Distribution of galanin immunoreactivity in the respiratory tract of pig, guinea pig, rat, and dog.

Galanin, a newly discovered peptide isolated from porcine intestine, is known to cause contraction in rat smooth muscle preparations and to induce hyperglycaemia in dogs. By the use of radioimmunoassay and immunohistochemical techniques the concentration and distribution of galanin immunoreactivity were determined in several areas of the respiratory tract of five dogs, five guinea pigs, five rats, and two pigs. Antibodies were raised in rabbits to whole unconjugated natural porcine galanin. The highest galanin concentrations were found in the bronchus and the trachea of the dog, guinea pig, rat (2 pmol/g in each case), and pig (less than 1 pmol/g). The lowest galanin concentrations were found in the lung parenchyma. Gel chromatographic analysis in the pig showed one molecular form of galanin coeluting with the porcine galanin standard. By means of the indirect immunofluorescence technique on sections of tissues fixed in benzoquinone solution, galanin was found to be confined to nerve fibres in different regions of the respiratory tract. In the nasal mucosa of the pig nerve fibres containing galanin were distributed around seromucous glands and blood vessels and beneath the epithelium. In the trachea, bronchus, and major intrapulmonary airways of the pig, dog, and guinea pig galanin immunoreactive fibres were detected predominantly in smooth muscle, as well as around seromucous glands and in the adventitia of blood vessels. Rarely, galanin immunoreactive nerve fibres were found in the lung parenchyma. A few galanin immunoreactive ganglion cells also containing vasoactive intestinal polypeptide were found in the adventitia of the tracheobronchial wall of the pig and dog. The distribution of galanin suggests that it may have some influence on airway, vascular, and secretory functions in the mammalian respiratory tract.     

Regulatory peptides in the respiratory tract of Macaca fascicularis.

The quantitative distribution and localisation of seven regulatory peptides (vasoactive intestinal peptide (VIP), peptide histidine methionine (PHM), calcitonin gene related peptide (CGRP), galanin, substance P, neuropeptide tyrosine (Y), and bombesin like peptides) were determined by radioimmunoassay and immunocytochemistry in six different regions of the respiratory tract of the cynomolgus monkey, Macaca fascicularis. In general, peptide concentrations were higher in the airways than in lung tissue itself. VIP and PHM were found in greatest abundance and in equimolar concentrations. Concentrations of substance P, neuropeptide Y, and bombesin were substantially lower. Immunocytochemistry localised all the peptides to nerve fibres, whose density generally paralleled the tissue concentrations by radioimmunoassay except in the case of bombesin, which was not detected. VIP, PHM, and galanin were mostly associated with glands of trachea and bronchus and with blood vessels and smooth muscle; CGRP and substance P were found principally beneath airway epithelium and around smooth muscle fibres and blood vessels; neuropeptide Y was found around blood vessels and seromucous glands only. The pattern of peptide distribution in the Macaca fascicularis respiratory tract is similar to that previously reported in human postmortem material, suggesting that the cynomolgus monkey may be a useful model for examining the pathophysiological role of peptides in human respiratory disease.     

Immunohistochemical Localization of Neuropeptide Y in Nerves of the Male Genital Tract of the Photoperiodically Responsive Djungarian Hamster, Phodopus Sungoras/Immunhistochemische Lokalisation von Neuropeptid Y in Nerven der männlichen Genitalorgane des photoperiodisch sensiblen Djungarischen Zwerghamsters, Phodopus sungorus

Neuropeptide Y (NPY) was demonstrated by immunohistochemistry in nerves of the male genital tract of Phodopus sungorus at long (LD 16:8) und short (LD 8:16) photoperiods. No immunoreactive nerve fibres could be demonstrated in the testis, caput and corpus epididymidis and the ventral prostate gland. Dense networks of NPY-containing nerve fibers were demonstrated in the smooth muscle layer of the sperm-transporting duct, beginning in the cauda epididymidis with increasing density towards the distal part of the ductus deferens, and in the smooth muscle layer of the seminal vesicles. At short photoperiods, the density of the NPY-containing nerve plexus decreased only in the smooth muscle layer of the ductus deferens. A "trophic" influence of the large smooth muscle cells of the ductus deferens on their nerves not only in regard to their noradrenaline, but also on their NPY content is discussed.     

