Search

1. Oxprenolol and metoprolol (30 mg kg-1) were injected intraperitoneally (i.p.) for 1 day (acute treatment) and 6 weeks (chronic treatment) to Sprague-Dawley rats. 2. Increases of mean blood pressure and heart rate to noradrenaline (0.1-10 micrograms kg-1) and to electrical stimulation (0.5 msec, supramax V, 0.25-5 Hz) of the entire sympathetic outflow were measured in non-adrenalectomized (acute and chronic) and adrenalectomized (chronic) pithed rats. 3. Acute beta-adrenoceptor antagonist administration was without effect on mean blood pressure and heart rate increases to noradrenaline and electrical stimulation. 4. Chronic administration with oxprenolol significantly diminished the stimulation-induced increases of mean blood pressure and heart rate in non-adrenalectomized pithed rats. 5. Increases in heart rate, elicited by stimulation of the entire sympathetic outflow in non-adrenalectomized but not in adrenalectomized pithed rats, were decreased by metoprolol treatment. Both treatments were without effect on noradrenaline responses. 6. These results indicate that chronic beta-adrenoceptor antagonist treatment is associated with a reduction in the cardiovascular responses to sympathetic nerve-stimulation. However, this mechanism only operates when adrenomedullary adrenaline is present to facilitate the noradrenaline release through activation of presynaptic beta 2-adrenoceptors.

Aims: A prospective, randomised, double blind, placebo controlled study of intraoperative mitomycin C as adjunctive treatment of primary pterygium was conducted., Methods: A total of 66 eyes of 54 patients with primary pterygium were treated with excision, with or without a single intraoperative application of mitomycin C (0.1 mg/ml for 5 minutes) to evaluate the efficacy and toxicity of this adjunctive treatment. The mean follow up was 14.1 months (range 12-23 months)., Results: Of the 36 eyes that underwent simple excision, 14 (38.8%) exhibited recurrences whereas only one of 30 eyes (3.33%) treated with excision and intraoperative application of mitomycin C had recurrence (p = 0.0006). Neither serious ocular complications nor systemic toxicity were noted in the mitomycin C treated group., Conclusion: Intraoperative mitomycin C appears to be an effective and safe adjunctive treatment of primary pterygium.

1. The activity of (+/-)-laudanosine, a benzyltetrahydroisoquinoline alkaloid, was investigated in pithed rats and rat isolated aorta. Its effects on [3H]-(+)-cis-diltiazem and [3H]-nitrendipine binding to rat cerebral cortical membranes, and on the different molecular forms of cyclic nucleotide phosphodiesterases (PDE) isolated from bovine aorta were investigated. 2. The dose-response curve to methoxamine (3-300 micrograms kg-1, i.v.) in normotensive pithed rats was shifted to the right by (+/-)-laudanosine, 3 and 6 mg kg-1. 3. (+/-)-Laudanosine inhibited in a concentration-dependent manner the contractile responses evoked by noradrenaline (NA 1 microM), depolarizing solution (KCl 80 mM) or depolarizing solution plus phentolamine (10 microM) in rat isolated aorta. The alkaloid appeared to be more potent against NA-induced contractions. 4. In Ca(2+)-free solution, (+/-)-laudanosine (100 microM) inhibited the contraction evoked by NA and did not modify the phasic contractile response evoked by caffeine. The alkaloid did not modify the refilling of the intracellular Ca(2+)-sotres sensitive to NA or caffeine. 5. (+/-)-Laudanosine inhibited [3H]-prazosin binding to cortical membranes and also inhibited [3H]-(+)-cis-diltiazem but with a lower potency. [3H]-nitrendipine binding was not affected by laudanosine. 6. (+/-)-Laudanosine does not have a significant effect on the different forms of PDEs isolated from bovine aorta. In contrast, compounds structurally related to this alkaloid such as papaverine and its derivatives, had a non-selective or more specific inhibitory effect on these PDE forms. These differences can be explained on the basis of their structural features: the planarity of the isoquinoline ring(papaverine) facilitates the interaction with receptor sites, and the different position of the benzyl group does not modify the activity unless this position leads to the presence of a chiral centre (laudanosine).7. These results suggest that (+/-)-laudanosine has a selective activity as an alpha1-adrenoceptor blocker. Its lack of action on different PDE forms provides us with information about a group of benzylisoquinolines that with small structural changes show a different effect on PDE-forms isolated from vascular smooth muscle.

