Vasoactive Intestinal Polypeptide-immunoreactive Nerve Fibers Research Articles

Re-innervation pattern of the ‘neovagina’ created from the bladder flap in patients with Mayer-Rokitanski-Kistner-Hauser syndrome: An immunochemical study

Background. Cystovaginoplasty (CVP) is a method of vaginal reconstruction in women with Mayer-Rokitansky-Kistner-Hauser Syndrome (MRKHS). The neo-vagina allows normal sexual intercourses, but after CVP, the sexual life of patients with MRKHS does not differ significantly from normal females. Therefore, we decided to elucidate the pattern of sensory re-innervation of the bladder flap used for the surgery.Methods. Biopsies were taken from vaginal vestibule and urinary bladder during the CVP and 1 year later in four patients with MRKHS. The following neurotransmitters were studied calcitonin gene-related peptide (CGRP), galanin (GAL), vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP).Results. CGRP and PACAP nerve fibres were sparse under the urothelium and in submucosal layer of the neovagina, they were more numerous around blood vessels and in the vicinity of smooth muscles. This was similar to the pattern observed in the urinary bladder. VIP- and GAL-positive nerve fibres were most numerous in the submucosa around blood vessels and in smooth muscle bundles of neovagina. They were distinctly less numerous beneath the epithelium. This innervation pattern mimicked that seen in normal vagina and in vaginal vestibule of patients with MRKHS.Conclusions. Our findings demonstrate considerable nervous system plasticity in the bladder flap. Distribution of presumably sensory CGRP and PACAP immunoreactive nerve fibers was similar to the pattern observed within the intact bladder wall, and VIP or GAL immunoreactive nerve fibers (vasomotor functions) were distributed in a manner similar to that observed in the intact vaginal wall.

Large veins in the Atlantic cod (Gadus morhua) and the rainbow trout (Oncorhynchus mykiss) are innervated by neuropeptide-containing nerves.

Previous studies have shown that fish veins are reactive to several hormones known to exist in the fish circulation. Besides this humoral control, another possible means of active regulation of venous return is by autonomic nervous control of venous tone. This study therefore investigated the presence of a perivascular innervation of major veins in the Atlantic cod (Gadus morhua) and the rainbow trout (Oncorhynchus mykiss) using immunohistochemical methods. Histological staining was employed to investigate the smooth muscle distribution in the vessel walls. Vasoactive intestinal polypeptide-immunoreactive nerve fibers were found to be widespread in the venous system of G. morhua and O. mykiss, while pituitary adenylate cyclase-activating polypeptide-immunoreactive fibers were demonstrated in the duct of Cuvier of both species. Fibers containing neurokinin A and/or substance P were found in the duct of Cuvier and the posterior cardinal vein of both species and in the hepatic portal vein of O. mykiss. Calcitonin-gene related peptide-immunoreactive fibers were present in the duct of Cuvier of both species and in the hepatic portal vein of O. mykiss. Galanin-immunoreactive fibers were found in the duct of Cuvier in O. mykiss and in the hepatic portal vein of both species. Co-existence of neuropeptides in the perivascular nerve fibers was investigated by double labelling. Vasoactive intestinal polypeptide/pituitary adenylate cyclase-activating polypeptide-immunoreactive fibers were found in both species. Vasoactive intestinal polypeptide/galanin-immunoreactive fibers and vasoactive intestinal polypeptide/calcitoningene related peptide-immunoreactive fibers were found in G. morhua but not in O. mykiss. This study gives further evidence for an active venoregulation by autonomic nerves in teleost fish.