A histochemical and immunohistochemical study of the autonomic innervation of the lower urinary tract of the female pig. Is the pig a good model for the human bladder and urethra?

The detrusor muscle, bladder neck, proximal, middle and distal regions of the urethra of the female pig were studied by histochemical and immunohistochemical methods to localize catecholamine-containing, acetylcholinesterase-positive and peptide-containing nerves. The peptides examined included: vasoactive intestinal polypeptide, substance P, somatostatin, [Met]enkephalin, bombesin and gastrin. The greatest density of nerves was found in the smooth muscle of the distal urethra, followed by the bladder neck, middle urethra, and proximal urethra, with the least in the detrusor muscle. The greatest number of nerve fibres stained for acetylcholinesterase, followed by vasoactive intestinal polypeptide- and catecholamine-containing fibres. Substance P-immunoreactive nerve fibres were confined to the bladder neck and distal urethral regions. [Met]enkephalin-and gastrin-immunoreactive nerves were most dense in the distal urethra but absent in detrusor muscle, while somatostatin-immunoreactive nerve fibres were sparsely distributed throughout the lower urinary tract. No nerve fibres showing immunoreactivity to bombesin were found. Catecholamine-containing, acetylcholinesterase-positive, vasoactive intestinal polypeptide-, substance P-, [Met]enkephalin- and gastrin-immunoreactive nerves were also found on the adventitial-medial border of blood vessels in the pig urinary tract. In the intrinsic external urethral sphincter, located in the distal urethra, vasoactive intestinal polypeptide- and gastrin-immunoreactive nerve fibres were found bordering a small number of individual striated muscle fibres, while catecholamine-containing nerves were found predominantly in the connective tissue surrounding the striated muscle fibres. Dense populations of acetylcholinesterase-positive nerve fibres were found associated with the striated muscle fibres, with end plates on some of them. Intramural ganglia, composed of two to 30 neurones, were found in the bladder neck and middle and distal regions of the urethra. In the smooth muscle, and in the vicinity of the striated muscle regions of the intrinsic external urethral sphincter, there were small ganglia, containing two to three neurones, which were vasoactive intestinal polypeptide-, [Met]enkephalin- and somatostatin-immunoreactive. The results are compared to the autonomic innervation of the human bladder and urethra as previously described and it is concluded that the lower urinary tract of the pig is a good model for some features of the lower urinary tract of man, but a poor model for others.     

Immunohistochemical demonstration of substance P in the lower respiratory tract of the rabbit and not of man

Substance P (SP)-immunoreactive nerve fibres were searched for at all levels of both fetal and adult human lower respiratory tract. Because the demonstrability of substance P immunoreactivity varies between different animal species, rabbit pulmonary tissue was also subjected to SP immunohistochemistry. Human irises and corneas served as positive human controls. The specimens were taken from 10 human lungs during pulmonary operations. Tracheal tissue was obtained from three patients during bronchoscopy. Five fetal human lungs were examined. Human specimens examined included the trachea, main bronchi, segmental bronchi, and peripheral pulmonary tissue. In addition, the tracheobronchial tissues of four rabbits were studied. SP immunoreaction was demonstrated in formaldehyde-fixed cryostat sections by either the indirect immunofluorescence technique or the peroxidase-antiperoxidase procedure. Both monoclonal and conventional antibodies to SP were tested. In the rabbit SP-immunoreactive nerves were found in both the submucosa and the smooth muscle layer of the main bronchi and trachea. Specimens from human trachea, bronchi, and bronchioli were all negative. Since the SP immunoreaction was easily demonstrated in both human cornea and human iris, it was concluded that there are no SP-immunoreactive nerves in the human pulmonary tissues or that their SP content is very low and below the sensitivity of all the techniques used.     

