Abnormalities of peptide-containing nerve fibers in infantile hypertrophic pyloric stenosis

The distributions of nerve cells and fibers with immunoreactivity for the peptides enkephalin, gastrin-releasing peptide, neuropeptide Y, somatostatin, substance P, and vasoactive intestinal peptide were examined in specimens of myenteric plexus and external muscle from the pylorus of 20 infants with hypertrophic pyloric stenosis. These were compared with peptide distributions in pyloric samples from unaffected infants and adults. In the normal pylorus the circular muscle was richly supplied with fibers reactive for enkephalin, neuropeptide Y, substance P, and vasoactive intestinal peptide. In pyloric stenosis, these immunoreactive fiber bundles were either missing or less than 5% of normal. In contrast, there were reactive cell bodies and nerve fibers in the myenteric plexuses of both normal and affected specimens. In the samples from cases of stenosis, swollen nerve fibers that appeared to be in the process of degeneration were frequently encountered. It is concluded that infantile hypertrophic pyloric stenosis is associated with a loss of peptide immunoreactivity in nerve fibers in the circular muscle, although the same peptides are still revealed in fibers and in nerve cell bodies in the myenteric plexus.     

Distribution and coexistence of peptides in nerve fibers of the external muscle of the human gastrointestinal tract

The nerve fibers that supply the external muscle of the human gastrointestinal tract were examined for their immunoreactivity to the neuropeptides enkephalin, neuropeptide Y, somatostatin, substance P, and vasoactive intestinal peptide, for tyrosine hydroxylase (a catecholamine-synthesizing enzyme), and for coexistence between immunoreactivities in nerve fibers. Studies on coexistence revealed that the majority of reactive nerve fibers could be placed in one of two classes: (a) those fibers with reactivity to enkephalin or substance P, or both, and (b) fibers containing one or both of the peptides neuropeptide Y and vasoactive intestinal peptide. Many fibers immunoreactive for vasoactive intestinal peptide or neuropeptide Y, or both, were found throughout the external smooth muscle of the gastrointestinal tract, but neuropeptide Y-reactive fibers were less common in the small and large intestines than in the stomach and esophagus. Fibers immunoreactive for enkephalin or substance P, or both, were sparse in the esophagus, increased in numbers to reach maximal frequency in the pylorus, and maintained a similar frequency in the small and large intestines. Fibers with somatostatin or tyrosine hydroxylase immunoreactivity were rare. In general, sphincter regions were similar to nonsphincter regions in peptide-immunoreactive fiber numbers and types, except that the internal anal sphincter had no enkephalin-immunoreactive fibers and very few substance P-reactive fibers. Moderate numbers of fibers reactive for neuropeptide Y and vasoactive intestinal peptide were found in the internal anal sphincter. It is suggested that enkephalin and substance P are in excitatory fibers and that vasoactive intestinal peptide and neuropeptide Y are in fibers inhibitory to the external muscle.     