Comparative study on the appearance of various bioactive peptides in foregut derivates during the ontogenesis

Bioactive peptides have an important multifunctional role in the gastrointestinal tract. In the present study we have investigated the dynamism of the appearance of PACAP (pituitary adenylate cyclase activating polypeptide), VIP (vasoactive intestinal polypeptide), gastrin, and secretin immunoreactivities in human foregut derivates during the ontogenesis using an immunohistochemical approach. None of these peptides were observed in the foregut derivates of an 8-week-old embryo. VIP immunoreactive nerve fibers appeared by the 11th week in the smooth muscle layers of the stomach. No other peptide immunoreactivities were observed of this stage. In 18- and 20-week old fetuses PACAP, secretin, and gastrin immunoreactive cells appeared in the developing glands of the stomach. In the duodenum gastrin immunoreactivity was present in the Lieberkühn's glands and secretin immunoreactive cells were seen between the surface epithelial cells. In the pancreas secretin immunoreactivity was found in the Langerhans islets; however, PACAP immunreactivity was observed in the exocrine portion. The distribution of VIP fibers did not change during the fetal life and it was similar to the adult pattern. According to our results the appearance of PACAP, secretin, and gastrin in the developing glands suggests their role in the proliferation and differentiation of the epithelial derivates.

Immunohistochemical localization of the VIP1 receptor (VPAC1R) in rat cerebral blood vessels: relation to PACAP and VIP containing nerves.

The two structurally related peptides, vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP), are present in cerebral vascular nerve fibers. Biologic actions of VIP are exerted through two receptors, VPAC1 and VPAC2, having similar binding affinity for both VIP and PACAP. In the current study, the authors have developed a specific antibody against the rVPAC1 receptor to examine the localization of rVPAC1 immunoreactivity in cerebral arteries and arterioles of the rat by immunohistochemistry using fluorescence confocal microscopy. Specificity of the antiserum was ensured by immunoblotting and immunocytochemistry of cells transfected with cDNA encoding the different PACAP-VIP receptor subtypes. The rVPAC1 receptor immunoreactivity was localized to the plasmalemma of circularly orientated smooth muscle cells on superficial cerebral arteries and arterioles taken from the basal surface of the brain. By double immunostaining VIP immunoreactive nerve fibers and, to a lesser extent, those containing PACAP were shown to have intimate contact with the receptor protein. Vasoactive intestinal polypeptide and PACAP containing cerebrovascular nerve fibers were found in separate nerve populations with different distribution pattern and density. In brain sections processes of cortical VIP-, but not PACAP-, containing neurons seemed to innervate the rVPAC1 receptor of pial arterioles on the brain surface. The current findings provide the neuroanatomical substrate for a role of VIP and maybe PACAP in the regulation of cerebral blood flow.

Regional difference in the distribution of vasoactive intestinal polypeptide-immunoreactive nerve fibres along the uterus and between myometrial muscle layers in the rat.

To investigate a possible regional variation of the vasoactive intestinal polypeptide innervation in the uterus of the cyclic rat, the distribution of vasoactive intestinal polypeptide-containing nerve fibres from the cervix to the oviduct end of the uterine horns was studied using immunohistochemistry. Immunoreactive nerve fibres were most concentrated in the cervix, where they formed a dense plexus in association with the musculature and surrounding blood vessels. In the uterus, a clear regional distribution of the vasoactive intestinal polypeptide innervation was observed. Numerous vascular and non-vascular immunoreactive nerve fibres were present in the lower part of the uterine horns, whereas they were sparse in the median region and absent at the oviduct end. Moreover, non-vascular peptide innervation was mostly concentrated in the circular layer of the myometrium and also occurred in the endometrium. Only a very few immunoreactive nerve fibres were present in the longitudinal muscle layer. No change in the peptide innervation pattern was observed during the different stages of the sexual cycle. The marked regional distribution of the peptide innervation in the rat uterus suggests that the regulatory effects of the peptide occur mainly in the lower part of the organ and principally affect the circular muscle layer in the myometrium.

Inhibition of nitroxidergic nerve function by neurogenic acetylcholine in monkey cerebral arteries.

