy and function. Male Sprague-Dawley rats were treated from the 19th to the 24th month of age with a daily oral dose of 1.25 mg/kg or 5 mg/kg l -deprenyl. Age-matched rats were left untreated and used as a control group. Eleven-month-old untreated rats were used as an adult reference group. The density of Purkinje and granule neuron profiles as well as the intensity of Nissl's staining within the cytoplasm of Purkinje neurons were reduced in 24-month in comparison with 11-month rats. Moreover, an increased accumulation of lipofuscin was noticeable in the cytoplasm of Purkinje neurons of old rats as well as an increase in MAO-B activity in the molecular layer of the cerebellar cortex. The two doses of l -deprenyl increased the density of both Purkinje and granule neuron profiles and the intensity of Nissl's staining in the cytoplasm of Purkinje neurons and reduced lipofuscin deposition within Purkinje neurons. The lower dose of l -deprenyl caused only a slight decrease in MAO-B activity, whereas the 5-mg/kg/day dose remarkably reduced it. These results suggest that long-term treatment with l -deprenyl counters the expression of some age-related microanatomical changes in the rat cerebellar cortex. The possible independence of the effects of the compound on age-related microanatomical changes of the cerebellar cortex and on MAO-B inhibitory activity is discussed.

The effects of nicardipine administration on kidney morphology were studied in spontaneously hypertensive rats (SHR). Male 12-week-old SHR received an oral dose of 1 mg/Kg/day of nicardipine or vehicle for 8 weeks Age-matched Wistar-Kyoto rats were used as normotensive reference animals. At 20 weeks, the non treated SHR exhibited hypertension, albuminuria, decreased urinary sodium excretion and renal microanatomical changes. These changes were characterized by vascular alterations consisting in hypertrophy of the tunica media accompanied by a decrease of luminal surface. Glomerular changes consisting primarily in signs of glomerulosclerosis of varying degrees were noticeable in the kidneys of SHR. Treatment with nicardipine significantly reduced blood pressure and albuminuria and increased urinary sodium excretion. Moreover, hypertrophy of the tunica media and the luminal surface were decreased and increased respectively in nicardipine-treated SHR. The above results suggest that treatment with nicardipine reduces blood pressure in SHR and counteracts hypertension-dependent changes in the morphology of the kidney. The protective effect of the drug on hypertensive changes of renal microanatomy probably have functional relevance given of the influence of nicardipine treatment on albuminuria and urinary sodium excretion in SHR.

OBJECTIVE To investigate the influence of hypertension and of treatment with the vasodilator hydralazine or with the dihydropyridine calcium antagonist isradipine on the morphology of the thoracic aorta in spontaneously hypertensive rats (SHR). DESIGN The systolic blood pressure (SBP), body weight and morphology of the thoracic aorta were evaluated. The ultrastructure of the smooth muscle component of the aorta and of the tunica intima were analysed by transmission and scanning electron microscopy. METHODS The SHR were divided into three groups: a control group, which was left untreated, and two treatment groups, one with 1 mg/kg per day hydralazine and the other with 0.1 mg/kg per day isradipine. Three age-matched groups of Wistar-Kyoto (WKY) rats were included in the study: one group was left untreated and was used as a normotensive reference group, the other two groups were treated with 1 mg/kg per day hydralazine or with 0.1 mg/kg per day isradipine. RESULTS The SBP did not change in the WKY rats treated with hydralazine, with isradipine or untreated, but was significantly increased in the SHR as a function of age. Both hydralazine and isradipine significantly reduced the SBP in the SHR after the second week of treatment. Light microscopy analysis of the thoracic aorta revealed thickening of the wall of the tunica media as well as an increase in the wall: lumen ratio in the SHR. Treatment with hydralazine had no effect on the morphometric parameters evaluated, whereas isradipine administration significantly reduced the thickening of both the wall and the tunica media of the aorta, and reduced the wall: lumen ratio. No significant modifications in the structure of the thoracic aorta were noticed in the hydralazine- or isradipine-treated WKY rats compared with untreated WKY rats. Transmission and scanning electron microscopy analysis demonstrated in control SHR hypertrophy of smooth muscle cells of the tunica media, an increased size and impairment of the internal elastic lamina, and a widening of the subendothelial space. Hypertrophy of the endothelium was also noticeable in the SHR. Treatment with isradipine reduced the hypertrophy of smooth muscle cells of the tunica media and the structural impairment of the tunica intima. No effect of isradipine treatment on the morphology of the aorta was noticed in the WKY rats. CONCLUSION The present results show that the effect of isradipine was different from that of hydralazine. Both compounds lowered the SBP, but only isradipine countered the structural changes of the aorta in the SHR. The effect of isradipine administration is particularly pronounced on the hypertension-dependent changes of endothelium. This suggests that isradipine may have a protective effect on the endothelium.