We used the reverse hemolytic plaque assay (RHPA), a method for detecting secretion by single cells, to demonstrate functional heterogeneity among prolactin (PRL) cells of rat anterior pituitary at the light microscopic (LM) level. We attempted to adapt RHPA for electron microscopy (EM) to define the relationships between fine structure and secretory activity in individual PRL cells. A major modification of the technique, intended to improve preservation of ultrastructure, was allowing the cells to recover after their enzymatic dispersion from the pituitary tissue, through a brief (3-4 hr) culture step before the assay. Adaptation for EM was achieved by the use of plastic slides for construction of specialized Cunningham chambers, permitting application of all the EM procedures (flat embedding, punching of selected areas) usually employed for cultured pituitary monolayers. Moreover, immunocytochemical pre- and post-embedding methods were also applied for cell identification and study of subcellular hormone distribution. Such a modified RHPA enabled us to analyze the ultrastructure of plaque-forming cells surrounded by their companion red blood cell ghosts. The first results with EM RHPA showed that under basal conditions a subpopulation of PRL cells containing small granules (150-200 nm) was actively secreting, whereas PRL cells with large (300-600 nm) and irregular granules appeared to be stimulated by thyrotropin-releasing hormone or KCl. The EM RHPA technique described here might receive more general application and could be utilized for study of many other secretory systems.

The relation between norepinephrine (NE)-induced contraction and inositol phosphate (IP) formation was investigated in aorta and tail artery rings from adult spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Norepinephrine (NE) contracted the tail artery of WKY and SHR with similar potency (-log EC50 6.6 +/- 0.1 and 6.5 +/- 0.08, respectively), but the maximum tension developed by SHR (0.98 +/- 0.03 g weight) was greater as compared with WKY (0.75 +/- 0.09 g weight). [3H]IP accumulation in the NE-stimulated tail artery was enhanced (p < 0.05-0.01) in SHR as compared with WKY, the potency exhibited being similar in both groups of rats. In aortic rings, in contrast, sensitivity to NE was reduced in SHR as compared with WKY rats (-log EC50 7.92 +/- 0.16 and 8.44 +/- 0.14, respectively) whereas the maximum developed tension was similar. There was also a nonsignificant trend for [3H]IP formation to be impaired in SHR as compared with WKY. Furthermore, results obtained in Ca(2+)-free medium appears to indicate that the contribution of intracellular calcium to NE-induced contraction is greater in tail artery than in aorta. Together, these data suggest that differences in alpha 1-adrenoceptor-mediated contraction observed between blood vessels of SHR and WKY are associated with qualitatively similar alterations in the [3H]IP accumulation linked to alpha 1-adrenoceptor stimulation.

To study potential cardiac alpha 1-adrenoceptor changes in the stage of established hypertension, [3H]prazosin binding characteristics and norepinephrine (NE) stimulated production of inositol phosphates in the ventricular tissue of spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto control rats (WKY) were determined. The maximum number of cardiac [3H]prazosin binding sites was significantly reduced in SHR as compared with WKY rats, but the Kd values were similar in both groups of animals. Distribution of the [3H]prazosin-labeled high- and low-affinity binding sites for WB 4101 was similar in SHR and WKY rats. Pretreatment of ventricular heart membranes with the irreversible alpha 1B-adrenoceptor-selective antagonist chloroethylclonidine resulted in the same percentage of loss of specific [3H]prazosin binding in both groups of rats. Together, these results showed a similar ratio of alpha and alpha 1B-adrenoceptor subtypes in SHR and WKY rats. In addition, [3H]inositol phosphate accumulation in response to cardiac alpha 1-adrenoceptor stimulation by NE was significantly reduced in SHR as compared with WKY rats although the EC50 values were not significantly different in the two strains of animals. Thus, we conclude that in an established stage of hypertension there is a specific loss in the number of cardiac alpha 1-adrenoceptors with consequently reduced inositol phosphate turnover. These results are compatible with the reported decrease in the positive inotropic effect mediated through myocardial alpha 1-adrenoceptors in spontaneous hypertension.