SENSORY RECOVERY AFTER HAND REIMPLANTATION: A CLINICAL,MORPHOLOGICAL, AND NEUROPHYSIOLOGICAL STUDY IN HUMANS

Despite fairly good return of motor function, patients who have amputated hands reimplanted demonstrate poor sensory recovery and severe cold intolerance, two variables that are difficult to quantify reliably. In this study we wanted to find out if there is a correlation between morphological findings of sensory and sympathetic reinnervation and clinical and neurophysiological variables. Skin was biopsied from the reimplanted and corresponding area in the normal hands of eight patients who had sustained a hand amputation and subsequent reimplantation. The sections were immunostained using markers for both sensory and sympathetic nerve fibres. Comparison between the reimplanted and normal sides in each individual showed a mean loss of sensory immunoreactive nerve fibres of 30%, and for sympathetic immunoreactivity the loss was 60%. There was measurable two-point discrimination in the injured hand only in patients below the age of 40 years, corresponding to the better recovery of mechanical thresholds evaluated neurophysiologically for this age group. These results confirm the extensive loss of sensory nerve fibres after nerve injury, probably correlated to loss of sensory neurons. We have also shown that it is possible to correlate the results of clinical and neurophysiological evaluation with morphological results of skin reinnervation specific to the repaired nerve, and so improve the possibility for the quantification of sensory recovery.     

Neurone-specific enolase and S-100: new markers for delineating the innervation of the respiratory tract in man and other mammals.

Lung innervation has been studied in the past by methylene blue staining and silver impregnation and more recently by histochemical methods. These techniques give only a partial picture of the total innervation. We have delineated the innervation of the lung in man and three other mammalian species by immunostaining with antibodies to two new markers of nervous tissue. These markers are neurone-specific enolase (NSE), an enzyme present in nerve cells in both the central and the peripheral nervous systems, and S-100, a protein found in glial cells. Throughout the respiratory tract NSE was localised in ganglion cells and nerve fibres in all species examined, while S-100 was found in the supporting glial cells of ganglia and in Schwann cells of peripheral nerves. The distribution of NSE immunoreactivity in serial sections was compared with that of acetylcholinesterase-containing, noradrenergic, and peptide-containing nerves. In all areas NSE was found to be a specific marker for all three types of nerves. Thus these two antibodies provide an effective histological means of examining both the neuronal and the non-neuronal components of the lung innervation and should be of value in investigating this system in lung disease.     

Sensory recovery after hand reimplantation: a clinical, morphological, and neurophysiological study in humans.

Despite fairly good return of motor function, patients who have amputated hands reimplanted demonstrate poor sensory recovery and severe cold intolerance, two variables that are difficult to quantify reliably. In this study we wanted to find out if there is a correlation between morphological findings of sensory and sympathetic reinnervation and clinical and neurophysiological variables. Skin was biopsied from the reimplanted and corresponding area in the normal hands of eight patients who had sustained a hand amputation and subsequent reimplantation. The sections were immunostained using markers for both sensory and sympathetic nerve fibres. Comparison between the reimplanted and normal sides in each individual showed a mean loss of sensory immunoreactive nerve fibres of 30%, and for sympathetic immunoreactivity the loss was 60%. There was measurable two-point discrimination in the injured hand only in patients below the age of 40 years, corresponding to the better recovery of mechanical thresholds evaluated neurophysiologically for this age group. These results confirm the extensive loss of sensory nerve fibres after nerve injury, probably correlated to loss of sensory neurons. We have also shown that it is possible to correlate the results of clinical and neurophysiological evaluation with morphological results of skin reinnervation specific to the repaired nerve, and so improve the possibility for the quantification of sensory recovery.     

Effects of ketamine and halothane on normal and asthmatic smooth muscle of the airway in guinea pigs

in vitro preparations of trachea isolated from normal and asthmatic guinea pigs were used to measure their maximum contractile response to histamine challenge and to determine spontaneous relaxation of smooth muscle of the airway. The effect of ketamine and halothane on these reactions was investigated. The optimal ketamine concentration was found to be 10 μg/ml. This dose attenuated the maximum contraction and produced greater relaxation (p < 0.01) of isolated trachea. However, ketamine failed to prevent an anaphylactic (Schultz-Dale) response when antigen (one per cent albumin) was added in an experimental chamber containing pre-sensitized guinea pig trachea. In contrast, halothane abolished any response to histamine challenge and prevented development of the Schultz-Dale response of smooth muscle from the airway of asthmatic guinea pigs.     

