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Abstract Background Recent advances in optical coherence tomography (OCT) technology allow a more accurate choroidal visualization. The aim of this study is to provide histochemical analysis with induced fluorescence images of the choroidal stromal, vascular and nerve network, highlighting possible correspondences with OCT and OCT angiography (OCT-A) analysis. Methods The material examined with a histochemical process of induced fluorescence through condensation of biologically active monoamines with glyoxylic acid was obtained from 6 eyes enucleated for malignant melanoma and ciliary body neoplasia. The resulting images have been qualitatively compared with OCT and OCT-A choroidal images obtained from 10 volunteers, in order to identify possible relationships. Choriocapillary segmentation was performed automatically through the embedded analysis software, while segmentation of Sattler’s and Haller’s layers was performed through a manual method. Results Histochemical analysis provided accurate visualization of choroidal adrenergic innervation across all layers and its relationships with blood vessels and melanocytes. The above structures were not visualized at OCT and OCT-A which provided good visualization of blood vessels in Sattler’s and Haller’s layers as well-delimited hyporeflective areas. Decorrelation signal was not detected in OCT-A analysis due to low blood flow velocity in external choroidal layers. Conclusions The choroid is an extremely dynamic structure which deserves to be analyzed in vivo since it is involved in the pathogenesis of several ocular conditions. Direct evaluation of the activity of choroidal nerves and melanocytes is still not possible with OCT and OCT-A, even if they are capable of providing a satisfactory representation of choroidal vascularization.

Various lymph node functions are regulated by the sympathetic nervous system as shown in rodent studies. If human lymph nodes show a comparable neural regulation, their afferent nerves could represent a potential therapeutic target to treat, for example, infectious or autoimmune disease. Little information is available on human lymph node innervation and the aim of this study is to establish a comprehensive and accurate representation of the presence and location of sympathetic nerves in human lymph nodes. Since previous studies mention sympathetic paravascular nerves to occasionally extent into T cell‐rich regions, the relation of these nerves with T cells was studied as well. A total number of 15 inguinal lymph nodes were resected from six donated human cadavers. Lymph node sections were stained with HE and a double T/B cell staining for evaluation of their morphology and to screen for general pathologies. A triple stain was used to identify blood vessels, sympathetic nerves and T cells, and, to study the presence and location of sympathetic nerves and their relation to T cells. To evaluate whether the observed nerves were en route to other structures or were involved in local processes, adjacent slides were stained with a marker for varicosities (synaptophysin), which presence is suggestive for synaptic activity. All lymph nodes contained sympathetic nerves, both as paravascular and discrete structures. In 15/15 lymph nodes, nerves were observed in their capsule, medulla and hilum, whereas only 13/15 lymph nodes contained nerves in their cortex. The amount of sympathetic nerves varied between compartments and between and within individuals. In general, if a lymph node contained more paravascular nerves in a specific compartment, more discrete nerves were observed as well. Occasionally, discrete nerves were observed in relation to T cells in lymphoid tissues of the cortex and medulla. Furthermore, discrete nerves were frequently present in the capsule and hilum. The presence of varicosities in a portion of these nerves, independently to their compartment, suggested a local regulatory function for these nerves. Human lymph nodes contain sympathetic nerves in their capsule, trabeculae, cortex, medulla and hilum, both as paravascular or as discrete structures. Discrete nerves were observed in relation to T cells and non‐T cell‐rich areas such as the hilar and capsular connective tissue. The presence of discrete structures suggests neural regulation of structures other than blood vessels, which was further supported by the presence of varicosities in a portion of these nerves. These observations are of relevance in further understanding neural regulation of lymph node immune responses and in the development of neuromodulatory immune therapies. [ABSTRACT FROM AUTHOR]

This study investigated the role of CDK4 in the oxidative metabolism of brown adipose tissue (BAT). BAT from Cdk4−/− mice exhibited fewer lipids and increased mitochondrial volume and expression of canonical thermogenic genes, rendering these mice more resistant to cold exposure. Interestingly, these effects were not BAT cell‐autonomous but rather driven by increased sympathetic innervation. In particular, the ventromedial hypothalamus (VMH) is known to modulate BAT activation via the sympathetic nervous system. We thus examined the effects of VMH neuron‐specific Cdk4 deletion. These mice display increased sympathetic innervation and enhanced cold tolerance, similar to Cdk4−/− mice, in addition to browning of scWAT. Overall, we provide evidence showing that CDK4 modulates thermogenesis by regulating sympathetic innervation of adipose tissue depots through hypothalamic nuclei, including the VMH. This demonstrates that CDK4 not only negatively regulates oxidative pathways, but also modulates the central regulation of metabolism through its action in the brain. Synopsis: CDK4 negatively regulates thermogenesis by suppressing oxidative pathways. This study reveals that CDK4 also modulates the systemic regulation of metabolism through its action in the hypothalamus. CDK4−/− mice exhibit increased energy expenditure and are cold resistant.BAT specific CDK4 deletion does not affect thermogenesis.CDK4−/− mice display increased sympathetic innervation of BAT and browning of subcutaneous WAT.VMH SF1 neuron specific CDK4−/− mice show increased adrenergic signaling and brown adipose tissue innervation.CDK4−/− mice exhibit increased sympathetic activity in the ventromedial hypothalamus. [ABSTRACT FROM AUTHOR]