1. Neuropeptide Y (NPY) increased inositol phosphate (IP) formation in the femoral artery and vein of adult Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. 2. Noradrenaline (NA, 10(-6) M) induced IP accumulation in both strains of rats. 3. Subthreshold concentrations of NPY (3 x 10(-9) M for femoral vein and 10(-8) M for femoral artery) failed to modify NA (10(-6) M)-induced IP formation in both vessels. 4. These results suggest that the direct contractile effects but not the potentiation of NA-induced contractions may be directly linked to phosphatidylinositol turnover in adult SHR and WKY rats.

1. The effects of neuropeptide Y (NPY) were examined on adrenergic and non-adrenergic, non-cholinergic (NANC) neurotransmission in the rat anococcygeus muscle. 2. NPY (0.1-0.3 microM) greatly potentiated the contractile responses induced by field stimulation. Prazosin (0.1 microM) completely abolished the stimulation-induced responses either in the absence or presence of NPY. 3. NPY (0.1-0.3 microM) enhanced only the contractile responses to low doses of noradrenaline (NA, 0.003-0.01 microM). Responses to tyramine were unaffected by the same concentrations of NPY. 4. In superfused anococcygeus, previously loaded with [3H]-NA, NPY (0.1-0.3 microM) failed to modify the basal, as well as the stimulation-evoked, release of tritium at 2 and 4 Hz. 5. NANC relaxations induced by electrical stimulation were significantly reduced, in a concentration-related manner, by 0.1-0.3 microM NPY. 6. L-NG-nitro-arginine (L-NOARG, 30 microM) enhanced the stimulation (0.25-1 Hz)-induced motor responses. In the presence of L-NOARG (30 microM), NPY (0.1 microM) did not modify the motor responses induced by field stimulation (0.25-0.5 Hz). L-Arginine did not reverse the NPY-induced potentiation of stimulation-induced motor responses. 7. The relaxations of anococcygeus muscle induced by sodium nitroprusside (SNP, 0.01-0.3 microM) were diminished by NPY (0.1-0.3 microM). 8. Our study suggests that NPY, at concentrations devoid of contractile effect, potentiates the motor responses of rat anococcygeus muscle as a consequence, at least in part, of the inhibition of NANC relaxing responses by a different mechanism from L-NOARG.

The distribution of four basement membrane components: laminin (LAM), type IV collagen (Coll. IV), heparan-sulfate proteoglycan (HSPG), and entactin (ENT), was studied by immunocytochemistry in primary cultures of adult rat anterior pituitaries. In such cultures, the pituitary cells are deprived of their normal environment of adjacent cells and basement membranes (BM), and of the connectivo-vascular system of the hypophysis. In this dissociated system, pituitary cells grow as small clusters upon a monolayer of fibroblasts. LAM was found highly expressed in endocrine and in folliculo-stellate cells. Very small amounts of Coll. IV, but neither HSPG nor ENT, could be detected in endocrine cells. In contrast, in fibroblasts, very large amounts of Coll. IV, HSPG, and ENT, and a lower quantity of LAM were detected. At the ultrastructural level, the immunoreactive components present within the cells were located in the subcellular compartments involved in the elaboration of exported products. In addition to that intracellular distribution, the four constituents were observed in an extracellular matrix which appeared between the cultured cells, either as an amorphous material, or as a more or less dense reticular network, weakly stained with anti-LAM, but strongly stained with the other antibodies. Thus, the present immunocytochemical data support the implication of pituitary endocrine cells, at least for LAM secretion, in the elaboration of a novel extracellular matrix in primary cultures. In addition, a cooperation with non-endocrine cells seemed to be required for the production of the four BM components.