1. Modification by endogenous or exogenous acetylcholine and vasoactive intestinal polypeptide (VIP) of vasodilatation mediated by nitric oxide (NO) released from nitroxidergic nerves was studied in isolated monkey cerebral arteries. In arterial strips denuded of endothelium, transmural electrical stimulation (2-20 Hz) produced relaxations that were abolished by tetrodotoxin. 2. The relaxation response was attenuated by acetylcholine, and the attenuation was reversed by atropine. Attenuation was also observed with AF-DX 116, an antagonist of the muscarinic acetylcholine receptor subtype, M2. NO-induced relaxation was not affected by acetylcholine. Neurogenic relaxation was also inhibited by physostigmine and potentiated by atropine. 3. VIP in concentrations that elicited slight relaxation did not alter the response to nerve stimulation. In the strips showing tachyphylaxis to VIP, the neurogenic response was not inhibited. 4. Histochemical studies of whole-mount preparations revealed nerve fibres with NO synthase and VIP immunoreactivity, and also acetylcholinesterase, suggesting the presence of perivascular nitroxidergic, VIPergic and cholinergic innervation. 5. It is concluded that the actions of nitroxidergic nerve fibres on the monkey cerebral artery are inhibited by nerve-released acetylcholine acting on prejunctional muscarinic receptors, possibly of the M2 subtype. Despite the presence of VIP immunoreactive nerve fibres and the ability of exogenous VIP to relax the artery, there is no evidence supporting either a prejunctional modulation of nitroxidergic nerve function by VIP or a role for VIP as a vasodilatory neurotransmitter.

Distribution of vasoactive intestinal polypeptide immunoreactive nerve fiber in the rat nasal mucosa

The distribution of vasoactive intestinal polypeptide (VIP)-immimoreactive nerve fiber of the respiratory nasal mucosa of the rat was examined by use of immunohistochemistory with light, laser confocal scanning and electron microscopy. On light microscopy, it was observed that VIP immunoreactive nerve fibers distributed under and within the epithelium in addition to around the blood vessels and glands. The laser confocal scanning microscope revealed the network of VIP-immunoreactive nerve fibers at glands, but it was denser around glands than within glands. The VIP-immunoreactive nerve fibers formed fine varicosities and was distributed below the middle portion of the epithelium. Some fibers were observed as if they were surrounding goblet cells. Electron microscopy showed that the VIP-immunoreactive nerve fibers within the epithelium were terminated as free nerve endings. Some of them were in close contact with goblet cells.

Selective damage to sensorimotor perivascular nerves in the mesenteric vessels of diabetic rats.

The perivascular innervation of the superior mesenteric artery and vein was examined using immunohistochemical and immunoassay techniques in rats 8 weeks after induction of diabetes with streptozotocin (STZ). Increased density of innervation and fluorescence intensity was noted for substance P- and calcitonin gene-related peptide-immunoreactive nerves in the diabetic vessels. A slight increase in the density of vasoactive intestinal polypeptide-immunoreactive nerve fibers innervating the mesenteric artery was also noted. However, there was no change in the density of neuropeptide Y- and dopamine beta-hydroxylase-immunoreactive nerve fibers, although the fluorescence intensity of neuropeptide Y-immunoreactive nerve fibers was reduced in diabetic rat vessels. Immunoassays showed that the levels of substance P- and calcitonin gene-related peptide were increased > 10-fold in the diabetic mesenteric vein, while levels of neuropeptide Y and vasoactive intestinal polypeptide were unchanged. In summary, there is a marked increase in nerve fibers containing sensory neuropeptides in mesenteric vessels of STZ-induced diabetic rats, which, in view of the reported impaired sensorimotor function in these vessels, is likely to reflect a neuropathic change.