Introduction. Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina) was examined in this study. The pancreas is both an exocrine and endocrine gland with autonomic and sensory innervation presented by the numerous nerve fibers and small agglomerations of nerve cells. Material and methods. Investigations were performed on 16 adult chinchillas of both sexes. The material was collected immediately after death of the animals. Histochemical methods: AChE and SPG were used, in addition to routine technique of single and double immunohistochemical (IHC) staining using whole mount specimens and freezing sections with a thickness of 8 to 12 µm. In the immunofluorescence staining, primary antibodies directed against markers used to identify cholinergic -- ChAT and VAChT, and adrenergic -- DbH and TH neurons. Secondary antibodies were coupled to Alexa Fluor 488 and Alexa Fluor 555 fluorophores. Results. Histochemical studies (AChE) revealed that chinchilla pancreatic cholinergic innervation consisted of ganglionic neurocytes and numerous nerve fibers. These structures are located in the parenchyma of the exocrine part of the organ in close proximity to blood vessels and are present within the walls of the pancreatic ducts and interstitial connective tissue. A delicate fiber network around the Langerhans islets was also observed. The most numerous cholinergic structures were found in the head and tail, and the least numbers were found in the body of the pancreas. The SPG method revealed that adrenergic fibers form a network in the adventitia of blood vessels, and individual fibers run throughout the pancreatic parenchyma. Moreover, adrenergic nerve fibers were observed around the ganglionic neurocytes. This innervation was similar in all parts of the investigated organ. IHC investigations allowed observations of both the cholinergic and adrenergic activities of autonomic nerve structures. Additionally, using ChAT/DbH double staining, colocalization of these substances was observed in the fibers of the pancreatic parenchyma that passed through the cholinergic ganglia. Colocalization of VAChT and TH was found in nerve fibers of the exocrine part, in the walls of blood vessels, and in individual nerve cells. Colocalization of ChAT/DbH and VAChT/TH was observed in the single nerve cells and in the small (2--3 cell) ganglia. ChAT- and DbH-immunopositive nerve fibers were found in the area of the islets of Langerhans. Conclusions. The results indicate a more intense cholinergic innervation of the chinchilla's pancreas, which is represented by both ganglia and nerve fibers, while adrenergic structures are mainly represented by fibers and only single neurocytes. This arrangement of the investigated structures in this species may imply a major role for hormonal control of exocrine secretion in rodents. [ABSTRACT FROM AUTHOR]

The effects of chronic hypotension on the density and intensity of fluorescence (after treatment with glyoxylic acid) of the plexus of adrenergic fibers in the wall of the saphenous artery and on the reinnervation of this vessel were studied in Wistar rats. Regional hypotension in the vascular bed of the hind part of the rats’ bodies was induced by stenosis of the abdominal part of the aorta distal to the renal arteries. After four weeks, the saphenous artery was denervated in one limb by resection of a segment of the femoral nerve. In the limb with the nerve lesion, chronic (6–7 weeks) hypotension led to a reduction in the intensity of nerve fiber fluorescence by 20% as compared with normotensive animals (controls), though the density of the nerve plexus did not change. Partial reinnervation of the vessel was observed 2–3 weeks after femoral nerve lesioning. Measures of reinnervation in normotensive and hypotensive rats were no different at two weeks, though at three weeks rats with hypotension showed more complete recovery of innervation. [ABSTRACT FROM AUTHOR]

Background: Cholangiopathies impair the balance between proliferation and apoptosis of cholangiocytes leading to the disappearance of bile ducts and liver failure. Taurocholic acid (TC) is essential for cholangiocyte proliferative and functional response to cholestasis. Bile acids and neurotransmitters co-operatively regulate the biological response of the biliary epithelium to cholestasis. Adrenergic denervation of the liver during cholestasis results in the damage of bile ducts. Aim: To verify whether TC feeding prevents the damage of the biliary tree induced by adrenergic denervation in the course of cholestasis. Methods: Rats subjected to bile duct ligation (BDL) and to adrenergic denervation were fed a TC-enriched diet, in the absence or presence of daily administration of the phosphatidyl-inositol-3-kinase (PI3K) inhibitor wortmannin for 1 week. Results: TC prevented the induction of cholangiocyte apoptosis induced by adrenergic denervation. TC also restored cholangiocyte proliferation and functional activity, reduced after adrenergic denervation. TC prevented AKT dephosphorylation induced by adrenergic denervation. The cytoprotective effects of TC were abolished by the simultaneous administration of wortmannin. TC administration prevents the damage of the biliary tree induced by the adrenergic denervation of the liver. These novel findings open novel perspectives in the understanding of the potential of bile acids especially in post-transplant liver disease. [ABSTRACT FROM AUTHOR]

Abstract: Pituitary adenylyl cyclase-activating polypeptide (PACAP), via its specific receptor pituitary adenylyl cyclase-activating polypeptide receptor 1 (PAC1-R), is known to have roles in neuromodulation and neuroprotection associated with glutamatergic and cholinergic neurotransmission, which, respectively, are believed to form the primary basis for afferent and efferent signaling in the organ of Corti. Previously, we identified transcripts for PACAP preprotein and multiple splice variants of its receptor, PAC1-R, in microdissected cochlear subfractions. In the present work, neural localizations of PACAP and PAC1-R within the organ of Corti and spiral ganglion were examined, defining sites of PACAP action. Immunolocalization of PACAP and PAC1-R in the organ of Corti and spiral ganglion was compared with immunolocalization of choline acetyltransferase (ChAT) and synaptophysin as efferent neuronal markers, and glutamate receptor 2/3 (GluR2/3) and neurofilament 200 as afferent neuronal markers, for each of the three cochlear turns. Brightfield microscopy giving morphological detail for individual immunolocalizations was followed by immunofluorescence detection of co-localizations. PACAP was found to be co-localized with ChAT in nerve fibers of the intraganglionic spiral bundle and beneath the inner and outer hair cells within the organ of Corti. Further, evidence was obtained that PACAP is expressed in type I afferent axons leaving the spiral ganglion en route to the auditory nerve, potentially serving as a neuromodulator in axonal terminals. In contrast to the efferent localization of PACAP within the organ of Corti, PAC1-R immunoreactivity was co-localized with afferent dendritic neuronal marker GluR2/3 in nerve fibers passing beneath and lateral to the inner hair cell and in fibers at supranuclear and basal sites on outer hair cells. Given the known association of PACAP with catecholaminergic neurotransmission in sympathoadrenal function, we also re-examined the issue of whether the organ of Corti receives adrenergic innervation. We now demonstrate the existence of nerve fibers within the organ of Corti which are immunoreactive for the adrenergic marker dopamine β-hydroxylase (DBH). DBH immunoreactivity was particularly prominent in nerve fibers both at the base and near the cuticular plate of outer hair cells of the apical turn, extending to the non-sensory Hensen’s cell region. Evidence was obtained for limited co-localization of DBH with PAC1-R and PACAP. In the process of this investigation, we obtained evidence that efferent and afferent nerve fibers, in addition to adrenergic nerve fibers, are present at supranuclear sites on outer hair cells and distributed within the non-sensory epithelium of the apical cochlear turn for rat, based upon immunoreactivity for the corresponding neuronal markers. Overall, PACAP is hypothesized to act within the organ of Corti as an efferent neuromodulator of afferent signaling via PAC1-R that is present on type I afferent dendrites, in position to afford protection from excitotoxicity. Additionally, PACAP/PAC1-R may modulate secretion of catecholamines from adrenergic terminals within the organ of Corti. [Copyright &y& Elsevier]