The distribution of three components of basement membranes (BM): heparan-sulfate proteoglycan (HSPG), entactin (ENT), and type IV collagen (Coll. IV), was studied in the adult rat anterior pituitary and compared to the distribution of laminin (LAM) described in an earlier report (Vila-Porcile et al., 1987, J. Histochem. Cytochem., 35, 287). Several immunocytochemical methods were applied at both light and electron microscope levels. The three components were detected in all the pituitary BM and in endothelial and perivascular connective cells, as previously observed for LAM. In contrast to the prominent labeling previously observed for LAM within epithelial cells, however, only a faint immunoreaction could be detected for the other components, with nonetheless a discrete signal for Coll. IV. These findings indicate that 1) the four studied components are present in all the BM of the rat anterior pituitary; 2) pituitary endocrine cells contain LAM, and to a lesser extent Coll. IV, and thus could participate to the elaboration of the BM; and 3) the presence of the four components in non-epithelial cells also suggests their cooperation in BM building. The questions of the turnover and intracellular pathways of each of these components were addressed but remain unanswered.

1. Total inositol phosphate formation was measured in labelled femoral and iliac arteries and veins of 14 week-old spontaneously hypertensive rats (SHR) and age-matched Wistar Kyoto (WKY) controls, either unstimulated or in the presence of noradrenaline. 2. Basal levels of [3H]-inositol phosphates and [3H]-phosphatidylinositol were significantly enhanced in SHR femoral artery, but not in the other 3 vessels, compared with WKY. 3. Noradrenaline stimulated phosphoinositide hydrolysis in all four vessels of SHR and WKY. Pretreatment with prazosin (10(-7)-10(-6) M) but not with yohimbine (10(-7) M), inhibited the noradrenaline-induced inositol phosphate formation indicating an alpha 1-adrenoceptor-mediated response. 4. In the femoral artery of SHR compared to WKY, [3H]-inositol phosphate accumulation induced by noradrenaline (10(-7)-10(-5) M) was significantly reduced when expressed relative to basal values although the response to higher concentrations (10(-4)-10(-3) M) was not altered. In contrast, a significant reduction of inositol phosphates was seen only with 10(-7) M noradrenaline when absolute values were compared. In the other three vessels, no difference in noradrenaline-induced [3H]-inositol phosphate formation was observed between strains. 5. These data suggest that phosphoinositide hydrolysis-mediated by alpha 1-adrenoceptors may be reduced in some but not all blood vessels of adult SHR.

We repaired the anterior cruciate ligament of the knee using a Dacron prosthesis in fifty-four patients. Nineteen patients had an acute injury of the anterior cruciate ligament, and thirty-five had a chronic rupture. In each patient, only one knee was involved. In twenty-six patients, the prosthesis was implanted arthroscopically, and in twenty-eight, the operation was done by arthrotomy. The length of follow-up ranged from two to five years. In thirty-one patients, a second arthroscopy of the knee was done at follow-up, and the findings were recorded. Only twenty-three patients were free of symptoms at the latest follow-up. Stability and the scores on the grading system of Lysholm and Gillquist were excellent in the first postoperative year; the results worsened due to complications occurring in the second year of follow-up. There were no differences in the results between patients who had a closed procedure and those who had an open procedure. No differences were noted between the patients who had an acute injury and those who had a chronic rupture. Twenty-six failures were directly related to the prosthesis, including rupture of the femoral insertion (thirteen) or tibial insertion (three), rupture of the central body (seven), and elongation in continuity (three). We concluded that a free Dacron prosthesis that is used to replace or supplement a torn anterior cruciate ligament is not a durable substitute for that ligament.

Ten normal children (mean age = 9 years) and 12 dyslexic children (mean age = 8.1 years) were compared for latency, amplitude and topographic distribution of both parameters of P300. We found a significant increase in P300 latency in the dyslexic group. Noteworthy is the increase in amplitude in the central parietal area in the control group. These facts and their incidence are discussed in the present study.

1. The effects of neuropeptide Y (NPY) on the cardiovascular responses induced by stimulation of pre and postjunctional alpha 2-adrenoceptors were studied in the pithed normotensive rat. 2. The increase in diastolic blood pressure induced by cumulative injection of xylazine (1-1000 micrograms kg-1, i.v.) were potentiated by NPY (5 micrograms kg-1) but not affected by a lower dose (0.75 micrograms kg-1) of this peptide. 3. Xylazine (1-100 micrograms kg-1) inhibited in a dose-dependent manner the tachycardia induced by continuous electrical stimulation (0.2 Hz, 2 ms, 60 V) of the spinal cord (C7-Thl). 4. NPY (5 micrograms kg-1 but not 0.75 micrograms kg-1) enhanced the inhibitory effect of xylazine on the tachycardia induced by electrical stimulation without having any direct effect on heart rate. 5. These results suggest that there may be a positive interaction between NPY receptors, postjunctional alpha 2-adrenoceptors and between NPY receptors and postjunctional alpha 2-adrenoceptors in the cardiovascular system of the rat.