The present study was designed to assess the influence of treatment with the calcium channel blocker darodipine (PY 108-068) on the morphology of pial and coronary arteries in spontaneously hypertensive rats (SHR). Twelve week male SHR were used in this study. One group was treated with a daily dose of 5 mg/Kg of darodipine, while the control group of SHR was treated with placebo. Age-matched normotensive Wistar Kyoto (WKY) rats were used as a reference group. After 12 weeks of treatment the rats were sacrificed. The brains and the hearts were removed, embedded in resin, cut and used for light microscope analysis. Darodipine treatment reduced blood pressure in SHR. Morphometric analysis of different sized pial and coronary arteries revealed decreased arterial lumen in SHR in comparison with WKY rats. The area occupied by the tunica media and the media-to-lumen ratio were increased in SHR in comparison with WKY rats. In darodipine-treated rats the area occupied by the arterial lumen was increased in comparison with control SHR, whereas the area occupied by the tunica media and the media-to-lumen ratio were decreased. Pial arteries were more sensitive than coronary arteries to darodipine treatment. Medium and small sized pial and coronary arteries were most sensitive to darodipine treatment. Large-sized coronary artery branches were unaffected by pharmacological treatment. The above results suggest that treatment of SHR with darodipine is able to reduce high blood pressure and to counter the development of structural changes of pial and coronary arteries noticeable in SHR. The higher sensitivity of the cerebral vasculature to darodipine treatment is discussed.

The purpose of this study was to ascertain if Isradipine treatment in spontaneously hypertensive rats (SHR) decreased hypertension-dependent left ventricular and coronary vascular hypertrophy. Twelve week male SHR were used in this study; one group of SHR was treated with Isradipine while the control group of SHR was left untreated. Age-matched normotensive Wistar-Kyoto rats (WKY) were utilized as a reference group. After 12 weeks of treatment rats were sacrificed. The hearts were removed and morphometric analysis was performed on the left ventricles. Isradipine treatment reduced systolic blood pressure in SHR. The heart/body weight ratio significantly increased in SHR and in Isradipine-treated SHR in comparison with WKY rats. Isradipine treatment decreased the left ventricular muscle fibre diameter and decreased the amount of focal necrosis in SHR. Different sized coronary arteries were also examined using a light microscope and an image analyzer. We found that the area occupied by the medial layer and the media-to-lumen ratio were significantly increased in comparison with WKY rats. In Isradipine-treated SHR the area of the medial layer and the media-to-lumen ratio in small and medium sized but not in large sized coronary arteries were significantly reduced in comparison with untreated SHR. The above results suggest that long term Isradipine treatment is not only able to reduce high blood pressure in SHR but is also able to counter the development of certain morphological changes often seen in the hypertensive heart and coronary arteries.