Distribution of peptide-containing nerve fibres in achalasia of the oesophagus

In this study the innervation of the normal human oesophagus was compared with samples taken from 12 patients undergoing Heller's cardiomyotomy for achalasia. The distribution of all nerve fibres in the oesophageal wall was revealed by immunoreactivity to neuron specific enolase and subpopulations of nerve fibres were revealed by immunoreactivity to vasoactive intestinal peptide, neuropeptide Y, enkephalin and substance P. In healthy oesophagus, many nerve fibres immunoreactive for vasoactive intestinal peptide and neuropeptide Y were present in the circular and longitudinal muscle layers of the oesophageal wall and in the cardia of the stomach, whereas fibres immunoreactive for enkephalin and substance P were uncommon. Neuropeptide Y-reactive fibres were commonly seen around blood vessels. In the myenteric plexus cell bodies reactive for vasoactive intestinal peptide and neuropeptide Y were prevalent, as were varicose and non-varicose fibres. In contrast, samples from patients with achalasia revealed few nerve fibres immunoreactive for vasoactive intestinal peptide or neuropeptide Y in either circular or longitudinal muscle, suggesting damage to the inhibitory motor neurons to the muscle layers. Very few fibres were found that were reactive for neuron-specific enolase, indicating that other fibre populations (e.g. excitatory cholinergic motor neurons) are also damaged in achalasia. These abnormalities were observed in biopsies from both the constricted and dilated portions of the oesophagus, but the pattern of innervation in the gastric cardia was normal. Myenteric ganglion cells were seen in the oesophagus in only two patients and varicose nerve fibres in the myenteric plexus were uncommon. Neuropeptide Y-reactive perivascular nerve fibres were still found in achalasia as well as non-varicose nerve fibres in the myenteric plexus. These findings indicate damage to all intrinsic neurons in the oesophageal wall in achalasia; however, extrinsic nerve fibres appear to be intact.     

Origins of peptide and norepinephrine nerves in the mucosa of the guinea pig small intestine

Norepinephrine, acetylcholine, and certain peptides are contained in mucosal nerves and have potent effects on transepithelial water and electrolyte fluxes. It is difficult to ascribe roles for these nerves as their sources are unknown. The present studies were undertaken to determine the origins of nerve fibers that are found in the mucosa of the guinea pig small intestine and which contain one of the following substances: vasoactive intestinal peptide, substance P, somatostatin, neuropeptide Y, cholecystokinin, or norepinephrine. Nerve fiber origins were ascertained by making lesions to sever pathways through which the nerves could reach the mucosa. The lesioning operations were homotopic autotransplants of short (2 cm) segments of intestine; myectomies, in which a 5-10-mm length of intestine was stripped of longitudinal muscle and myenteric plexus; and extrinsic denervation, in which nerves reaching the intestine through the mesentery were severed. The results of these studies, considered along with previously published work, led to the upcoming conclusions. Nerve fibers in the mucosa showing immunoreactivity for vasoactive intestinal peptide, somatostatin, cholecystokinin, and neuropeptide Y arise from cell bodies in the overlying submucous plexus. Substance P fibers arise in part from the overlying submucous plexus and in part from the overlying myenteric plexus. Mucosal norepinephrine fibers arise from extrinsic sympathetic ganglia. Enkephalin, gastrin-releasing peptide, and 5-hydroxytryptamine, which are in some enteric nerves, are not found in submucous nerve cells and few, if any, fibers containing these substances supply the mucosa. Thus, the mucosa receives a dense nerve supply, much of which arises locally from submucous ganglia.     

Peptide-containing nerve fibers in the stomach wall of rat and mouse

Peptide-containing nerve fibers were found to be numerous in the glandular stomach of the rat and mouse. The immunoreactive neuropeptides demonstrated included vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), gastrin-releasing peptide (GRP), substance P (SP), enkephalin, somatostatin, cholecystokinin, and neuropeptide Y (NPY). The density and distribution of the various peptide-containing fibers did not differ overtly between the pyloric and oxyntic gland areas except for the GRP fibers, which were fewer in the pyloric than in the oxyntic mucosa. The entire VIP nerve fiber population was found to also contain PHI. Immunoreactive NPY was found to occur in the VIP/PHI fibers (VIP/PHI/NPY fibers) in the smooth muscle and intramural ganglia of both rat and mouse and in the mucosa of the mouse. Mucosal VIP/PHI fibers in the rat did not contain any NPY-like material. Perivascular NPY fibers in both species and mucosal NPY fibers in the rat did not contain VIP or PHI. The mucosa harbored numerous GRP fibers and VIP/PHI (rat) or VIP/PHI/NPY (mouse) fibers, and a modest number of NPY (rat) and SP fibers. In the submucosa the peptide-containing nerve fibers were found mainly in the ganglia and around blood vessels. Blood vessels received a rich supply of NPY fibers; the number of perivascular VIP/PHI, GRP, and SP fibers was much lower by comparison. The smooth muscle and myenteric ganglia harbored not only VIP/PHI/NPY, GRP, and SP fibers but also enkephalin, somatostatin, and cholecystokinin fibers. Gastrin-releasing peptide, VIP/PHI/NPY, SP, and enkephalin nerve cell bodies occurred in the myenteric ganglia. As studied in the rat, vagal denervation did not affect the density and distribution of the various peptide-containing nerve fibers. After sympathectomy, mucosal and perivascular NPY fibers disappeared. The other types of peptide-containing nerve fibers were not affected.     