The innervation of the respiratory tract of amphibians is still poorly understood. Therefore, the respiratory tracts of the frogs Rana esculenta and Discoglossus pictus have been investigated in order to describe non-adrenergic non-cholinergic (NANC) and adrenergic innervation, and the localization of neuromediators that are possibly involved. Immunohistochemical staining of many bioactive substances was found in neuroepithelial cells of the buccopharynx, larynx, lung septa, nerves and neurons throughout the airway system. The findings indicate the occurrence of vasoactive intestinal peptide (VIP)-immunopositive nerve fibers in fibromuscular septa and the vasculature, nitrergic innervation of the large pulmonary veins showing a plexus of nNOS-immunopositive nerve fibers that also innervate the lung wall and the localization of neuronal nitric oxide synthase (nNOS) in neurons in the lung wall. In addition, laryngeal blood vessels and small arteries in the wall of septa that form capillary networks are supplied by enkephalin-immunopositive nerve terminals. We conclude that the airway system of the two frog species studied is innervated by a parasympathetic NANC system. Adrenergic innervation was also found that was immunostained for tyrosine hydroxylase. Adrenergic fibers were mainly present in muscles in septal edges, arteries present in septa and the wall of the lung. It is suggested that nNOS-positive and leu-enkephalin-positive neurons mediate vasodilation via the release of NO, but the nature of the NANC innervation remains obscure. Despite the many pharmacological studies of the lungs of amphibians, the physiological role of pulmonary autonomic innervation remains poorly understood. [Copyright &y& Elsevier]

1: There is a long-known hyper-responsiveness of vascular adrenergic transmission in the spontaneously hypertensive rat (SHR) that is uncovered specifically in the presence of cocaine and attributed to blockade of the neuronal monoamine transporter. We have now used the rat anococcygeus muscle to investigate whether this phenomenon is generic to sympathetic transmission to smooth muscle rather than a purely vascular phenomenon. We sought the origin of the effect by successively blocking the buffering effects of the neuronal monoamine transporter, prejunctional a2-adrenoceptors and NO from nitrergic nerves with desipramine (0.1?µM), rauwolscine (0.01?µM) and L-NG-nitro-arginine (100?µM). 2: In the presence of desipramine, contractile responses to electrical field stimulation but not to noradrenaline (1?nM-100?µM) were greater in SHR than in Wistar-Kyoto (WKY). Neither inhibition of prejunctional a2-adrenoceptors nor the blockade of neuronal nitric oxide synthase (nNOS) accounted for the differential enhancement of response in SHR. The enhanced effectiveness of motor neurotransmission in SHR becomes most apparent when all known major buffering mechanisms are removed. 3: When nitrergic responses were isolated pharmacologically (phentolamine 1?µM and guanethidine 30?µM; tone raised with carbachol 50?µM), they were not different between SHR and WKY. 4: Western blots showed that both nNOS and tyrosine hydroxylase are expressed to a similar extent in anococcygeus muscle from SHR and WKY, suggesting similar adrenergic and nitrergic innervations in the two strains. This suggests that enhanced motor transmission is due to increased transmitter release per varicosity rather than there being normal transmission from a greater number of sites. 5: We conclude that there is a generic enhancement of sympathetic transmission in SHR rather than this being a vascular phenomenon.British Journal of Pharmacology (2003) 140, 773-779. doi:10.1038/sj.bjp.0705480 [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate myocardial perfusion and adrenergic innervation in patients with intraventricular conduction disturbances and to detect any changes caused by alteration of the ventricular activation sequence as a result of right ventricular apical pacing. We studied 15 patients with right bundle branch block (RBBB) and left anterior fascicular block (LAFB), while 15 healthy individuals served as controls. All patients underwent planar and single-photon emission computed tomography (SPECT) myocardial imaging after intravenous infusion of 5mCi 123 I-metaiodobenzylguanidine (123 I-MIBG) and a SPECT thallium201 myocardial perfusion study before and 3 months after pacemaker implantation. The heart to mediastinum ratio was calculated during the 123 I-MIBG study in order to assess the global cardiac sympathetic activity and was significantly smaller in patients than in controls (P < 0.001). Patients with RBBB and LAFB revealed regional adrenergic innervation defects, mostly in the inferior and posterior walls. After a medium-term pacing period, a redistribution of 123 I-MIBG uptake was detected, with aggravation of adrenergic innervation defects in the apical and posterior walls and amelioration in septal and anterior walls. Five patients showed perfusion defects that remained unchanged after pacing. Two others displayed mild myocardial perfusion defects that did not exist before pacing. In conclusion, patients with RBBB and LAFB reveal global and regional disturbances of myocardial adrenergic innervation, which shows redistribution as a result of the altered propagation of the ventricular electrical activation. To a smaller degree these patients reveal myocardial perfusion disturbances in which pacing has a limited medium-term effect. (PACE 2003; 26:1202–1207). [ABSTRACT FROM AUTHOR]

We analysed the influence of aging on the acute effect of clenbuterol, a β2-adrenoceptor agonist, on the vasoconstrictor response induced by electrical field stimulation in mesenteric arteries from young and old spontaneously hypertensive rats (SHRs). Clenbuterol increased the contraction elicited by electrical field stimulation in arteries from both groups, and this was prevented by propranolol. NG-nitro-l-arginine methyl ester (l-NAME) also increased the electrical field stimulation-elicited contractions in arteries from both age groups. However, pretreatment with capsaicin increased the electrical field stimulation-induced contractions in young SHRs, but did not modify it in old SHRs. In segments from young SHRs, the treatment with the calcitonin gene-related peptide (CGRP) receptor antagonist, CGRP-(8–37), induced an increase in the electrical field stimulation-induced vasoconstrictor response that was not modified by the subsequent addition of capsaicin. Addition of clenbuterol to l-NAME-treated segments from both groups further increased the response to electrical field stimulation. In segments from young SHRs, clenbuterol failed to increase the electrical field stimulation-induced response in the capsaicin-treated segments, but the response was increased by the subsequent addition of l-NAME. The addition of l-NAME to the clenbuterol-treated segments from old SHRs did not modify the enhanced electrical field stimulation response. Electrical field stimulation induced a similar tritium release in arteries from young and old SHRs preincubated with [3H]noradrenaline. In arteries from young SHRs, isoproterenol increased this release and the increase was abolished by propranolol. Clenbuterol increased the stimulated tritium overflow and exogenous noradrenaline response only in segments from old SHRs, and both effects were abolished by propranolol. To summarize and conclude, clenbuterol increased the electrical field stimulation-induced contraction in segments from both age groups. In young SHRs, clenbuterol seems to inhibit CGRP release, while in old SHRs, it increases the release of and response to noradrenaline and decreases neuronal nitric oxide (NO) release. [Copyright &y& Elsevier]