The effects of a single administration (48 hours) and of chronic (14 days) treatment with tricyclic (desipramine, nortryptiline) and nontricyclic (mianserin, nomifensine) antidepressant drugs on responses of the isolated anococcygeus muscle to the alpha 2-adrenoceptor agonist xylazine (inhibition of contraction to field stimulation at 1 Hz) and to the alpha 1-adrenoceptor agonist phenylephrine (contraction of the muscle) have been studied. Of the drugs used only desipramine and nortryptiline administered chronically reduced the responsiveness of the anococcygeus muscle to phenylephrine suggesting a desensitization of postsynaptic alpha 1-adrenoceptors. Long-term but not acute administration of antidepressants resulted in significant decrease in sensitivity of presynaptic alpha 2-adrenoceptors to xylazine. These results show that the adaptative changes of alpha-adrenoceptors in the rat anococcygeus muscle following long-term administration may depend on the efficiency to inhibit the neuronal uptake and the ability to antagonize alpha 1-adrenoceptors.

Specimens of the hermit crab Dardanus arrosor go indistinctively towards any of the arms of a T-maze if lighting is uniform. The difference between the probabilities of going towards one arm rather than the other tends to zero as the number of trials is increased. If only one of the arms is lightened, hermits go preferably towards the dark one: The difference between the two probabilities tends to 0.500. If the animals attracted by the dark zone are electroshocked (60 V, 2.5 seconds) near their oral zone, the probability of going towards the light zone increases (statistically significant). Differences between the learning abilities of both sexes are not significant.

The effect of chronic treatment (10 days) with thioridazine (25 mg/kg per day, i.p.) on the increase in diastolic blood pressure induced by methoxamine and xylazine was studied in the pithed rat. The dose-response curve for methoxamine, but not for xylazine, was shifted to the left by the neuroleptic. These results indicate that postjunctional alpha 1-adrenoceptors in the rat blood vessels become supersensitive after long-term treatment with thioridazine.

Transsphenoidal pituitary surgery was performed in 64 patients with Cushing's disease in search of a corticotroph adenoma. In 4 patients, profuse local bleeding prevented completion of the exploration. Of the 60 patients who had an adequate exploration, 4 could not be followed after surgery. Short term assessment of the surgical outcome (3-6 months postoperatively) was performed on 60 patients, including the 4 who had incomplete pituitary exploration. Forty-two patients (70%) were judged as immediate successes [urinary cortisol excretion, less than 90 micrograms (less than 248 nmol)/day]; the mean urinary cortisol excretion and plasma ACTH level fell from 463 +/- 70 (+/- SE) to 26.7 +/- 3.6 micrograms/day (1277 +/- 193 to 74 +/- 10 nmol/day; n = 33) and from 111 +/- 33 to 36 +/- 14 pg/mL (24 +/- 7 to 8 +/- 3 pmol/L; n = 23) in patients who had both measurements pre- and postoperatively. Eighteen patients (30%) were judged as immediate failures; neither urinary cortisol excretion nor plasma ACTH levels changed significantly in patients who had both measurements pre- and postoperatively. The preoperative epidemiological, clinical, hormonal, and radiological characteristics of the 2 groups were similar. Histological examination of pituitary fragments removed in 58 of the 60 patients evaluated postoperatively revealed the presence of tumoral tissue in a higher percentage of patients in the immediate success group (72%) than in the immediate failure group (24%; P less than 0.01). The 42 patients in the immediate success group were followed from 6 months to 7 yr (median, 2 yr); 6 patients had recurrences from 2-3 yr after operation. Actuarial analysis indicates that the probability of a patient remaining well 6 yr after surgery is 72 +/- 20% (95% confidence limit). Most of the patients in the immediate success group had transient ACTH deficiency preceding a progressive return to normal pituitary-adrenal function.