Distribution and origin of the peripheral innervation of rat cervical esophagus

Several neurotransmitters, neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), galanin, enkephalin, calcitonin-gene related peptide (GGRP), substance P, as well as nitric oxide synthase (NOS), and the noradrenergic marker tyrosine-hydroxylase (TH) were localized by immunocytochemistry in the cervical esophagus of rat. Nerve fibers containing the neuropeptides, NOS, and TH were distributed in the myenteric plexus, around muscle bundles and small blood vessels. Injection of the retrograde tracer True Blue (TB) into the cervical esophagus resulted in the appearance of labeled nerve cell bodies in the superior cervical, the stellate, the nodose, the sphenopalatine, the dorsal root ganglia at levels C₂–C₇, and in local ganglia close to the thyroid. Most of the TB-labeled nerve cell bodies in the superior cervical ganglia contained NPY. In the stellate ganglion, a few labeled nerve cell bodies contained VIP whereas an additional few cell bodies stored NPY. In local ganglia, the majority of labeled cell bodies contained VIP. In the nodose ganglion and cervical dorsal root ganglia, the majority of the labeled nerve cell bodies stored CGRP. The results indicate that the cervical esophagus has a dense innervation with multiple neurotransmitters emanating from several ganglia. As judged by the pattern of nerve fiber distribution, they may regulate esophageal peristalsis and blood flow, some of them possibly in a cooperative manner.     

Migration of the myoelectric complex after interruption of the myenteric plexus: intestinal transection and regeneration of enteric nerves in the guinea pig

The effects of surgical interruption of the myenteric plexus (myectomy), extrinsic denervation of a length of small intestine, or transection and reanastomosis of the intestinal wall on migration of phase III of the migrating myoelectric complex was studied in guinea pigs. In addition, the recovery of phase III migration and the regrowth of intestinal nerves and muscle across the reanastomosis was studied at various times up to 60 days after surgery. At 6-9 days after surgery, phase III did not migrate past the myectomy during 50%-60% of recorded migrating myoelectric complexes and transection and reanastomosis of the intestinal wall blocked aboral progression of phase III in 90% of cases. Extrinsic denervation did not alter phase III migration through the denervated segment. Phase III migration past the reanastomosis recovered with time after surgery; 80% recovery occurred by 60 days after surgery. Immunoreactivities for vasoactive intestinal peptide, gastrin-releasing peptide, and somatostatin were used as markers for intestinal nerves that were cut by transaction. Immunoreactivities for vasoactive intestinal peptide and gastrin-releasing peptide are contained in myenteric neurons that project in an oral to anal direction to other myenteric ganglia and to the circular muscle. Immunoreactivity for somatostatin is contained in nerve fibers projecting aborally to other myenteric ganglia. At 7-15 days after surgery, there were accumulations of immunoreactivities for vasoactive intestinal peptide, gastrin-releasing peptide, and somatostatin in nerve fibers on the oral side of the reanastomosis, but nerve fibers containing these peptides were not observed in myenteric ganglia or circular muscle close to the anal edge. At 23-28 days, immunoreactivities for vasoactive intestinal peptide, gastrin-releasing peptide, and somatostatin nerve fibers were traced across the reanastomosis and nerve terminals were detected in ganglia and muscle close to the lesion on the anal side. Nerve fibers traversed the lesion in all cases at 57-60 days and vasoactive intestinal peptide-, gastrin-releasing peptide-, and somatostatin-immunoreactive nerve terminals were detected in the first two to three rows of myenteric ganglia on the anal side. Regrowth of intestinal muscle followed a similar time-course to that observed for nerves. These data suggest that interruption of the myenteric plexus alone does not completely block phase III migration. In addition, recovery of phase III migration past a reanastomosis is associated with a restoration of both nervous and mechanical connections.     