Early postoperative complications after small bowel transplantation (SBT) are likely mediated, at least in part, by dysmotility caused by the obligate disruption of extrinsic and enteric nerves in the graft. Adrenergic hypersensitivity of gut smooth muscle has been observed in some (but not all) segments of intestine in various experimental models of SBT, highlighting regional and species variability in response to denervation. Little is known about changes in canine longitudinal muscle after extrinsic denervation. Six dogs each underwent either complete extrinsic denervation of the jejunoileum or a control operation (transection and reanastomosis of the proximal jejunum and distal ileum). In vitro contractile response of longitudinal muscle strips to norepinephrine was evaluated at the time of the operation, and 2 weeks and 8 weeks later. After extrinsic denervation, the jejunal response to norepinephrine was preserved at all time points; however, the ileum displayed a decreased sensitivity to norepinephrine, an effect unmasked after intramural neural blockade with tetrodotoxin. These data support a potential for neurally mediated dysmotility after SBT and reinforce the differences in responses to extrinsic denervation between species, as well as differences within different regions and between anatomic segments of small intestine in the same species. ( J Gastrointest Surg 2002;6:418–425.) [ABSTRACT FROM AUTHOR]

The contractile effects of α-adrenoceptor agonists and field electrical stimulation were investigated pharmacologically in canine isolated tracheobronchial lymph nodes. Addition of noradrenaline (NA), phenylephrine (Phe) and UK14,304 caused dose-related contractions of the isolated lymph nodes. Pretreatment with prazosin (3×10−9, 3×10−8 and 3×10−7 M) shifted the concentration–response curve for phenylephrine to the right, whereas yohimbine (3×10−7 M) did not affect the contractile responses to phenylephrine. On the other hand, the concentration–response curve for UK14,304 shifted to the right by treatment with yohimbine (3×10−9, 3×10−8 and 3×10−7 M) but not by prazosin (3×10−7 M). Field electrical stimulation (25 V, 0.7 ms, 16 Hz) produced contractile responses of the lymph nodes. The electrical stimulation-induced contractions were completely reduced by pretreatment with tetrodotoxin (TTX) (3×10−7 M) or bretylium (10−6 M). Furthermore, phentolamine (10−8, 10−7 and 10−6 M), prazosin (3×10−9 and 3×10−8 M) and yohimbine (3×10−8 and 3×10−7 M) significantly reduced the electrical stimulation-induced contractions in the preparations. The present findings suggest that there are both α1- and α2-adrenoceptors located on the smooth muscle cells in canine tracheobronchial lymph nodes, and that the adrenoceptors-mediated excitatory mechanisms of adrenergic innervation exist in the lymph nodes. [Copyright &y& Elsevier]

The normal depression of plasma insulin concentration during exercise has been ascribed to adrenergic inhibition of insulin release and the role of humoral catecholamines in this hormonal adjustment has repeatedly been stressed. In the present study this contention has been investigated in 6 bilaterally adrenalectomized patients and in 6 sex- and age-matched controls who undertook exercise on an ergometer until they were exhausted. No differences were observed in any cardiovascular or metabolic adjustments between the two groups during strenous exercise. Mean plasma insulin concentration fell by about 50% in both groups. Phentolamine effectively abolished the fall in plasma insulin concentration during exercise in 2 adrenalectomized patients. The results suggest that the adrenergic nerves that supply the B-cells have a functional role in man during exercise. [ABSTRACT FROM AUTHOR]

The postnatal development of the adrenergic innervation pattern in the rat portal vein has been studied with the histochemical fluorescence method of Hillarp and Falck. Stretch preparations and transverse freeze-dried sections of intact portal veins were studied from rats during the first 5 weeks of life and from adult rats. Orientation of undifferentiated smooth muscle cells into two layers was observed at 4 days of age. Dominance of the thick outer longitudinal muscle layer was apparent at two weeks of age. A terminal adrenergic nerve plexus with some varicosities was restricted outside the media at the end of the first week. Ingrowth of penetrating non-terminal adrenergic nerve fibers through the longitudinal muscle layer occurred during the second week of age when the main terminal nerve plexus was developing between the two muscle layers. After 3 weeks of age the adult pattern of a two-dimensional adrenergic plexus between the muscle was established. In the adult rat pharmacological treatment with nialamide and noradrenaline revealed the thin, penetrating non-terminal adrenergic nerve fibers in the longitudinal muscle layer which were poorly visible otherwise. The present observations strongly indicate that the main adrenergic plexus between the two muscle layers emanates directly from the outer axonal plexus. These findings are discussed regarding possible trophic interactions between ingrowing sympathetic adrenergic vasomotor nerves and maturing vascular smooth muscle. [ABSTRACT FROM AUTHOR]

The innervation of the male genital tract and kidney in three anuran species was studied by the fluorescence histochemical method of Falck-Hillarp for the demonstration of monoamines whose identity was secured by thin-layer chromatography, and by electron microscopy including administration of 5- or 6-hydroxydopamine (5- and 6-OHDA). The genital tract comprises testis, intra- and extratesticular and intrarenal seminal efferent ducts, Bidder's canal, renal dorsal transverse ducts, and ureter. In addition-depending on the species studied-renal corpuscles and the various portions of uriniferous tubules may be involved in sperm transport. [ABSTRACT FROM AUTHOR]

The development of noradrenergic innervation of rat liver was studied with a polyclonal antiserum against noradrenaline. Nerves are first seen in the larger portal vessels at day 1 after birth and reach their final distribution at 5 days after birth i.e. at the same time as the establishment of the acinar architecture and the heterogeneous distribution of NH-metabolizing enzymes. The latter distribution of nerves is already seen at birth in the liver of the closely related but precocial spiny mouse. This shows that the onset of extrinsic sympathetic innervation is regulated by the developmental stage of the animal rather than by adaptation to extrauterine life. Chemical sympathectomy at birth with 6-hydroxydopamine did not eliminate the developmental appearance of heterogeneous distributions of NH-metabolizing enzymes. [ABSTRACT FROM AUTHOR]