Autonomic innervation of tendons, ligaments and joint capsules. A morphologic and quantitative study in the rat.

We analyzed the neuronal occurrence of autonomic transmitters; noradrenaline (NA), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), in the Achilles tendon, medial and lateral collateral ligaments and knee joint capsule in the rat--by immunohistochemistry (IHC). In addition, the tissue concentrations of the sympathetic neuropeptide, NPY, and the parasympathetic peptide, VIP, were determined by radioimmunoassay (RIA). IHC demonstrated nerve fibers containing sympathetic vasoconstrictors--NA and NPY--and the parasympathetic vasodilator, VIP, in all tissues. NPY- and NA-positive nerve fibers were predominantly observed in larger blood vessels, whereas, nerve fibers immunoreactive to VIP were found in smaller vessels. In many nerve fibers a co-localization of the transmitters was seen. RIA showed that the concentration of NPY compared to VIP was 15-times higher in ligaments and twice as high in tendons and capsules. The differences noted may reflect a difference in vulnerability to degenerative conditions. In pathological conditions, dysregulation of autonomic transmitters in hypovascularized tissues subjected to repetitive mechanical load may contribute to tissue hypoxia leading to degeneration and rupture of tendons and ligaments.     

豚鼠阴茎海绵体中ICC和NO信号通路的形态学关系

目的初步探讨豚鼠阴茎海绵体组织中cajal间质细胞（ICC）和神经型一氧化氮合成酶（nNOS）阳性神经元的分布及两者的组织学关系。方法①制作成年豚鼠阴茎海绵体组织冰冻切片,利用c-kit/nNOS免疫荧光双染技术,激光共聚焦扫描显微镜（LSCM）下观察阴茎海绵体ICC及nNOS阳性神经元的形态及分布情况。②酶消化法体外培养阴茎海绵体ICC,c-kit/nNOS免疫荧光双染,LSCM下观察细胞形态及c-kit和nNOS的表达情况。结果 ICC分布在阴茎海绵体平滑肌小梁边缘及平滑肌肌间,纺锤形,具有长的突起,胞体呈圆形或椭圆形,并且表达nNOS;阴茎海绵体平滑肌小梁边缘及平滑肌肌间同时分布有ICC和nNOS阳性神经元,局部nNOS阳性神经主干附近可见较多ICC分布。结论豚鼠阴茎海绵体ICC与nNOS阳性神经元组织联系紧密,ICC可能参与阴茎海绵体内NO神经信号的传递。     

A study of the myelinated fibres in the branches of the pelvic plexus

In a 20-year-old human female specimen the nerves to the pelvic organs were dissected and analysed. The gross anatomy of the branches of the pelvic plexus was described. The composition of these nerves was studied and the sizes and distribution of the diameter of a great part of the myelinated nerve fibres were measured and analysed. It was confirmed that the ventral roots S2 and S3 contain many nonmyelinated nerve fibres. There are direct connections between the sacral sympathetic chain and the pelvic plexus. They contain myelinated fibres with sizes as large as 11 μm. There are two different groups of fibres which supply the bladder, one on the dorsal side, mainly nonmyelinated (postganglic sympathetic?), and another group to the lateral side which contains many thin myelinated fibres (parasympathetic preganglionic?). The pelvic plexus and its branches are fixed to the vagina and the rectum. Surgical interventions in this area and perhaps also childbirth can damage the nerve supply to the bladder and the urethra. The functional disturbances of the bladder after such interventions can depend on what group of nerve fibres is most seriously damaged. The large number of thick myelinated fibres which reach the ventro lateral side of the urethra makes it highly probable that these fibres innervate the intrinsic striated urethral musculature. The large number of nonmyelinated nerve fibres in the nerves to the m. levator ani probably innervate smooth muscle tissue which is found in the fasciae of the pelvic floor.     