Peptidergic innervation of the human esophageal smooth muscle

Studies were performed to define the peptidergic nature of intramural nerves in the human esophagus. Cryosections of uninvolved surgically resected tissues from 14 individuals were studied by immunofluorescence for the localization of 10 neuropeptides. Myenteric neurons showed bombesin-, calcitonin gene-related peptide-, galanin-, substance P-, vasoactive intestinal polypeptide-, leucine-enkephalin-, methionine-enkephalin-, neuropeptide Y-, and somatostatin-like immunoreactivity. Submucous neurons had all the above except neuropeptide Y, methionine-enkephalin, leucine-enkephalin, and bombesin. Both groups of neurons received nerve terminations positive for calcitonin gene-related peptide, galanin, neuropeptide Y, substance P, and vasoactive intestinal polypeptide. Myenteric neurons additionally received terminations positive for neuropeptide Y, methionine-enkephalin, and somatostatin. All muscle layers had varicose fibers that reacted for calcitonin gene-related peptide, galanin, neuropeptide Y, and substance P. Longitudinal and circular muscle received few nerves reactive for leucine-enkephalin, whereas methionine-enkephalin was localized in a few nerve endings in the circular muscle. Somatostatin- and bombesin-reactive nerves occurred in longitudinal muscle. No cholecystokinin-reactive nerves were found. This study extends the results of previous studies and shows the previously undescribed presence of calcitonin gene-related peptide- and galanin-reactive nerves in the human esophagus and identifies neuropeptides that may serve as motor, sensory, and modulatory neurotransmitters of esophageal nerves.     

The ontogeny and distribution of neuropeptides in the human fetal and infant esophagus.

The innervation and neuropeptide expression of fetal and infant human esophagus were studied. Esophageal samples (n = 30) from 8 weeks' gestation to 28 months of age were immunostained using antisera to general and specific neuronal antigens, and the results were quantified using computer-assisted image analysis. Nerve protein (protein gene peptide 9.5 and synaptophysin) and glial cell protein (S100) immunoreactivities were present by 8 weeks' gestation in primitive cell bodies and fibers in the outer layers of the esophagus. Immunoreactivity for peptides was first detected in fibers at 11 weeks' gestation in myenteric plexus and at 13 weeks' gestation in muscle. Peptide-immunoreactive cell bodies were not seen until 13-15 weeks. A pattern of immunoreactivity for neuropeptides comparable with that seen in mature neonates and infants was present by 22 weeks of gestational age. The percentage area of protein gene peptide 9.5-immunoreactive and vasoactive intestinal peptide-immunoreactive nerve fibers increased from low levels to 3.68% and 0.27%, respectively, at 13 weeks and peaked at 18 weeks (10.50% and 4.74%). These findings provide a foundation for future research into the contribution of neuropeptides to pediatric esophageal dysmotility.     

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 beta-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 beta-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 beta-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 beta-hydroxylase-, and 5-hydroxytryptamine-containing neurons in the different layers of the submucous plexus is discussed.     