A comparative histochemical and clinical study concerning the state of the intrinsic adrenergic innervation of the human atrial myocardium was carried out, using the glyoxylic acid-induced fluorescence histochemical method. Specimens from the right auricular appendage were obtained during open-heart surgery from patients suffering from 1. ischaemic heart disease (IHD), 2. atrial septal defect of the secundum type (ASD), and 3. left-sided univalvular or multivalvular heart disease (VHD) with or without congestive heart failure (CHF) experienced prior to surgery. In the IHD group the densities of both the perivascular and the 'free' myocardial adrenergic nerve net were greater than in the ASD group and especially in the VHD/ CHF group. Secondly, the intensity of fluorescence of the adrenergic structures was generally higher in the IHD group than that in the VHD/CHF group. Further, the average size of the varicosities, the number of varicosities per given length of axon, and the proportional share of the large varicosities were greater in the IHD group than in the ASD and VHD/CHF groups. The difference between the IHD and ASD groups was not great but was obvious in any case. In some patients with VHD/CHF fluorescing axons were observed only occasionally, and the tiny varicosities exhibited a hardly discernible fluorescence. Thus the amount of noradrenaline (NA) in the adrenergic fibres in the IHD group seems to be higher than in the ASD and especially VHD/CHF groups. The high level of NA in the IHD group is assumed to constitute a contributory factor in both intracellular metabolic changes and the systemic changes typical of myocardial ischaemia and infarction. In one patient with IHD and in six patients with VHD/CHF with significantly higher heart volume (mean±SD) compared with the rest of the patients ( P<0.001), huge local axonal accumulations of NA in the form of 'droplet fibres' were found. These enlarged, bulging adrenergic axons are assumed to be a consequence of mechanical trauma with stretching or disruption of the axons due to myodegenerative processes. It is further assumed that these 'droplet fibres' are relatively common in those patients with diseased myocardium. They may constitute an extra contributory factor to the tendency to arrhythmias so typical of patients of this kind, by increasing the excitability of non-automatic tissue. [ABSTRACT FROM AUTHOR]

We study the esophagus of Podarcis hispanica through different methods to clarify the structure and affinities of its wall innervation. The acetylcholinesterase method reveals cholinesterase activity in two submucosal nervous plexuses, with an increasing degree of structural complexity in the reptilian esophagus, compared with amphibians. Noradrenergic innervation, detected through fluorescence induced by formol, widely spreads its network in both the myenteric and submucosal plexuses (around the blood vessels in the external submucosal plexus, and to the glandular lamina propria in the inner submucosal plexus). Immunohistochemistry for vasoactive intestinal peptide shows a widespread innervation, with neurons clustered in ganglia and also scattered through the VIPergic network, only at the myenteric plexus. Immunohistochemistry for substance P shows a rich innervation along the entire wall of the esophagus, more concentrated in its caudal region, around the blood vessels. Electron microscopy shows the enteric neuronal ultrastructure and its relationship with the esophagus wall. [ABSTRACT FROM AUTHOR]

The fine structure of the pineal gland and the pineal innervation in the tree shrew were studied by electron microscopy and glyoxylic acid-induced fluorescence microscopy respectively. The parenchymal cells consist of pinealocytes, glial cells and pigment-containing cells. The pinealocytes are characterized by the presence of granular vesicles, synaptic ribbons, electron-dense bodies and small profiles of rER with dilated cisternae. Glial cells contain light cytoplasmic bodies, lipofuscin granules, bundles of microfilaments, and elongate profiles of rER with flattened cisternae which are often stacked together with light cytoplasmic bodies; the pigment-containing cells are unique in possessing giant pigment granules in the cytoplasm. The pinealocyte/glial cell/pigment cell in tree shrew pineals may be the same cell line of parenchymal cells at different ontogenetic stages. Pigment-containing cells contain pigment granules as a prominent cytoplasmic inclusion, suggesting they are senscent in secretory function. Both pinealocytes and glial cells contain structures suggesting secretory function such as welldeveloped Golgi complex and granular vesicles. The antigonadotrophic substances may be stored in granular vesicles. The present ultrastructural study supports the conclusion that tree shrew pineal organ is an endocrine gland which is heavily innervated by adrenergic nerves and possibly by cholinergic nerves. [ABSTRACT FROM AUTHOR]

Right atrial biopsis from rat and human hearts were studied using combined methods for the demonstration of glyoxylic acid-induced fluorescence (GIF) of catecholamines and acetylcholinesterase (AChE) reactions in the same specimens. In specimens from the rat heart, the GIF and AChE reactions were performed either simultaneously or consccutively. In biopsies of the human right atrium, obstained at right atria cannulation during open-heart surgery, the reactions were performed consecutively. In was found that in both rat and human atria the adrenergic nerves and AChE reactive nerves, which are probably cholinergic, run partly separately and partly together. In the rat atrial specimens, close relations between adrenergic nerves and clusters of AChE reactive cells were observed. In addition, clusters of fluorescent cells were observed in the vicinity of AChE reative nerve bundles. This indicates that there may be several possible means of peripheral interaction between the intrinsic adrenergic and cholinergic systems of the rat heart. [ABSTRACT FROM AUTHOR]

A fluorescence histochemical study was performed to describe the adrenergic innervation of the coronary arteries and the left ventricular myocardium in the pig. Large bundles of adrenergic nerve fibres were almost exclusively found running along the large coronary arteries. The arteries usually show a dense innervation of the vessel wall, evenly distributed throughout the adventitia in the larger arteries and more concentrated to the adventitia-medial border in the smaller arteries and arterioles. Most parts of the left ventricular myocardium showed a dense adrenergic innervation, however, a moderate dense and in some areas even sparse innervation was observed towards the apex of the left ventricle. Following 10 or 20 min of ischemia a small reduction in fluorescence intensity was observed in 2 out of 6 hearts. In 4 of the hearts other changes of the appearance of the adrenergic terminals were found, e.g., an unsharp, spread-out or interrupted appearance. [ABSTRACT FROM AUTHOR]