In the present study the pharmacological profile and the anatomical distribution of dihydropyridine-type Ca2+ channels were analyzed in sections of the human renal artery by the use of combined radioligand binding and autoradiographic techniques with [3H]nicardipine as a ligand. The binding of [3H]nicardipine to sections of renal artery was time-, temperature- and concentration-dependent belonging, at least in the range of radioligand concentrations used, to a single class of high-affinity binding sites. The dissociation constant (KD) value was 0.3 nM and the maximum density of binding sites (Bmax) was 248 +/- 16 fmol/mg tissue. The pharmacological profile of [3H]nicardipine binding to sections of human renal artery was consistent with the labeling of dihydropyridine-type Ca2+ channels. In fact, dihydropyridine derivatives were the most powerful competitors of [3H]nicardipine binding, whereas phenylalkilamine, benzothiazepine or non-selective channel modulators were weak or ineffective competitors. Light microscope autoradiography revealed the highest density of [3H]nicardipine binding sites in the tunica media of the renal artery, probably within smooth muscle cells. A smaller accumulation of the radioligand occurred in the tunica adventitia, whereas the tunica intima did not show specific binding. These results indicate that light microscope autoradiography techniques associated with radioligand binding may represent a useful tool for analyzing the localization of receptors or targets of drug action within the arterial wall.

OBJECTIVE The present study was designed to investigate the influence of hypertension and of long-term treatment with the dihydropyridine calcium antagonist isradipine on the morphology of the femoral artery in spontaneously hypertensive rats (SHR). DESIGN Systolic blood pressure (SBP), body weight and morphology of the femoral artery were evaluated, and the ultrastructure of the endothelium was analysed by transmission and scanning electron microscopy. METHODS SHR were divided into three groups, a control group which was left untreated and two isradipine treatment groups, one at 0.01 mg/kg per day and the other at 0.1 mg/kg per day. Two age-matched groups of Wistar-Kyoto (WKY) rats were included in the study; one group was left untreated and was used as a normotensive reference group and the other was treated with isradipine at 0.1 mg/kg per day. The study lasted 12 weeks. RESULTS SBP did not change in the WKY rats, whether treated with isradipine or not, but was significantly increased in SHR as a function of age. The lower dose of isradipine did not alter SBP in the SHR, but the higher dose brought SBP values into the normal range after the first week of treatment. Light microscopy of sections of the femoral artery did not reveal any structural differences in the five rat groups examined. Both transmission and scanning electron microscopy showed endothelial alterations in the SHR, together with thickening of the internal elastic lamina. Treatment with isradipine significantly improved the morphology of the endothelium in SHR. The higher dose was more effective, but the lower dose partly countered the hypertension-dependent changes in the morphology of the endothelium. No significant modifications to the structure of the endothelium were noticed in isradipine-treated WKY rats compared with untreated WKY rats. CONCLUSIONS The results show that structural changes occur in the endothelium of the femoral artery of SHR and that isradipine treatment has a protective effect. This protective effect is probably only partly dependent on the antihypertensive properties of the compound.