Immunocytochemical study of peptidergic structures in Brunner's glands

Nervous and endocrine peptidergic structures in human Brunner's glands were studied by immunofluorescence. Endocrine cells storing immunoreactive components respectively similar to somatostatin 14, the amino-terminal portion (1-14) of somatostatin 28, gastrin-cholecystokinin, and peptide YY were distributed throughout the acini. Peptidergic nerve structures contained materials immunologically related to vasoactive intestinal peptide, peptide histidine methionine, substance P, neuropeptide Y, and gastrin-releasing peptide. The latter peptide was detected in discrete fibers running into the acini but within no cell body in the submucosa. All other neuropeptides were stored in fibers, isolated or grouped in bundles, and in perikarya of submucosal ganglia close to the acini. No immunoreactive structures were detected using antisera directed against pancreatic polypeptide, secretin, motilin, neurotensin, or calcitonin gene-related peptide. The results suggest that several regulatory peptides may be involved in the control of Brunner's glands in humans.     

Regulatory peptides in lower esophageal sphincter of pig and man

Smooth muscle specimens from the lower esophageal sphincter (LES) region of pig and man were analyzed for vasoactive intestinal peptides (VIP), substance P (SP), enkephalin, neuropeptide Y (NPY), gastrin/cholecystokinin (CCK), neurotensin, and somatostatin using immunocytochemistry and radioimmunoassay. VIP-, SP-, enkephalin-, and NPY-immunoreactive nerve fibers were observed in the LES of both species, whereas nerve fibers containing gastrin/CCK, neurotensin, and somatostatin could not be demonstrated. The peptide-containing nerve fibers occurred in the intramural ganglia and in the smooth muscle layers. There was a rich supply of VIP- and NPY-immunoreactive fibers, whereas the supply of SP- and enkephalin-immunoreactive nerve fibers were moderate in number in both species examined. The concentration of VIP, SP, enkephalin, and NPY was comparable in the two species. The present study shows that the pattern of peptidergic innervation of the LES is similar in pig and man. It is proposed that neuronal VIP, SP, enkephalin, and NPY may serve to modulate the motor activity of the LES and that the pig is a suitable experimental animal for the study of regulatory peptides and LES functions.     

Distribution of immunoreactive substance P in opossum esophagus

We localized immunoreactive substance P and measured its content throughout the opossum esophagus. Substance P-like immunoreactive nerve fibers were more abundant in muscularis mucosae than in the longitudinal smooth muscle layer and more abundant in the latter than in the circular smooth muscle layer. The distribution of substance P-like immunoreactive nerve fibers in the circular muscle layer of the esophagogastric junction was comparable to that of the esophageal body. Immunoreactive fibers were also found on and in arteries, submucosal glands, and epithelium, but none were seen in striated muscle. Both the myenteric and submucous plexuses contained substance P-like immunoreactive nerve cell bodies and processes. In the muscularis propria, the content of substance P-like immunoreactive peptide (pg/mg protein, ¯X±1 SE) in the smooth muscle region of the esophageal body (5.9 ±0.6) exceeded that in the striated muscle region (2.5 ±0.2) and at the esophagogastric junction (1.8±0.5), but the latter two values were similar (P<0.05). Mucosal content of substance P in the region of the esophagogastric junction (1.2±0.1) differed from that of the smooth muscle region of the esophageal body (9.2±2.6) but not (P>0.05) from that of the striated-muscle region (5.9±1.0). The broad distribution and diversity of immunoreactive structures suggest that substance P may have both sensory and motor functions in the esophagus.     

Immunohistochemical study of enteric nervous system after small bowel transplantation in humans

The neurohormonal structures of two human intestines removed due to rejection 22 months and eight months after intestinal transplantation were studied by an indirect immunohistochemical method and compared with normal ileum. The distribution and density of neurons immunoreactive for tyrosine hydroxylase, substance P, calcitonin gene-related peptide, neuropeptide Y, vasoactive intestinal peptide, galanin, gastrin-releasing peptide,l-enkephalin, and somatostatin were examined. Mucosal endocrine cells immunoreactive for somatostatin, peptide YY, and glucagon were also examined. Extrinsic adrenergic fibers and perivascular fibers were absent in all intestinal layers of the failed grafts. The distribution of intrinsic neurons was unchanged; however, the density was decreased by one rank. Distribution of endocrine cells of the first graft was similar to the normal. Extrinsic fibers were not detected by immunohistochemistry in human small intestinal grafts following long-term survival and eventual rejection, while the immunohistochemical expression of intrinsic neural and endocrine transmitters were well preserved.Aided by Research Grants from the Veterans Administration and Project Grant No. DK-29961 from the National Institutes of Health, Bethesda, Maryland.     