Following the immunodetection of laminin in basal laminae and within some glandular cells of adult rat pituitary (Tougard et al., 1985: In Vitro 21:57), the present work had a double purpose: (a) adjustment of optimal conditions to detect laminin at both the cellular and subcellular level with an immunoperoxidase pre-embedding procedure, and (b) identification of the hormonal specificity of the laminin-containing cells, based on development of a "two-step" method combining the pre- and post-embedding approaches. In addition to extracellular localizations (basal laminae and connective tissue compartment), laminin was detected intracellularly within membrane-bounded compartments in all endocrine cell types and in the folliculo-stellate cells. It was found in rough endoplasmic reticulum cisternae, in a few Golgi saccules, and in vesicles or vacuoles. Labeled secretory granules were observed in gonadotrope, thyrotrope, and corticotrope cells but were very scarce in prolactin cells and absent in somatotrope cells. In addition, exocytotic profiles of labeled granules were frequent, suggesting a granular pathway for laminin export. Labeled vesicles, heterogeneous in size and shape, were observed mostly in prolactin cells. They might represent either a vesicular pathway for laminin export or an endocytic route for membrane-bounded laminin. These results bring complementary data to the concept that epithelial cells elaborate their basement membranes (Pierce and Nakane, 1967: Lab Invest 17:499). Moreover, the subcellular distribution of laminin within organelles involved in the biosynthesis, transport, and even in the storage of secretory products suggests that laminin might be exported by glandular pituitary cells according to different pathways.

The interaction of bromocriptine with several catecholamine receptors that control the sympathetic responses at cardiac and vascular level has been studied in pithed adrenalectomized and vagotomized normotensive rats. Bromocriptine (30 and 100 micrograms/kg) inhibited the stimulation-induced pressor responses in the pithed rat without modifying the pressor responses induced by noradrenaline. Sulpiride (0.3 mg/kg) abolished the effects of bromocriptine (30 micrograms/kg) but only partially prevented the effects of bromocriptine (100 micrograms/kg) on the stimulation-induced pressor responses. Yohimbine (0.3 mg/kg) partially antagonised the inhibitory effect of bromocriptine on stimulation-induced pressor responses. Combination of yohimbine and sulpiride abolished attenuation of the stimulation-induced pressor responses by bromocriptine (100 micrograms/kg). Bromocriptine (0.3 and 1 mg/kg) shifted to the right the frequency-response curve of increases in heart rate. This effect was prevented by yohimbine (0.3 mg/kg) but not by sulpiride (0.3 mg/kg). The same doses of bromocriptine were ineffective on heart rate increases induced by noradrenaline. Bromocriptine (0.3 and 1 mg/kg) shifted to the right the increases in diastolic blood pressure induced by methoxamine without modifying those induced by xylazine and noradrenaline. These results suggest that bromocriptine acts on the peripheral sympathetic nervous system of the pithed rat as an agonist of presynaptic dopamine receptors and alpha 2-adrenoreceptors and as an antagonist of postsynaptic alpha 1-adrenoreceptors.

1. Experiments were performed to determine the activity of four antipsychotic drugs on several catecholamine receptors that control the sympathetic cardiovascular responses in rats. 2. Chlorpromazine, thioridazine (0.03 and 0.1 mg kg-1) and haloperidol (0.3 and 1 mg kg-1) inhibited methoxamine-induced diastolic blood pressure increases in the pithed rat, whereas sulpiride (1 and 3 mg kg-1) was without effect. 3. Only sulpiride (3 mg kg-1) antagonized the pressor responses induced by xylazine. 4. Xylazine inhibited the heart rate increase induced by electrical stimulation of the spinal cord (C7-Th1) in the pithed rat. This effect was partially prevented by sulpiride (1 and 3 mg kg-1) and chlorpromazine (0.3 mg kg-1). A higher dose of chlorpromazine (1 mg kg-1) abolished the inhibitory effect of xylazine. 5. Apomorphine infusion inhibited the pressor responses induced by electrical stimulation (Th5-L4) in pithed rats. This effect was reversed by sulpiride (0.01, 0.03 and 0.1 mg kg-1) and partially antagonized by haloperidol (0.1 mg kg-1). 6. The depressor response to fenoldopam in anaesthetized rats was only inhibited by the higher dose of chlorpromazine and thioridazine (3 mg kg-1). 7. Our results suggest that, in the peripheral nervous system of the rat, haloperidol and sulpiride act as antagonists of DA2 receptors while chlorpromazine and thioridazine antagonized DA1 receptors. Furthermore, thioridazine and haloperidol show alpha 1-adrenoreceptor antagonist properties, whereas sulpiride antagonizes alpha 2-adrenoreceptors. Chlorpromazine shows mixed alpha 1/alpha 2-adrenoreceptor antagonism.