Demonstration of intrinsic innervation of the guinea pig upper urinary tract using whole-mount preparation

AIMS: The morphology and functional importance of the autonomic nervous system in the upper urinary tract is still not completely understood. Previous histological studies investigating the innervation of the urinary tract have mainly used conventional sections in which the three-dimensional structure of the intramural innervation is difficult to achieve. In contrast, the whole-mount preparation technique is a suitable method for visualizing the distribution of the mesh-like neuronal networks within the urinary tract. METHODS: The distribution and regional variation of neurofilament (NF), tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), and substance P-immunoreactive (SP-IR) neurons, as well as acetylcholinesterase (AChE) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons were investigated using whole-mount preparations of the guinea pig upper urinary tract. RESULTS: Two distinct nervous plexuses were detected within the muscle layers containing NF, TH, ChAT, and SP-IR nerves. AChE-positive nerves were seen in all layers. Only moderate NADPH-d-positive innervation was found. Renal pelvis, upper and lower part of the ureter showed an overall increased innervation compared to the middle portion of the ureter. Ganglia were found at the pelviureteric border displaying NF and TH immunoreactivity. CONCLUSION: The whole-mount preparation technique provides an elegant method for assessing the three-dimensional architecture of ureteral innervation. The guinea pig upper urinary tract is richly supplied with adrenergic, cholinergic, nitrergic, and sensory nerves which suggest that the autonomous nervous system plays an important role in controlling ureteral motility and blood flow.     

Peptidergic innervation within the prostate gland and seminal vesicle

Summary An immunohistochemical study in which antisera against several neuropeptides were used demonstrated the presence of neuropeptide Y(NPY) and vasoactive intestinal polypeptide (VIP) immunoreactivity in nerve fibers in the human prostate gland and seminal vesicle, whereas no immunostaining for substance P and calcitonin gene-related peptide was observed. The peptidergic innervation was found to be generally moderate to low. NPY-and VIP-immunoreactive fibers were localized in the subepithelial connective tissue as well as the smooth muscle layers in both organs, although the peptidergic fiber networks were more prominent in the seminal vesicle. Most NPY-immunoreactive fibers were observed in the musculature of the seminal vesicle.In addition, NPY-and VIP-immunoreactive fibers were demonstrated in the walls of blood vessels. The results of our study suggest that the innervation of the prostate gland and seminal vesicle by various neuroactive peptides may be involved in the autonomic regulation of these organs in adult man, as well as sympathetic and parasympathetic nerve fibers.The work reported in this paper was supported by the Walter-Schulz-Stiftung and the Friedrich-Baur-Stiftung     

The distribution of vesicular acetylcholine transporter in the human male genitourinary organs and its co-localization with neuropeptide Y and nitric oxide synthase

Because doubt still remains concerning the distribution of nerves that are unequivocally cholinergic in the human genitourinary organs, we have used a specific marker, namely, an antibody to vesicular acetylcholine transporter (VAChT), to immunolabel cholinergic axons and cell bodies in specimens of urinary bladder, seminal vesicle, vas deferens, and prostate gland obtained from neonates and children post mortem. In addition some sections were double-immunolabeled with VAChT and either neuropeptide Y (NPY) or nitric oxide synthase (NOS). The results demonstrated a rich cholinergic innervation to the muscle coat of the bladder body with a much less prominent, but nonetheless significant, cholinergic innervation to the smooth muscle components of the seminal vesicle, vas deferens, and prostate. Small ganglia were scattered throughout the detrusor muscle of the urinary bladder, approximately 75% of the intramural neurons being VAChT immunoreactive, whereas approximately 95% contained NPY and approximately 40% contained NOS. VAChT immunoreactivity was observed in 40% of neurons in ganglia scattered throughout the pelvic plexus. Almost all these cholinergic neurons contained NPY and approximately 65% contained NOS. Almost all the cholinergic nerve fibers throughout the genitourinary organs also contained NPY. Although NOS was sparse in the cholinergic nerves of the bladder body, it occurred in the majority of cholinergic nerves at the bladder neck and was also present in a proportion of the cholinergic nerves in the other organs examined. VAChT-immunoreactive nerves were also observed in a sub-epithelial location in all the organs examined, the majority containing NPY, whereas a small proportion contained NOS. Although doubt remains about the function of sub-epithelial cholinergic nerves in the urinary bladder, the majority of similar nerves in the seminal vesicle, vas deferens, and prostate gland are considered to be secretomotor. Collectively these findings demonstrate that the cholinergic innervation of the male genitourinary system is well established in the neonate and child. Neurourol. Urodynam. 19:185-194, 2000.     