Innervation of the upper airways

The respiratory tract has a rich supply of autonomic nerves. Among the neurotransmitter candidates are noradrenaline, neuropeptide Y, substance P, calcitonin-gene-related peptide, gastrin-releasing peptide, acetylcholine, vasoactive intestinal polypeptide, and peptide histidine isoleucine. The fibers are distributed around blood vessels and seromucous glands, and beneath and/or within surface epithelium. The distribution suggests that the fibers may influence blood flow, glandular secretion, and epithelial functions.     

Idiopathic chronic constipation is associated with decreased colonic vasoactive intestinal peptide

To investigate the reported association between idiopathic chronic constipation and morphologic abnormalities of enteric nerves, we measured the concentrations of six neuropeptides, vasoactive intestinal peptide, peptide histidine-methionine, substance P, methionine5-enkephalin, neuropeptide Y, and the bombesinlike intestinal peptides, in descending colon from 4 patients with idiopathic chronic constipation. Decreased concentrations of vasoactive intestinal peptide (707 +/- 112 ng/g wet tissue) and peptide histidine-methionine (543 +/- 58 ng/g) were found in the muscularis externa obtained from constipated patients compared with normal concentrations (40 patients) of vasoactive intestinal peptide (1199 +/- 47 ng/g) and peptide histidine-methionine (815 +/- 45 ng/g). Vasoactive intestinal peptide was identified by immunocytochemistry in nerve fibers within the circular smooth muscle layer of descending colon obtained from 6 control patients, but not in nerve fibers within the circular smooth muscle of descending colon obtained from 3 patients with idiopathic chronic constipation. By contrast, the distribution of immunoreactive met5-enkephalin was similar in normal descending colon and in descending colon obtained from patients with idiopathic chronic constipation. Decreased colonic concentrations of vasoactive intestinal peptide (a candidate nonadrenergic, noncholinergic inhibitory neurotransmitter) may be associated with diminution of inhibitory innervation of colonic circular smooth muscle in some patients with idiopathic chronic constipation.     

Regulatory peptides in the thyroid gland--a review on their localization and function.

It has been demonstrated that nerve fibres storing immunoreactivity of vasoactive intestinal polypeptide, peptide histidine iso-leucine, neuropeptide Y, substance P, calcitonin gene-related peptide, galanin, and cholecystokinin exists in the thyroid, though the content of these neuropeptides is lower in the thyroid than in other organs, like in the gut. Furthermore, the parafollicular C-cells have been shown to harbour several different peptides: calcitonin, somatostatin, calcitonin gene-related peptide, gastrin-releasing peptide, katacalcin and helodermin. In addition, other regulatory peptides like atrial natriuretic hormone, growth factors, and cytokines are also produced in the thyroid. This review summarizes today's knowledge on the effects of these peptides on thyroid hormone secretion and their possible role in thyroid physiology. So far, functional studies have failed to establish any convincing effect of substance P, calcitonin gene-related peptide, galanin and cholecystokinin on basal or TSH-stimulated thyroid hormone secretion. In contrast, vasoactive intestinal peptide has convincingly been demonstrated to stimulate thyroid hormone secretion, and neuropeptide Y to potentiate the inhibitory action of noradrenaline on TSH-induced thyroid hormone secretion. This suggests that these two neuropeptides are involved in the intrathyroidal neural regulation of thyroid function. Moreover, the C-cell peptides somatostatin, calcitonin, calcitonin gene-related peptide, and katacalcin seem to be involved as inhibitors of thyroid hormone secretion, whereas both gastrin-releasing peptide and helodermin stimulate thyroid hormone secretion. Atrial natriuretic hormone and growth factors, and cytokines seem to inhibit thyroid hormone secretion. Hence, studies undertaken so far suggest a local intrathyroidal peptidergic regulatory concept, the exact role of which remains to be established.     