Dopexamine hydrochloride is a synthetic catecholamine proposed for the short-term treatment of heart failure and postoperative low cardiac output. The pharmacological profile and anatomical localization of dopexamine binding were investigated in sections of right and left ventricle using [3H]'-dopexamine and ligand binding techniques associated with light microscope autoradiography. Its effects on the 3-5-cyclic adenosine monophosphate (cAMP) generating system in membrane particles of the human right or left ventricle were also studied. [3H]-Dopexamine was specifically bound to sections of human right or left ventricle. The binding was time-, temperature- and concentration-dependent and was dissociable. The apparent equilibrium constant of dissociation was 3·5 nM. A decreased [3H]-dopexamine binding capacity from the base to the apex and ventricles was noticeable. The pharmacological profile of [3H]-dopexamine binding to sections of right or left ventricle was consistent with the labelling of both β2-adrenoceptors and dopamine DA-2 receptors. The most potent displacer of [3H]-dopexamine was the β2-adrenoceptor antagonist ICI 118,551 followed by dopamine, noradrenaline and domperidone. The (β1-adrenoceptor antagonist meto-prolol or the dopamine DA-1 receptor antagonist SCH 23390 were ineffective as displacers of [3H]-dopexamine binding. Light microscope autoradiography revealed the localization of [3H]-dopexamine binding sites within the wall of the human right and left ventricle. The density of silver grains was slightly higher in the right than in the left ventricle and showed a uniform transmural distribution across the ventricular wall. Silver grains, which were located primarily within myocytes, were reduced by about 80–85% by the β2-adrenoceptor antagonist ICI 118,551 and by about 15–20% by the DA-2 receptor antagonist domperidone. The concomitant presence in the incubation medium of [3H]-dopexamine, ICI 118,551 and domperidone reduced the density of silver grains to non-specific values. In membrane particle preparations of right or left ventricle, dopexamine dose-dependently increased c AMP levels. This effect was abolished by the non-selective β-adrenoceptor antagonist (–)-propranolol or by the β2-selective antagonist ICI118,551, whereas the DA-1 receptor antagonist SCH 23390 and the DA-2 receptor antagonist domperidone were ineffective. These findings suggest that the cardiac actions of dopexamine in man are mediated through interaction with β,-adrenoceplors and dopamine DA-2 receptors located within myocardial tissue. The activity of the compound on DA-2 receptors is documented by the inhibition of /3'Hj'-dopexamine binding, both in radioligand and autoradiographic experiments, by the DA-2 receptor antagonist domperidone.

OBJECTIVE The present study was designed to investigate the effect of nicardipine administration upon systolic blood pressure (SBP) and cardiac hypertrophy in spontaneously hypertensive rats (SHR). DESIGN SBP, heart: and left ventricle: body weight ratios, the cross-sectional area of cardiocytes, and the ultrastructure of the left ventricle were evaluated. METHODS Ten-week old male SHR and age-matched normotensive Wistar-Kyoto rats were studied for 12 weeks. One group of SHR was treated for 12 weeks with a daily oral dose of 1 mg/kg nicardipine and another group with 1 mg/kg hydralazine; Wistar-Kyoto rats were used as a normotensive control group. Light and electron microscope techniques associated with image analysis and morphometry were used. RESULTS Nicardipine administration normalized SBP values and significantly reduced the heart: and left ventricle: body weight ratios. Moreover, administration reduced the cross-sectional area of cardiocytes by approximately 38% in subendocardium and by 24% in subepicardium. Hydralazine administration significantly reduced SBP values but had no effect upon heart: or left ventricle: body weight ratios or the cross-sectional area of cardiocytes. Electron microscopy showed that nicardipine treatment was able to reduce the hypertension-dependent changes in cardiac ultrastructure consisting of alternations to intercalated discs and line Z morphology as well as in the decrease of the mitochondria: myofibrils ratio. CONCLUSIONS The above data indicate that nicardipine administration is able to reduce SBP and to counter the development of structural and ultrastructural changes in cardiac morphology which represent a common complication of arterial hypertension.

We used a combination of radioreceptor binding and autoradiographic techniques to study the pharmacological characteristics and anatomical localization of [3H]-quinuclidinyl benzilate (QNB) binding sites in the human right coronary artery. The ligand was bound to sections of the human right coronary artery in a manner consistent with the labelling of muscarinic receptors. The addition of pirenzepine or of carbachol to the incubation medium to generate displacement curves was indicative of the presence of M1 and M2 receptors in the right coronary artery. Autoradiography showed the localization of M1 sites primarily in the medial layer of the right coronary artery. M2 sites were located primarily in the adventitia. No [3H]-QNB binding sites were observed in the endothelium. A possible role of muscarinic receptors in the pathogenesis of coronary vasospasm is discussed.