Neurotransmitters for the Canine Inferior Pharyngeal Constrictor Muscle

The inferior pharyngeal constrictor muscle plays an important role at the pharyngeal phase of deglutition and is anatomically composed of the thyropharyngeal muscle and cricopharyngeal muscle. In this study we investigated the distribution pattern of neuropeptidergic and catecholaminergic nerve fibers in the thyropharyngeal muscle and cricopharyngeal muscle of seven puppies by immunohistochemistry. Some of the calcitonin gene‐related peptide–, substance P–, vasoactive intestinal polypeptide–, and tyrosine hydroxylase–immunoreactive nerve fibers were found to lie parallel to the muscle fibers in both the thyropharyngeal muscle and cricopharyngeal muscle. Nerve fibers with immunoreactivity to all substances examined were found to be associated with blood vessels in both the thyropharyngeal muscle and cricopharyngeal muscle, and the number of calcitonin gene‐related peptide, neuropeptide Y, and tyrosine hydroxylase nerve fibers was higher than the number of substance P, vasoactive intestinal polypeptide, and galanin nerve fibers. Motor end plate‐like structures with calcitonin gene‐related peptide immunoreactivity were found in both the thyropharyngeal muscle and cricopharyngeal muscle. These structures in the cricopharyngeal muscle were clearly less than those in the thyropharyngeal muscle. Some clusters of neurons were detected only in the cricopharyngeal muscle of all dogs examined. Substance P–, vasoactive intestinal polypeptide–, galanin–, and neuropeptide Y–immunoreactive neurons were found in this ganglion, and the vasoactive intestinal polypeptide–immunoreactive neurons were the most abundant. Abundant calcitonin gene‐related peptide– and vasoactive intestinal polypeptide–immunoreactive nerve fibers, and some substance P– and galanin‐immunoreactive nerve fibers were distributed in the ganglion. A few neuropeptide Y– and tyrosine hydroxylase‐immunoreactive nerve fibers were also found in the ganglion. These findings suggest the complex participation of neuropeptides in the innervation of the inferior constrictor muscle.

Neuropeptide Y- and vasoactive intestinal polypeptide-like immunoreactivity in adjuvant arthritis: effects of capsaicin treatment.

The occurrence of the neuropeptides vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) in ankle joints and dorsal root ganglia (L2-L6) was analyzed in normal and arthritic Lewis rats. In addition the effect of capsaicin pretreatment was investigated. The study included 92 rats consisting of 4 groups, 23 rats in each; normal rats, normal rats given capsaicin, arthritic rats and arthritic rats pretreated with capsaicin. The localization of the neuropeptides was assessed by immunohistochemistry and the tissue concentrations were determined by radioimmunoassay (RIA). In the arthritic rats, there was a slight increase in NPY immunoreactive nerve fibres in the ankle joint synovium and bone marrow, as compared to normal rats. Notably, there was an intense fluorescence and significant increase (p < 0.01, 41%) in the number of NPY-positive megakaryocytes in the tibial bone marrow of arthritic rats. RIA showed that the concentration of NPY-like immunoreactivity (LI) was increased by 50% in the ankle joint. Pretreatment with capsaicin did not affect the increased level of NPY-LI in the ankle joint of arthritic rats. The concentration of NPY-LI in the dorsal root ganglia was not altered in arthritic rats, nor was it affected by the capsaicin treatment. No NPY immunoreactive cells could be detected in the dorsal root ganglia. The number of VIP immunoreactive nerve fibres observed in ankle joints of arthritic and normal rats did not differ. However, RIA measurements showed an 11% increase in the VIP concentration in arthritic rats, which was unaffected by capsaicin treatment. In dorsal root ganglia, RIA disclosed a 21% increase in VIP-LI, although no VIP-positive cells could be detected. Capsaicin treatment did not affect the increased concentration of VIP-LI in the dorsal root ganglia.

Neuropeptide Y, tyrosine hydroxylase and vasoactive intestinal polypeptide-immunoreactive nerve fibers in the vertebral bodies, discs, dura mater, and spinal ligaments of the rat lumbar spine.