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Mesenteric efferent lymph was collected from anaesthetized sheep. Lymph flow rate and leucocyte content (> 95% lymphocytes) were measured under control conditions and during stimulation of the left greater splanchnic nerve. During the first 5 min of nerve stimulation at 4 Hz lymph flow was increased by 128±57% and lymph white cell count by 44±15% ( P<0.05, n= 8 in both cases). This produced an overall increase in the white cell output of 228±151% ( P<0.05, n=8). The response was repeatable but short lived, with no significant differences from control being observed after the first 5 min of stimulation. There was a rise in the red cell count in arterial blood during nerve stimulation (from 3.21±0.24 · 10 l to 4.48±0.22 · 10 l, P<0.05, n=9) but no statistically significant changes in the white cell count or percentage of lymphocytes. The increase in lymph white cell output could be mimicked by intravenous injection of noradrenaline while phentolamine blocked the nerve-induced increases in both lymph flow and white cell concentration. The possible mechanisms and immunological consequences of this α-adrenoceptormediated increase in lymphocyte traffic are discussed. [ABSTRACT FROM AUTHOR]

Galanin-containing nerve fibers have previously been observed in the human, dog, and pig pancreas. Whether the mouse and rat pancreas also contain galanin nerve fibers has been a matter of debate. Therefore, we examined the distribution of galanin in the mouse and the rat pancreas. Further, the possible localization of galanin to adrenergic nerves was studied using sequential immunostaining for galanin and tyrosine hydroxylase (TH). In the mouse pancreas, numerous galanin-immunoreactive (GIR) nerve fibers occurred around blood vessels. They were less numerous in the exocrine parenchyma and in association with the islets. In contrast, in the rat pancreas, only a few GIR nerves were found. They were located around blood vessels and scattered in the exocrine parenchyma. Occasionally, GIR nerves were also observed in the islets. There was a dense distribution of TH-immunoreactive fibers in both the mouse and the rat pancreas. Sequential immunostaining revealed co-localization of galanin and TH immunoreactivity in nerve fibers in both the mouse and the rat pancreas. Following chemical sympathectomy using 6-hydroxydopamine (6-OHDA), not all GIR nerves disappeared. In the mouse pancreas a remaining population of galanin nerves was found around blood vessels, and occasionally in the islets. In the rat pancreas, a few GIR nerves were seen also after chemical sympathectomy. We conclude that intrapancreatic GIR nerves also occur in the mouse and the rat. These findings suggest that many of the GIR nerves are adrenergic but that non-adrenergic, possibly intrinsic or sensory GIR nerves exist as well in both the mouse and the rat pancreas. [ABSTRACT FROM AUTHOR]

The development of the intraovarian adrenergic nervous system was investigated in the guinea-pig by use of chemical determination of catecholamines with high performance liquid chromatography (HPLC) and with the formaldehyde-induced fluorescence method for visualization of adrenergic nerves (Falck-Hillarp technique). Ovaries from fetuses (39-40, 45-50, 55-57, 60-63 days of gestation) and young animals (1, 2, 3, 7, 14, 30, 40-45 days of age) were included in the study. The noradrenaline concentration was low in the ovaries from the youngest fetuses but increased with age, reaching a maximum level at 2 days post partum. A marked decrease in noradrenaline concentration from the second to the third day of life was found as a consequence of the rapid increase in the ovarian weight during this time. A similar decrease in ovarian noradrenaline concentration after a period of rapid ovarian growth was noted at 30 days of age. Measurable amounts of adrenaline were found in the ovary only in the fetal stages; the highest concentration (0.73 μg) was detected at 55-57 days of gestation. [ABSTRACT FROM AUTHOR]

The innervation of the chicken ovary was investigated with special emphasis on adrenergic nerves in the follicular wall. Quantitative determinations of catecholamines (CA) by high-performance liquid chromatography and electrochemical detection (hplc-ed) revealed 15.4±3.3 ng/mg protein of norepinephrine (NE) and 3.14 ng/mg protein of epinephrine (E), with even larger amounts in the cranial part of the ovary close to the adrenal gland. Serial sections that had been processed for the visualisation of aminergic nerves (Falck-Hillarp- or glyoxylic acid technique) showed CA localized in nerve-fibre bundles; cell bodies of chromaffin and sympathetic neurons were only found at the ovarianadrenal junction suggesting that ovarian nerves stored considerable quantities of E. An antiserum against bovine phenylethanolamine N-methyltransferase (PNMT, the E-synthesizing enzyme) produced no immunostaining in chicken ovary or adrenal gland, due to a lack of crossreactivity between the antiserum and chicken PNMT. Serial sections processed alternately for the visualisation of aminergic nerves and myosin (from chicken gizzard) immunoreactivity revealed a scarce nerve supply of contractile cells in the theca externa compared to an extraordinarily dense innervation of the endocrine interstitial tissue of the theca interna. This distribution pattern of nerve fibres in the follicular wall was confirmed by electron microscopy in ovarian tissue that had been pretreated with 5- or 6-hydroxydopamine (OHDA). More than 90% of the terminal axons were specifically labeled by these false adrenergic transmitters. Many of these terminals were seen in close contact (20 nm) with steroidogenic cells suggesting a neuromodulatory function of CA in hormone synthesis and/or release. It is yet unclear whether E and NE are stored in separate or identical axon moieties and within the same organelles. Choline acetyltransferase activity, which was taken as a measure for a cholinergic nerve component in the ovary, amounted to only 7% of its adrenal activity. It is suggested that the chicken ovary may serve as an excellent model to investigate the modulatory role of nerves in the endocrine function of the ovary. [ABSTRACT FROM AUTHOR]

Morphological changes in the adrenergic innervation of pancreatic islets after chemical sympathectomy by use of 6-hydroxydopamine and the influence of the sympatho-adrenal system on insulin secretion were investigated in the mouse and rat. Fluorescence histochemistry revealed a clear-cut reduction in the number of adrenergic nerve fibers in the pancreatic islets 2 days after administration of 6-hydroxydopamine; the reduction was more pronounced in the rat than in the mouse. In the rat, a partial regeneration was seen after 6 weeks. In the pancreas of the mouse, after administration of 6-hydroxydopamine, a severe damage of unmyelinated nerve fibers was revealed electron microscopically. However, no ultrastructural or immunohistochemical alterations could be demonstrated in the endocrine cells of the islets. 6-Hydroxydopamine induced a depression of basal plasma insulin concentrations in mice and an elevation in rats. Adrenalectomy depressed basal plasma insulin levels in mice. The α-adrenoceptor antagonist phentolamine enhanced insulin secretion in normal mice. The secretory response of insulin to phentolamine was diminished by chemical sympathectomy and almost abolished by adrenalectomy or the combination of chemical sympathectomy and adrenalectomy. Thus, the effect of phentolamine is probably mediated by liberated catecholamines. It is concluded that basal insulin secretion is partially regulated by the sympatho-adrenal system and that species differences exist in this respect. In addition, the results suggest that endogenous catecholamines have the ability to promote insulin secretion. [ABSTRACT FROM AUTHOR]