The effects of nicardipine administration on the morphology of coronary, renal, and pulmonary vascular trees were studied in spontaneously hypertensive rats (SHRs). Male 10-week-old SHRs received 1 mg/kg/day of nicardipine or vehicle orally for 12 weeks. Age-matched Wistar-Kyoto rats were used as normotensive reference animals. Blood pressure, heart weight, heart/body weight ratio, the area occupied by the medial layer, and area occupied by the vascular wall/area of lumen ratio increased significantly (p less than 0.001) in SHRs compared with normotensive Wistar-Kyoto rats. Nicardipine reduced blood pressure, as well as relative heart weight, the area occupied by vascular smooth muscle, and the area occupied by the vascular wall/area of lumen ratio. In addition, the size of laminae of smooth muscle of the pulmonary artery was reduced in nicardipine-treated SHRs; coronary artery branches were the most sensitive. The results of the study provide direct evidence that nicardipine reduces not only blood pressure but is also able to counteract the development of hypertension-dependent changes in the morphology of the cardiovascular system.

In spite of the practical importance of having a detailed knowledge of knee joint innervation to understand the pathophysiologic aspects, little information is now available concerning the density and pattern of the nerve fibres which are distributed to it. The present study has been designed to investigate the density and distribution of nerve fibres and receptor corpuscles in the knee joint articular capsule, cruciate and collateral ligaments in the rat, using the acetylcholinesterase (AChE) histochemical in toto staining technique. The investigation was performed on male Wistar rats of 3 months of age some of which had been treated with capsaicin to deplete their afferent ‘C fibres of their content of neuropeptides. AChE-positive nerve fibres and different types of receptor corpuscle endings were found within articular capsule and ligaments. The highest density of AChE-positive nerve fibres was noticeable in the fibular collateral ligament followed by the tibial collateral ligament, the posterior cruciate ligament, the anterior cruciate ligament and the articular capsule. In the articular capsule the number of type I endings was higher than in the ligaments. The opposite is true for the other type of receptor corpuscles found as well as for nerve endings. Capsaicin treatment significantly reduced the density of AChE-positive nerve fibres in knee joint ligaments but did not affect nerve fibres in the articular capsule. Moreover, it caused the disappearance of some kind of receptor corpuscles within the collateral and cruciate ligaments. The above data collectively suggest that the AChE in toto staining technique may represent a good method for investigating joint innervation and that a significant percentage of nerve fibres supplying knee joint ligaments is represented by C fibre afferents.

Immunoreactivity for substance P (SP-LI) and vasoactive intestinal polypeptide (VIP-LI) in the stomach, duodenum, jejunum and ileum of young (3-month-old), adult (12-month-old) and old (28-month-old) male Wistar rats were determined by radioimmunoassay. SP-LI and VIP-LI did not show changes in the stomach or in the small intestine portions investigated in adult in comparison with young rats. In old rats SP-LI levels were unchanged in the stomach and in the duodenum, reduced in the jejunum and increased in the ileum. VIP-LI concentrations were unchanged in the stomach, and remarkably reduced in the duodenum, jejunum and ileum of old rats. Since the two neuropeptides investigated are localized primarily within different intrinsic gastrointestinal neurons, the present findings suggest that the various populations of gastrointestinal neurons are affected in a different manner during aging.

The influence of ageing on the noradrenergic innervation of the ovary was studied in female Wistar rats using high pressure liquid chromatography (HPLC) with electrochemical detection and catecholamine histofluorescence techniques. Old age was accompanied by a significant decrease in ovarian noradrenaline levels. In young animals (3-month-old) noradrenergic nerve fibres were distributed primarily to blood vessels and in lesser amounts to the interstitial glands. In aged animals (24-month-old) perivascular noradrenergic fibres were reduced by more than 40%; interstitial gland nerve fibres were reduced by approximately 20%. The possibility that impaired noradrenergic ovarian innervation occurring in old age may be in some way related with age-dependent failure in reproductive activity is discussed.