The occurrence of autonomic nerves in the lumbar spine of rats was investigated by immunohistochemical technique. Both peptidergic nerves, represented by immunoreactivity to neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), and noradrenergic nerves as reflected by tyrosine hydroxylase (TH) immunoreactivity, were identified. NPY- and TH-positive nerves were predominantly found in the blood vessels walls. They occurred in the bone and periosteum of the vertebral body, disc, dura mater, and in the spinal ligaments. They were particularly numerous along the growth plate and in the outer layers of the intervertebral discs. VIP-positive fibers were predominantly nonvascular. They occurred in all tissues analyzed, but were most abundant in the vertebral bone marrow and periosteum. The VIP-immunoreactive fibers in the outer fibrous layers of the disc and the spinal ligaments were occasionally observed in blood vessel walls. No immunoreactivity could be detected in the nucleus pulposus. In the dura mater, NPY-, TH- and VIP-positive fibers were found both in the ventral and dorsal portion. In view of the vasoconstrictive properties of both NPY and noradrenaline, it may be assumed that the abundance of NPY- and TH-immunoreactive nerves fibers in blood vessel walls reflects a vasoregulatory activity. The predominance of nonvascular VIP-positive fibers in the vertebral bone marrow and periosteum may represent an involvement in local bone physiology.

Peptide-containing neurons in different regions of the submucous plexus of human sigmoid colon

Specimens of the sigmoid colon were obtained from male and female patients (n = 11) with carcinoma of the colon or rectum and studied immunohistochemically for vasoactive intestinal polypeptide-, somatostatin-, substance P-, neuropeptide Y-, calcitonin gene-related peptide-, met- and leu-enkephalin-, 5-hydroxytryptamine-, and dopamine β-hydroxylase-containing nerves. In the subdivisions of the submucous plexus (namely, Schabadasch's, Meissner's, and the intermediate plexuses), substance P- and vasoactive intestinal polypeptide-immunoreactive nerve fibers were the most numerous, and equal densities of these nerves were found in all three layers. In contrast, few neuropeptide Y-, met-enkephalin-, leu-enkephalin-, calcitonin gene-related peptide-, somatostatin-, 5-hydroxytryptamine-, and dopamine β-hydroxylase-immunoreactive nerves were found in these regions. The nerve cell bodies of the submucous plexus contained vasoactive intestinal polypeptide, substance P, leu-enkephalin, somatostatin, and 5-hydroxytryptamine but not neuropeptide Y, met-enkephalin, calcitonin gene-related peptide, and dopamine β-hydroxylase. Vasoactive intestinal polypeptide-containing nerve cell bodies were found in all three subdivisions. Substance P-, leu-enkephalin-, and somatostatin-immunoreactive nerve cell bodies were found in Schabadasch's plexus and the intermediate region of the submucous plexus, but they were absent from Meissner's plexus; 5-hydroxytryptamine-containing nerve cell bodies were only observed in Schabadasch's plexus. The possible function of the neuropeptide-, dopamine β-hydroxylase-, and 5-hydroxytryptamine-containing neurons in the different layers of the submucous plexus is discussed.

Co-localization of vasoactive intestinal polypeptide and neuropeptide Y immunoreactivities in the nerve fibers of the rat adrenal gland

The co-localization of Vasoactive Intestinal Polypeptide (VIP) with Neuropeptide Y (NPY) or its C-flanking peptide (C-PON) was investigated with immunocytochemistry methods in the adrenal gland of the rat. Most of the VIP immunoreactive (+) nerve fibers found in the capsule/glomerular zone also exhibited NPY or C-PON immunoreactivity (IR). We found that at least two populations of VIP varicose nerve fibers can be observed, the most prevalent exhibited both VIP/NPY or VIP/C-PON IR and the other which was rather scarce lacked NPY or C-PON IR. In the superficial cortex VIP/NPY or VIP/C-PON IR nerve fibers were often associated with capsular or subcapsular vascularization and extended into the zona glomerulosa. In the deeper layers of the adrenal cortex radial fibers were closely associated with the inner vascularization of the zona fasciculata and reticularis. In the adrenal medulla NPY or C-PON immunoreactivity was associated with ganglion neurons as well as chromaffin cells; these last cells were always VIP (−). VIP and NPY/C-PON IR could be co-localized in catecholaminergic nerve terminals of the adrenal cortex but not in the adrenal medulla.