Peptide-containing nerves in human urinary bladder

Nerves containing immunoreactive vasoactive intestinal polypeptide (VIP), substance P and two newly discovered peptides, neuropeptide tyrosine (NPY) and PHI (peptide having N-terminal histidine and C-terminal isoleucine), have been found in the human urinary bladder by immunocytochemistry and radioimmunoassay. Somatostatin immunoreactivity was detected by radio-immunoassay. The VIP-immunoreactive nerves were widely distributed in all regions, but were particularly dense beneath the epithelium and in the muscle layer. Scattered intramural ganglia were found to be reactive to VIP antiserum. Higher concentrations of extractable VIP were detected in the trigone than in the dome. VIP- and PHI-immunoreactive nerves were similarly distributed, the latter being less numerous. NPY immunoreactive nerves were seen mainly in the muscle layer, particularly in the trigonal area. The distribution patterns of VIP- and NPY-immunoreactive nerves resembled those of the previously reported cholinergic and adrenergic nerves, respectively. Many blood vessels were found to be innervated by both types of immunoreactive nerves. Scattered substance P-immunoreactive fibers were occasionally seen, being present in the submucosa and around the detrusor muscles. The significance of these nerves remains to be elucidated.     

Neuropeptide Y- and vasoactive intestinal polypeptide-containing nerves in the intrinsic external urethral sphincter in the areflexic bladder compared to detrusor-sphincter dyssynergia in patients with spinal cord injury

Specimens of urethra were obtained from patients with cervical and thoracic spinal cord lesion with detrusor-sphincter dyssynergia and from patients with lower motor neurone lesion with detrusor areflexia, undergoing transurethral sphincterotomy. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) in nerves associated with both the smooth and striated muscle components of the urethral sphincter were studied immunohistochemically and by immunoassay. In patients with detrusor-sphincter dyssynergia following cervical and thoracic spinal cord injury, NPY- and VIP-immunoreactive varicose nerve fibres were seen in both the smooth and striated muscle components of the urethral sphincter. In the smooth muscle, NPY- and VIP-immunoreactive nerves did not appear to have any particular orientation, but in the striated muscle region they were found to run along the length of individual muscle fibres. In patients with detrusor areflexia following lower motor neurone lesion, while the pattern, density and fluorescence intensity of NPY- and VIP-immunoreactive nerves in the smooth muscle of the sphincter mechanism appeared the same as seen in patients with detrusor-sphincter dyssynergia, there was a marked increase in the density of these nerves in the striated muscle region of the sphincter mechanism. Quantitation of the peptides by immunoassay was consistent with the histochemical findings, with significantly higher levels of both NPY and VIP in the striated muscle of patients with lower motor neurone lesion, compared to those with cervical and thoracic spinal cord lesion, p = 0.04. NPY and VIP levels in urethral smooth muscle were in the same range in lower motor neurone lesion patients and cervical and thoracic spinal cord lesion patients. We conclude that there are increased NPY- and VIP-containing fibres in striated muscle of the intrinsic external urethral sphincter in patients with areflexic bladder compared with those with detrusor-sphincter dyssynergia.     

Mechanisms of excitatory transmission in circular smooth muscles of the guinea pig seminal vesicle