The influence of piribedil on cardiovascular sympathetic responses has been studied in the pithed rat. Piribedil (0.3-1 mg kg-1) inhibited the increases of diastolic blood pressure induced by spinal cord electrical stimulation at the level Th5-L4. This effect was reversed by sulpiride (0.3 mg kg-1) but not by yohimbine (0.3 mg kg-1). The cardiovascular responses induced by noradrenaline were unaffected by piribedil (0.3-1 mg kg-1). However piribedil (0.3-1 mg kg-1) did not modify the heart rate increase induced by spinal cord electrical stimulation at the C7-Th1 level. These results suggest that piribedil inhibits the vascular sympathetic transmission in the pithed rat via stimulation of presynaptic dopamine receptors.

A group of 62 patients were examined for the adaptometry curve and the static central field in the early postoperative period following an operation for detached retina by various techniques. Comment is made of the data obtained with reference to extension of the detachment, reoperated cases, and results in general.

For this experience report we have selected out of a total of 950 eyes with retinal detachment, 373 eyes and have sorted them out into three study groups: myopia over 8 d (197 eyes including 14 bilateral detachments), surgical aphakia (102 eyes) and traumatic detachment (74 eyes). With the help of tables and figures we tried to point out the form, number and localization of retinal tears in the eyes with retinal detachment in the above-mentioned groups. For fundus examinations we used routinely the binocular indirect ophthalmoscope without and with scleral depressor and the Goldmann three-mirror contact glass, also without and with scleral depressor. The striking features of the main types of retinal breaks in the three groups are commented, statistically analysed and compared.

Laminin (LAM), a glycoprotein component of basement membranes, has been previously detected within several subcellular compartments of prolactin (PRL) cells in the pituitary gland. The present work was aimed at comparing the subcellular localization of PRL, a specific secretory product, with that of LAM, in relation to the secretory activity of PRL cells. LAM and PRL were located in parallel, by ultrastructural immunocytochemistry, in PRL cells of lactating female Wistar rats, either stimulated by suckling, or blocked by weaning, or reactivated by suckle following short-term weaning. Variations in physiological conditions were correlated with a redistribution of PRL immunoreactivity within morphologically modified compartments. The Golgi apparatus became hypertrophied, and PRL impressively accumulated within saccules of the Golgi stacks of blocked cells. On the contrary, no apparent changes occurred in LAM distribution, at least at the Golgi level. Only a slight increase of LAM immunoreactivity was observed in rough endoplasmic reticulum after a long weaning period. PRL could be detected in most of the secretory granules and particularly in forming elements, whereas LAM was observable at the peripheral edge of some mature granules. Such a labeling was not markedly influenced by the physiological state. The prominent structures, indicative of crinophagic activity, characteristic of blocked cells, contained masses of dense material, which were always immunopositive with antibodies to PRL, but never to LAM. These observations could suggest that, in PRL cells, intracellular transport and exportation of LAM are controlled by mechanisms independent from those involved in the regulation of PRL secretion.