Parasympathetic innervation of cutaneous blood vessels by vasoactive intestinal polypeptide-immunoreactive and acetylcholinesterase-positive nerves: Histochemical and experimental study on rat lower lip

The distribution and origin of perivascular acetylcholinesterase-active and vasoactive intestinal polypeptide-immunoreactive nerve fibers were studied in the rat lower lip by means of acetylcholinesterase histochemistry und vasoactive intestinal polypeptide immunohistochemistry. The perivascular nerve fibers stained intensely with both histochemical techniques and were widely distributed on small arteries and arterioles of the lower lip, especially in the transitional zone between the hairy skin and the mucous membrane. The distributions of the two types of fibers were very similar and most of them showed overlapping coloration, on consecutive staining for vasoactive intestinal polypeptide and acetylcholinesterase. Both acetylcholinesterase-positive and vasoactive intestinal polypeptide-immunoreactive fibers were completely lost on removal of the otic ganglion, while they were not affected by sympathetic ganglion removal or sensory nerve sectioning. In the otic ganglion, most cells exhibited acetylcholinesterase activity, and about 60% of the cells showed light to heavy vasoactive intestinal polypeptide immunoreactivity.These findings indicate that vessels in the rat lip are innervated by parasympathctic fibers originating from the otic ganglion and support the view that vasoactivc intestinal polypeptide is present in cholinergic neurons. This may suggest the possible control by the parasympathetic nervous system of cutaneous blood vessels through vasoactive intestinal polypeptide-containing cholinergic neurons, in general or at least in the facial area.

Vasoactive intestinal polypeptide immunoreactivity in the spinal cord of the guinea pig

The distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the lower medulla oblongata and the spinal cord has been analyzed in guinea pigs. This study includes results obtained by colchicine treatment and transection experiments. In the spinal cord, numerous VIP-IR varicosities were observed in the substantia gelatinosa of the columna dorsalis; some were also found in the substantia intermedia and the columna anterior. The spinal VIP-IR nerve fibers were mainly of intraspinal origin and oriented segmentally. VIP-IR nuclei in the spinal cord extended dorsally into corresponding regions of the caudal medulla oblongata, namely from the substantia intermedia medialis and lateralis into the vagus-solitarius complex and from the nucleus spinalis lateralis into the area of the nucleus reticularis lateralis. Additional VIP-IR perikarya were observed in the pars caudalis of the nucleus spinalis nervi trigemini. The VIP-IR nuclei within the caudal medulla oblongata probably form a continuous system with those localized within the spinal cord. They may be involved functionally in the modulation of cardiovascular and respiratory regulation in the guinea pig.

Vasoactive intestinal polypeptide immunoreactive nerve fibres in the human eye.

Immunohistochemistry applied to whole-mount preparations was used to investigate the presence and distribution of vasoactive intestinal polypeptide (VIP) immunoreactive nerves in the non-retinal part of the human eye. The choroid has a dense perivascular supply of VIP immunoreactive nerve fibers, and some free nerve endings within the stroma. These nerves enter the choroid in ciliary nerves and also as perivascular networks around the ciliary arteries. Occasional choroidal VIP immunoreactive nerve cell bodies are seen. The ciliary body stroma, close to the iris root has a dense circumferential plexus of VIP immunoreactive nerve fibers that occur both singly and in bundles. The iris root has a circumferential arrangement of bundles from which VIP immunoreactive nerve fibres travel radially in the stroma. They supply the pupillary region with numerous free nerve endings; the sphincter pupillae is not supplied by these nerves. The cornea is devoid of VIP immunoreactive nerves. These findings, together with existing knowledge of the physiological actions of VIP, indicate that VIP immunoreactive nerves are likely to be involved in the functioning of several ocular tissues.