By the use of combined radioreceptor binding and autoradiographic techniques we attempted to analyse the biochemical characteristics and the anatomical localization of GABA-B receptors in sections of rat circle of Willis and pialarachnoid araeries. 3 H-GABA in the presence of 40 μm isoguvacine and 2·5 m m CaCl 2 was used to label GABA-B receptor sites. Sections of rat cerebellar cortex were also processed as a reference tissue. No specific 3 H-GABA binding was detectable either in radioreceptor binding or autoradiographic experiments. In contrast, the ligand was bound to sections of cerebellar cortex in a manner consistent with the labelling of GABA-B receptor sites. These findings indicate that cerebrovascular physiological responses to GABA are not linked, in the rat cerebrovascular tree, to the activation of GABA-B receptors.

The density and pattern of the sympathetic noradrenergic innervation of the extramedullary and intramedullary blood vessels of the spinal cord was studied in 3-, 12- and 25-month-old male Wistar rats using combined catecholamine histofluorescence and quantitative image analysis techniques. The study of innervation of intramedullary vessels was accomplished in spinal cord-transected rats to avoid the interference of descending spinal monoamine fibres in the observations. No age-related changes in the density of noradrenergic innervation of the anterior spinal artery or of sympathetic fibres associated with spinal cord blood vessels occurred. These results suggest that unlike perivascular noradrenergic nerves supplying the cerebrovascular tree, the sympathetic innervation of spinal cord blood vessels does not undergo age-dependent changes. It cannot be excluded that the lesser vulnerability of the spinal compared to the cerebral vascular tree to certain kinds of age-related diseases, may depend on the unchanged sympathetic trophic regulation of spinal vessels with age.

The influence of ageing on the adrenaline content of the superior mesenteric artery and vein, renal artery and vein and portal vein was studied in 3-month-(young), 12-month- (adult) and 24-month-old (old) male Wistar rats using radioenzymatic assay for the measurement of catecholamine levels. Adrenaline concentrations were unchanged in the vascular wall of the blood vessels examined in adult rats, but were significantly decreased in the vascular wall of the superior mesenteric, renal and portal veins of old rats. In contrast, no age-dependent changes of adrenaline levels were found in the vascular wall of the superior mesenteric or renal arteries. The possibility that the loss of adrenaline concentrations in the venous vascular wall may be in some way related to the cadiovascular impairment occurring with age is discussed.

Summary 1. The influence of hypertension and treatment with the dihydropyridine-type Ca2+ antagonist, nicardipine, on the structure of the kidney was assessed in spontaneously hypertensive rats (SHR) of 12 weeks of age. Treatment went for 8 weeks with a daily oral dose of 1 mg/kg of nicardipine. 2. Control SHR exhibited hypertension and microanatomical vascular and glomerular changes. Vascular changes consisted of a thickening of the tunica media and decreased luminal area of medium- and small-sized intrarenal artery branches. Glomerular changes included glomerulosclerosis and atrophy of varying degrees. 3. Administration of nicardipine significantly reduced blood pressure. The drug also decreased the thickening of tunica media and luminal narrowing of renal artery branches as well as the degree of glomerular injury in SHR. 4. These data indicate that nicardipine treatment is able to control elevated blood pressure in SHR, and to counter hypertension-dependent microanatomical impairment of the kidney. This suggests that the compound exerts a protective effect on hypertensive kidney.

The innervation of the femoral artery and vein in the dog was studied using: a) glyoxylic acid fluorescence (for the histochemical localization of adrenergic nerve fibers); b) acetylcholinesterase (for the histochemical localization of cholinergic nerve fibers). -Andrenergic nerve fibers and related terminals in both vessels are confined to the adventitial-medial transitional zone and the outer layers of the media. Acetylcholinesterase containing nerve fibers are localized in the adventitial-medial transitional zone of the femoral artery. These findings may indicate the presence of a cholinergic vasodilatator system in the control of the circulation in the femoral artery.