The autonomic innervation of the ovary was studied in 12 mammalian species utilizing the cholinesterase method in combination with pseudocholinesterase inhibition for the cholinergic component, and glyoxylic acid histochemistry together with fluorometric determination of noradrenaline for the adrenergic component. Ovaries from cow, sheep, cat, and guinea pig were very richly supplied with adrenergic nerves in the cortical stroma, particularly enclosing follicles in various stages of development. In the follicular wall the nerve terminals were located in the theca externa, where they ran parallel to the follicular surface. Numerous adrenergic terminals also surrounded ovarian blood vessels. The adrenergic innervation was of intermediary density in the human ovary and in the pig, dog, cat, and opossum. Ovaries from rabbit, mouse and hamster had a sparse adrenergic nerve supply. The amount of intraovarian adrenergic nerves agreed well with the tissue concentration of noradrenaline in the various species. The cholinergic innervation was generally less well developed, but had the same distribution as the adrenergic system around blood vessels and in the ovarian stroma, including follicular walls. [ABSTRACT FROM AUTHOR]

Neuroepithelial bodies (NEB) were identified in the lung of Bufo marinus. The characteristics of the cells and their innervation were studied with electron and fluorescence microscopy before and after close vagosympathetic denervation. The bodies consist of low columnar cells which rest on the epithelial basal lamina. The majority of the cells do not reach the lumen of the lung (basal cells); the few which do (apical cells) are bordered by microvilli and possess a single cilium. The neuroepithelial cell cytoplasm contains a variety of organelles the most characteristic of which are dense cored vesicles. Microspectrofluorometry and electron microscopic cytochemistry indicate significant quantities of 5-hydroxytryptamine in these cells. The neuroepithelial bodies could be divided into three groups on the basis of their innervation: 1) About 60% of the NEBs are innervated solely by nerve fibres containing agranular vesicles which form reciprocal synapses; 2) about 20% are innervated solely by adrenergic nerve fibres which form distinct synaptic contacts; and 3) the remaining 20% are innervated by both types of nerve fibres. It is proposed that the NEBs are receptors monitoring intrapulmonary P and so leading to modulation of activity in afferent nerve fibres (type containing agranular vesicles). The presence of NEBs solely with an adrenergic (efferent) innervation poses a problem with this interpretation. [ABSTRACT FROM AUTHOR]

An investigation of the stereospecificity of β-adrenergic insulin release, its relation to α-adrenergic blockade and the adrenergic innervation of the pancreatic islets was performed in the mouse. It was observed that in vivo β-adrenergic stimulation of insulin release by isopropylnoradrenaline was stereospecific for the L-stereoisomer and selectively blocked by the L-isomer of the β-adrenergic antagonist L-propranolol. D-propranolol had no effect. Pretreatment of mice with a dose of D-isopropylnoradrenaline devoid of insulin releasing activity, slightly increased the subsequent insulin response to a halfmaximal dose of L-isopropylnoradrenaline. Basal insulin secretion was blocked by L-propranolol ( β-adrenergic blockade) and increased by phentolamine ( α-adrenergic blockade). A β-blocked insulin response to L-isopropyl-noradrenaline could be overcome by α-adrenergic blockade depending on the dose of the β-agonist, suggesting a close association between the adrenergic receptors. The adrenergic innervation of the islet cells was studied by electron microscopic autoradiography after injection of H-L-noradrenaline. It was observed that labelled adrenergic nerve terminals were associated with both A(D-), A and B-cells. The nerves were mainly distributed in the periphery of the islets either as single axons or as bundles. The majority of the terminals were associated with A-cells, the most frequent cell type in the islet periphery. However, in all islets examined terminals were found close to B-cells. Adrenergic terminals often caused indentations in the contour of an islet cell and were separated from the islet cell membrane only by a narrow intercellular space, about 20 nm in width. It is concluded that the islet cells of the mouse are equipped with the morphological substrate for direct adrenergic regulation. Further it is suggested that the B-cell is supplied with L-stereospecific β-adrenergic receptors and that the α- and β-adrenergic receptors are at least partially interrelated. [ABSTRACT FROM AUTHOR]

The development of noradrenergic innervation was studied in the mouse heart using fluorescence histochemistry. Following incubation of hearts with α-methylnoradrenaline fluorescent nerve fibres were seen as early as 13 days in utero. It is suggested that the neuronal uptake mechanism for noradrenaline is functional at an early stage. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Oto-rhino-laryngology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For the purpose of elucidating the motility, particularly the mechanism of contraction of the gallbladder, we classified gallbladders isolated surgically into three groups for a study. That is, the three groups comprised Group I of 40 cases of cholelithiasis with good contraction, Group II of 10 cases of cholelithiasis with poor contraction and Group III of 10 cases of cholelithiasis after gastrectomy for a total of 60 cases. Using gallbladders of these cases, we started with a fundamental study on the autonomic nervous action by the fluorescence histochemical method of Flack and Hillarp and obtained results as follows. Similar results were obtained for Group I and Group II; the gallbladder was subjected to adrenergic innervation and cholinergic innervation, and there was a clear localized difference between true-cholinesterase and pseudo-cholinesterase of the cholinergic nerve. In Group III, proliferation of adrenergic nerve was observed compared with Groups I and II, while disappearance of cholinergic nerve was seen. The gallbladder of Group HI showed slight contraction with cholecystokinin, but it was not blocked with atropine. [ABSTRACT FROM AUTHOR]

The effect of distension on adrenergic innervation was investigated in the rat urinary bladder. Bladders were distended for 3 h by forced diuresis and ballon obstruction, and specimens were taken from the bladder dome, body and neck for the demonstration of glyoxylic acid-induced fluorescence of catecholamines. Depletion of catecholamines started after 10 h and was almost complete after 2 days. The fluorescence had recovered part way after 5-7 days and was practically normal after 21 days. Small, intensely fluorescent (SIF) cells in the ganglia continued to leak catecholamines throughout the 21-day study period. The primary clinical success of distension therapy for the treatment of unstable bladder may be at least partly due to a reversible disturbance in the function of the adrenergic nerves, which have an excitatory alpha-adrenergic dominance in such cases, but the persistent leakage from SIF cells raises the question of whether distension causes prolonged disturbances in bladder function. [ABSTRACT FROM AUTHOR]