PURPOSE: Cellular mechanisms of excitatory neuromuscular transmission in circular smooth muscles of the seminal vesicle were investigated. MATERIALS AND METHODS: Circular smooth muscles of the seminal vesicle of the guinea pig were isolated. Changes in membrane potential produced by transmural nerve stimulation were recorded using intracellular microelectrode techniques. Changes in the intracellular Ca ion concentration induced by transmural nerve stimulation were measured in preparations loaded with Ca indicator fura-PE3. Responses produced by bath applied norepinephrine and alpha,beta-methylene adenosine triphosphate (ATP) were also examined. RESULTS: Transmural nerve stimulation evoked excitatory junction potentials that triggered action potentials and also caused transient increases in [Ca2+] (Ca transients). Nifedipine abolished action potentials, leaving underlying excitatory junction potentials unchanged, and reduced the amplitude of Ca transients. Excitatory junction potentials were blocked by alpha,beta-methylene ATP or guanethidine but not by phentolamine. A train of transmural nerve stimulation evoked oscillatory changes in membrane potential and [Ca2+], which were abolished by phentolamine or inhibited by nifedipine. Nifedipine insensitive components were abolished by cyclopiazonic acid. Norepinephrine depolarized the membrane and elicited oscillatory potentials with an associated elevation in [Ca2+]. These responses were inhibited by nifedipine and abolished by additional application of cyclopiazonic acid. Transient depolarization with an associated increase in [Ca2+] was elicited by alpha,beta-methylene ATP and [Ca2+] responses but no potential changes were inhibited by nifedipine. CONCLUSIONS: Circular smooth muscles of the guinea pig seminal vesicle receive a projection of sympathetic nerves that release norepinephrine to initiate slow depolarization through the activation of alpha-adrenoceptors. These nerves also release ATP to elicit excitatory junction potentials. Neurally released norepinephrine and ATP are increased [Ca2+] by the influx of Ca2+ through L-type Ca2+ channels and also by the release of Ca2+ from internal stores.     

Quantitative immunohistochemical study of the innervation of the guinea-pig lower urinary tract

OBJECTIVE: To study the innervation of the different muscle systems of the guinea-pig lower urinary tract, using immunohistochemical and enzyme histochemical methods. MATERIALS AND METHODS: Serial cryostat sections of both genders (four guinea-pigs each) were quantitatively analysed for cholinergic, adrenergic and peptidergic nerve fibre density using specific antibodies or enzyme histochemical labelling. Smooth muscle cell nuclei and varicosities or sectioned nerves were counted in detrusor, internal vesical sphincter (VS), ventral longitudinal musculature (VLM), and dorsal longitudinal musculature (DLM), and the ratios of nerves/nucleus (for detrusor, VLM and DLM) were evaluated statistically. The striated and the smooth external sphincter were examined qualitatively. RESULTS: Detrusor, VS, VLM and DLM had significantly different innervation patterns. In detrusor muscle parasympathetic nerve fibres dominated, while the VS and the urethral muscles had a major sympathetic nerve supply. Neuropeptide Y-positive nerve fibres were abundant in all of the muscles. CONCLUSIONS: Smooth muscles of the lower urinary tract of the guinea-pig are distinct muscular units with distinct innervation patterns. Although there are no corresponding studies in humans the general innervation seems to be equivalent in human and guinea-pig, qualifying the guinea-pig for comparative urological studies.     

Intramural ganglia in the human urethra

The urethras from five patients with a thoracic or cervical spinal cord lesion and one patient with carcinoma of the bladder were studied immunohistochemically for neuropeptide Y and vasoactive intestinal polypeptide. Autonomic ganglia, containing two to 21 nerve cell bodies, were found in the smooth and striated muscle regions of the intrinsic external urethral sphincter; they were present rarely in the distal urethra and were absent from the prostatic urethra. Neuropeptide Y immunoreactivity was observed in some of the nerve cell bodies (diameter 25 to 50 microns). Vasoactive intestinal polypeptide immunoreactivity was observed in small cells (diameter 15 to 25 microns.) in the urethral smooth muscle and in the walls of blood vessels that resembled small intensely fluorescent cells but may be nerve cell bodies. Both neuropeptide Y- and vasoactive intestinal polypeptide-immunoreactive nerve fibres were found in the smooth muscle and around blood vessels in the urethra of all patients. Both types of peptide-containing nerves were found associated with striated muscle of the intrinsic external urethral sphincter in patients with spinal cord injury, but only vasoactive intestinal polypeptide-immunoreactive nerves were found in the patient with carcinoma of the bladder in this region. The functions of the autonomic ganglia and vasoactive intestinal polypeptide- and neuropeptide Y-immunoreactive nerves in the human urethra remain to be elucidated.