Slow transit chronic constipation (Arbuthnot Lane's disease)

Seven patients (6 women, 1 man) with severe idiopathic chronic constipation, who underwent surgery with subtotal colectomy and ileorectal anastomosis, were investigated for the occurrence and density of nerve fibres, immunoreactive to different neuropeptides in the mucosa, submucosa, ganglia and smooth muscle in fresh specimens from the colon ascendens, the colon transversum and the colon descendens-sigmoideum. The following substances were studied: enkephalin, substance P, somatostatin, neuropeptide Y, vasoactive intestinal polypeptide, calcitonin gene-related peptide, bombesin, motilin, tyrosine hydroxylase, dynorphin and galanin. Nerve fibres immunoreactive to CGRP occurred in large numbers in the myenteric ganglia of the patients with severe idiopathic chronic constipation, whereas in the myenteric ganglia of the control cases they only occurred in low numbers. In two patients there was no detectable motilin immunoreactivity and in one patient only sparse in the mucosa and the smooth muscle. The other neuropeptides investigated occurred in the density and distribution previously reported in the normal gut. With the present technique there were indications that patients with severe idiopathic chronic constipation have a significant difference in the occurrence of immunoreactive nerve fibres to CGRP and motilin compared to control patients.     

Noradrenergic and peptidergic nerves in the synovial membrane of the Sprague-Dawley rat

This immunohistochemical study of nerves in the synovial tissue of Sprague-Dawley rats demonstrated the occurrence of 4 neuropeptides and 2 enzymes that are involved in the synthesis of catecholamines. Substance P and calcitonin gene-related peptide were colocalized in fibers that terminated as varicosal endings in the synoviocyte layer. Similarly, tyrosine hydroxylase and dopamine beta-hydroxylase, which reflect the presence of noradrenaline, were colocalized with neuropeptide Y. These fibers were predominantly found adjacent to and within blood vessel walls. Immunoreactivity to vasoactive intestinal polypeptide was seen in varicose nerve terminals in the synoviocyte layer. Many were localized in vessel walls. There is accumulating evidence of an involvement of substance P and noradrenaline in the pathogenesis of inflammatory joint disease and nociception. The role of these colocalized neuropeptides, namely, calcitonin gene-related peptide and neuropeptide Y, in the pathophysiology of such conditions warrants further analysis.     

Substance P-containing nerves in the human small intestine. Distribution, ultrastructure, and characterization of the immunoreactive peptide

Light and electron microscopic immunocytochemical techniques were used to examine the distribution and ultrastructure of substance P-immunoreactive nerves in human jejunum and distal ileum. The organization of human enteric substance P-containing nerves closely resembled that in other species. Dense arrays of varicose immunofluorescent fibers occurred in myenteric and submucous ganglia (which contained immunoreactive nerve cell bodies) and in the mucosa. There were fibers in both muscle layers, in the muscularis mucosae, and around blood vessels. Fibers in the myenteric plexus contributed to both ascending and descending pathways. Substance P-immunoreactive axon profiles contained small round and large round vesicles and were apposed to nerve cell bodies, and nonimmunoreactive and immunoreactive axon profiles. Synapselike contacts were occasionally observed on nerve cell bodies and processes. The substance P-like material was characterized by high pressure liquid chromatography and radioimmunoassay and found to be indistinguishable from the authentic undecapeptide. These results suggest that enteric nerves containing substance P may play similar roles in humans as in other species.