By the use of combined in vitro radioreceptor binding and autoradiographic techniques, we analyzed the pharmacological properties and the anatomical localization of the vasoactive intestinal polypeptide (VIP) receptor in rat superior mesenteric artery and in medium and small mesenteric artery branches. 125I-VIP was bound by sections of rat superior mesenteric artery in a manner consistent with the labeling of specific VIP receptors, with Kd and Bmax values of 0.23 nM and 0.71 pmol/mg protein respectively. Inhibition of 125I-VIP binding with VIP and related peptides gives the following rank order of potency: VIP greater than peptide histidine methionine greater than secretin. Light microscope autoradiography reveals specific VIP binding sites within the medial layer of superior mesenteric artery and its branches. Medium and small sized vessels are richer in 125I-VIP binding sites than the larger ones.

Noradrenaline levels and distribution in different components of rat knee joint were studied using radioenzymatic assay and glyoxylic acid histofluorescence techniques.The articular capsule possessed the highest noradrenaline content, and the levels of noradrenaline in cruciate ligaments were slightly higher than in collateral ligaments. In all joint components, noradrenergic nerve fibres were associated almost exclusively with the blood vessels.The possible involvement of a noradrenergic action on joint microcirculation in the pathophysiology of rheumatoid arthritis is discussed.

The distribution of acetylcholine esterase (AChE) in the ovary of normal as well as of sympathectomized guinea pigs was studied. In normal animals AChE-positive nerve fibres were found organized in a perivascular plexus. Some nerve fibres reach the corpus luteum and the follicular wall. Chemical sympathectomy performed with the neurotoxin 6-hydroxydopamine caused an almost complete disappearance of AChE positive nerve fibres suggesting that most of the AChE activity of ovarian nerves is localized in adrenergic nerve fibres. Enzyme activity was also present in smooth muscle cells of the vascular tree.

The cholinergic innervation of the pulmonary circulation was studied in man. Both extra- and intrapulmonary branches of the pulmonary artery and vein are provided with a cholinergic of the vein. In the main branches of the pulmonary vessels, the existence of two nerve plexuses, a superficial and a deep one, was observed. The superficial plexus is localized in the outer adventitial layer while the deeper plexus is localized in the adventitial-medial transitional zone. In smaller arteries and veins, the existence of a single plexus (adventitial-medial) was observed. In some specimens, the presence of diffuse masses of acetylcholinesterase (AChE)-positive material or elbow-shaped AChE-positive formations was observed. The nature of these formations as well as the possible functional role of a cholinergic system in the pulmonary circulation are discussed.

By using combined radioreceptor binding and autoradiographic techniques, we were able to localize the GABA ‘A’ receptor agonist 3 H-muscimol in the rat choroid plexus. Within sections of rat choroid plexus, 3 H-muscimol was bound specifically with a K D of 37 nM and a B max of 253 pmol/mg tissue. These values are consistent with the labelling of GABA ‘A’ receptor sites. The autoradiographic studies demonstrated that 3 H-muscimol was attached to the epithelium of the choroid plexus. The blood vessels of the plexus did not exhibit specific labelling. Examination of these data suggests the existence of GABAergic mechanisms which control cerebrospinal fluid production or flow.

The cholinergic innervation of the dura mater in the guinea pig, mouse and rat has been investigated. The dura mater is provided with a cholinergic innervation. After short incubation times (4--6 hours) we found acetylcholinesterase (AChE)-containing nerve fibers in close relationship with the main meningeal blood vessels. After longer incubation times, AChE-containing nerve fibers appear also in the meningeal tissue proper. Chemical sympathectomy, performed with the neurotoxin 6-hydroxy-dopamine, does not seem to interfere with the pattern of the dural cholinergic innervation. The findings are discussed.

The cholinergic innervation of coronary arteries and veins has been studied in the human. Structures resembling cholinergic nerve fibres are localised at the level of the extraparenchymal branches of the coronary arteries, organised in the adventitial plexus. Neither the coronary veins nor the intraparenchymal blood vessels are provided with a cholinergic innervation. Those findings are discussed.