Innervation of the external urethral sphincter (EUS) was studied in male human subjects. In the region of EUS at the distal end of prostatic urethra, a large axon bundle surrounded by perineurium was evident in the intramural connective tissue gap. Because of the presence of dense core vesicles, the small nonmyelinated axon profiles in the bundle were considered to be adrenergic. After ramifications to smooth musculature, the axons were traced to the EUS. In the EUS, axon bundles containing many nonmyelinated axons were recognized as a sole autonomic nerve among the striated muscle cells. A single or at most two or three axons were surrounded by a Schwann cell, and some possessed dense core vesicles which suggested an adrenergic function. These autonomic adrenergic nerve ends formed surface junctions with the striated muscle of EUS. The clinical relevance of these data are discussed. [ABSTRACT FROM AUTHOR]

The human tunica dartos has been investigated by light, fluorescence and electron microscopy. It consists of solid bundles of smooth musculature in the subcutis, and small bundles or single muscle cells in the corium. Smooth muscle bundles in both the subcutis and corium are composed of ordinary smooth muscle cells. Single muscle cells of the corium resemble myofibroblasts showing features of fibrocytes and smooth muscle cells. As revealed in single smooth muscle cells, each cell appears to be surrounded by a coat of interweaving microfilaments which penetrate neighbouring bundles of collagen fibres and show inclusions of elastin. Part of the microfilaments extend into the specialized subepithelial connective tissue layer and may insert at the basement membrane. Only ordinary smooth muscle cells have an adrenergic innervation, which indicates their involvement in sympathetic thermoregulatory reflexes. [ABSTRACT FROM AUTHOR]

The intra- and extrafetal portions of the umbilical vessels in the guinea-pig and the umbilical cord of man, mouse and rabbit have been investigated by means of the Falck-Hillarp method for the fluorescence microscopical demonstration of catecholamines. The umbilical cord was found to be devoid of nerves in all species investigated. Adrenergic nerves are present only in the immediate vicinity of the umbilicus. The intrafetal portions of the umbilical artery and umbilical vein receive adrenergic nerves, the distribution pattern of which is different for each vessel. In the guinea-pig the ductus venosus is an intrahepatic branch of the vena umbilicalis. No adrenergically innervated sphincter has been detected in the initial segment of the ductus venosus. Regional variations in the pattern of innervation of the intrafetal portion of the umbilical vein are paralleled by regional differences in the construction pattern of the vessel's wall. Regional differences in the noradrenaline concentration (measured by fluorometry) which correspond to the fluorescence microscopical findings have been detected in umbilical vessels: low noradrenaline content of the umbilical cord, high concentrations in the intrafetal sections of the umbilical vessels. The noradrenaline concentration of the guinea-pig umbilical artery is three times that of the umbilical vein. [ABSTRACT FROM AUTHOR]

Fluorescence histochemistry has been used to study the effects of 6-hydroxydopamine (6-OHDA) (100 mg/kg injected into the dorsal lymph sac) on adrenaline-containing nerves in the large intestine, mesentery, lung, bladder and heart atria of the toad Bufo marinus. A gradual decrease both in fluorescence intensity and in number of detectable fibres during the first 4 hours after 6-OHDA was accompanied by a build-up of fluorescence in the nonterminal regions. These phenomena have been discussed in relation to the time course of the degeneration produced by 6-OHDA in noradrenergic nerves of higher vertebrates. Almost complete 'chemical sympathectomy' was seen after one day, and it was not till 13 days that regenerating nerve fibres were seen in any organ. In the large intestine, however, re-innervation was slower, being first noted after 39 days. The time course of regeneration has been compared with that following sympathectomy in various mammalian organs. [ABSTRACT FROM AUTHOR]

The distribution of adrenergic terminals to the anterior eye segment of humans, Cynomolgue monkeys, squirrel monkeys, owl monkeys, Cebus monkeys, vervets, tamarins, and baboons has been investigated. The cornea is normally devoid of adrenergic terminals, except in a plexus near the limbus. The trabecular meshwork contains varying numbers of adrenergic terminals: usually none in Cynomolgus monkeys, patas monkeys, vervets, and humans, although fibres have very rarely been observed in Cynomolgus monkeys, vervets, and humans; a few in owl monkeys, squirrel monkeys, and tamarins; and moderate numbers in Cebus monkeys and baboons. From the evidence, however, it seems premature to presume an adrenergic innervation of the trabecular mechanism regulating the outflow resistance. The dilatator pupillae is regularly supplied with numerous adrenergic terminals and in the iris stroma there is probably an adrenergic innervation of the melanophores. The sphincter pupillae regularly contains adrenergic terminals with notable species differences; most fibres occur in baboons and fewest in humans, with the remaining species forming a middle class. The ciliary processes in all species contain a moderate number of adrenergic terminals, presumably primarily associated with the epithelium. Intraepithelial adrenergic terminals have been observed on the pars plana of the ciliary body of humans, Cebus monkeys, vervets, baboons, and patas monkeys. The ciliary muscle of baboons and Cynomolgus monkeys contains numerous adrenergic terminals. Moderate numbers occur in Cebus monkeys and vervets, and still less in (in falling order) tamarins, squirrel monkeys, humans, and patas monkeys. [ABSTRACT FROM AUTHOR]

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Copyright of Zeitschrift Für Zellforschung und Mikroskopische Anatomie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adrenergic innervation of the subdiaphragmatic digestive tract of the rabbit, the rat and the guinea-pig, has been studied by means of the histochemical technique of Falck and Hillarp. Auerbach's and Meissner's plexuses are richly supplied by adrenergic fibres both in the ganglia and in the connecting tracts. The distribution of adrenergic fibres appears fairly uniform within the myenteric ganglia of the different subdivisions. No adrenergic intramural neurons are found except in Auerbach's plexus of the proximal colon of the guinea-pig where particularly tightly packed clusters of pericellular baskets are also found. Adrenergic fibres are present within the circular muscle layer of all regions, and in the taeniae of the caecum of the guinea-pig. In the cardiac and the anal sphincters there is an exceedingly dense innervation of longitudinal and circular muscle. The glands of the mucous coat in the different parts of the gut are richly supplied by adrenergic nerves. There is a dense innervation of intestinal arteries. It is suggested that postganglionic adrenergic axons have a direct action on the muscle and that they indirectly affect the muscle by an action on intramural ganglia. [ABSTRACT FROM AUTHOR]