As early as 1932, basophil cells have been considered to be involved in the corticotropic and melanotropic functions due to their proliferation during Cushing's disease. Later on, opposite opinions were held and other cells suggested to be implied in the tumor process: chromophobe, acidophil or even follicular cells. Moreover, new categories of basophil cells have been evidenced through sophisticated staining methods, in animal and human pituitaries. At the same time, the prevalent dogma 'one hormone-one cell' raised the problem of the search for both a corticotroph and a melanotroph in the human pituitary, which is devoid of an intermediate lobe. Since 1960, immunocytochemistry became a reliable method and simultaneously new peptides have been found. However, these peptides share common sequences of amino acids, thus raising questions as to the specificity of the antisera. Most authors mention the reaction to the basophil cells previously considered as melanotrophs and called beta or R [here beta(R)]. These large rounded cells, showing red granules after Alcian blue-PAS staining, are mostly located in the median area of the anterior lobe, in the cystiform zone and in cell cords invading the neural lobe. In the fetal pituitary, reactivity is observed either in some differentiated beta(R) cells or, earlier, in chromophobe cells. The question is now raised whether one cell may contain several peptides and, in this case, whether the different peptides are carried by the same granule. Technical procedures using numerous antisera on serial sections have shown associations at the level of a given cell (and of a given granule under the electron microscope). However, dissociations are also to be noticed, as far as ACTH and beta-MSH (adult) and more particularly alpha-MSH (adult and fetus) are concerned.

To determine the incidence of ranitidine-induced myelosuppression in the bone marrow transplant setting, we reviewed the records of all patients at our institution (223) who received ranitidine while undergoing bone marrow transplantation. We identified 37 cases in which a myelosuppressive episode was temporally associated with ranitidine use. In-depth analysis of the 37 cases showed 12 in which no alternative cause could be found and in which strong evidence for a ranitidine effect existed. Three of these cases are included herein as case reports. Based on this series, the overall incidence of ranitidine-induced myelosuppression in bone marrow transplant patients was approximately 5% (12/223).

58 cases of Cushing's disease were studied after selective transsphenoidal surgery, by means of histology, immunocytochemistry and morphometry. The qualitative and quantitative results, related to the clinical follow-up of the patients indicated that: 1) when a well-defined tumor was found (62% of the patients), successful outcomes occurred in 88% of the cases, 2) when a tumor could not be found, successful outcomes amounted to only 33% of the cases, a rate that might be related to a surgical exploration of the basophil cell zone "invading" the neural lobe, thus questioning a role of this zone, at least in some Cushing's diseases.

1. Ergotamine (3-10 micrograms/kg) inhibited the electrical stimulation-induced pressor and cardiac responses without modifying pressor responses of noradrenaline and tyramine in the pithed rat. 2. Yohimbine (0.3 mg/kg) partially prevented the ergotamine cardiac and vascular inhibitory effects but sulpiride (0.3 mg/kg) only prevented it at vascular level. Both antagonists together abolished the ergotamine inhibition of electrical stimulation-induced pressor responses. 3. The cumulative dose-response curve of ergotamine (1-100 micrograms/kg) vasoconstrictor effects was partially inhibited to the same extent by prazosin (1 mg/kg) and yohimbine (0.3 mg/kg). A greater inhibition was observed with both antagonists administered together. 4. Ergotamine (30 micrograms/kg), in presence of yohimbine, inhibited the pressor responses of methoxamine, without any effect on xylazine pressor responses. 5. These data indicate that ergotamine acts as an agonist of both the presynaptic dopamine receptors and alpha 2-adrenoceptors, of alpha 1 and alpha 2-postsynaptic adrenoceptors, and also as an antagonist of the postsynaptic alpha 1-adrenoceptors.

The experiments concerned the contractile responses of rat anococcygeus muscle to the selective alpha 1-adrenoceptor agonists cirazoline, phenylephrine, methoxamine, St 587, Sgd 101/75, amidephrine and SK&F 89748-A and the effect of the calcium entry blocker D600 on the responses. The effects of noradrenaline, adrenaline, K+, tyramine and electrical field stimulation were studied as well. The potency series of the various agonists on rat anococcygeus muscle differed from the series for rat and guinea-pig aorta, indicating differences in the structure of the alpha 1-adrenoceptors on these tissues. D600 was ineffective in inhibiting contractions of rat anococcygeus muscle to the various agonists, but effectively attenuated the responses to K+ in anococcygeus muscle from rats pretreated with reserpine or in prazosin-induced preparations. These data indicate that alpha 1-adrenoceptor activation in rat anococcygeus muscle triggers contractions which do not primarily require the influx of extracellular calcium. In this respect, the smooth muscle from the rat anococcygeus muscle differs from vascular smooth muscle from this species.