Vasoactive intestinal polypeptide (vip) as a putative neurotransmitter in penile erection

The localization of vasoactive intestinal polypeptide (VIP) in the male genitourinary tract was investigated in the rabbit and man by means of radioimmunoassay and immunohistochemistry. In addition, the in vitro effect of VIP upon penile smooth muscle from man, the Vervet monkey, and the rabbit was investigated. Significant concentrations of VIP immunoreactivity were found in the human penis and all the organs of the rabbit genital tract apart from the testis. VIP immunoreactive nerve fibres were observed in the erectile tissue of the human and rabbit penis and in the other organs of the rabbit genital tract apart from the testis. Fibres were most abundant in association with blood vessels, in smooth muscle tissue, and subepithelially in glandular tissue. Strips of smooth muscle taken from the corpus cavernosum of Vervet monkey and man showed a dose-dependent relaxation in response to VIP at concentrations of 6 X 10(-8) mol X L-1 and 6 X 10(-7) mol X L-1. The data indicate that VIP may be an inhibitory neurotransmitter involved in the nervous control of penile erection.

Lack of vasoactive intestinal polypeptide nerves in esophageal achalasia

Vasoactive intestinal polypeptide-containing nerves were examined in the lower esophagus of control and achalasia patients. The smooth muscle in patients with achalasia had conspicuously fewer vasoactive intestinal polypeptide-immunoreactive nerve fibers than specimens from control patients. Also the concentration of vasoactive intestinal polypeptide in the lower esophagus was much reduced in achalasia. In view of the potent smooth muscle relaxing effects of vasoactive intestinal polypeptide, it is suggested that the reduced number of vasoactive intestinal polypeptide fibers in the achalasic esophagus causes or at least contributes to the incomplete relaxation and the increased resting tone of the lower esophageal sphincter characteristic of this disease.

An immunohistochemical investigation of vasoactive intestinal polypeptide in the colon of patients with Hirschsprung's disease

The distribution of vasoactive intestinal polypeptide (VIP) in the colon of patients with Hirschsprung's disease was investigated by the peroxidase-antiperoxidase (PAP) immunohistochemical method. Three colonic segments, ganglionic, oligoganglionic and aganglionic, were stained by the unlabeled antibody enzyme method. VIP immunoreactive nerve cell bodies, nerve fibers and nerve endings were distributed throughout the ganglionic and oligoganglionic segments. In contrast, the aganglionic segment contained no VIP nerve endings and the number of fibers was reduced. These differences are thought to be a cause of construction of the colon in Hirschsprung's disease and VIP neurons are therefore believed to participate in the relaxatiion of smooth muscle.

Vasoactive Intestinal Polypeptidergic Nerves and Brunner's Gland Secretion in the Rat

Vasoactive intestinal polypeptide is known to have powerful effect on the secretions from endocrine and exocrine glands. By immunohistochemical studies on the rat, both a dense network of vasoactive intestinal polypeptide-immunoreactive nerve fibers around the acini of Brunner's glands, and small ganglia with vasoactive intestinal polypeptide-immunoreactive nerve-cell bodies close to the glands were demonstrated. Intravenous infusions of vasoactive intestinal polypeptide in doses of 10, 100, and 1000 ng/kg.h significantly increased flow rate, as well as bicarbonate and protein output from Brunner's glands in the rat. After infusion of vasoactive intestinal polypeptide the secretory cells, which in the control group were rich in PAS-positive mucin, became almost completely PAS-negative. It is suggested that physiologic secretion from Brunner's glands may be stimulated by the vasoactive intestinal polypeptidergic nerves.