Immunohistochemical localization of neuropeptides in bovine pancreas

The occurrence and density of distribution of nerves and endocrine cells that are immunoreactive for neuropeptides in the bovine pancreas were studied by immunohistochemistry. The six neuropeptides localized were galanin (GAL), substance P (SP), methionine-enkephalin (MENK), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP). The exocrine pancreas was shown to have an appreciable number of GAL- and SP-immunoreactive nerve fibres but few fibres showing immunoreactivity for VIP and CGRP. Numerous MENK-, GAL-, SP-, and NPY-immunoreactive nerve fibres were seen in the endocrine portion of the pancreas. Nerve cell bodies in the intrapancreatic ganglia showed immunoreactivity for all of the neuropeptides except CGRP. Endocrine cells showing immunoreactivity for GAL and SP were observed in the large islets and islets of Langerhans, respectively. The present results indicate a characteristic distribution of neuropeptides in the bovine pancreas, which may regulate both exocrine and endocrine secretions of pancreas.     

The distribution of nerve fibres immunoreactive for vasoactive intestinal peptide, calcitonin gene-related peptide, substance P and dopamine beta-hydroxylase in the normal equine larynx

The autonomic innervation of the mammalian respiratory system is complex, and involves a wide variety of peptide and non-peptide neurotransmitters which will have an important role in normal laryngeal function and the response to disease. This innervation has been partially described in the horse airway and lung, but there is no information on the equine larynx. This paper describes the expression and distribution of nerve fibres immunoreactive for vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP) and the adrenergic enzymatic marker dopamine beta-hydroxylase (DBetaH) in the mucosa of the equine larynx. The overall relative density of nerve fibres immunoreactive for the different antigens was VIP>CGRP>SP>DBetaH. There were differences in the distribution of nerve fibre types, although each antigen was found in nerve fibres adjacent to blood vessels and mucous glands. VIP -like immunoreactivity (VIP -Li) was particularly extensive in association with mucous glands. SP - and CGRP -like immunoreactivity (SP -Li, CGRP -Li) were also seen close to the epithelium, with occasional nerve fibres coursing beneath and between the epithelial cells. Fragments of SP -Li and CGRP -Li fibres were also present in large nerve fibre bundles and ganglionic cell clusters, but not in the neurons themselves. The density of nerve fibres immunoreactive for DBetaH was very low and restricted to blood vessels and mucous glands. There was marked variation in the density of nerve fibres at the different sites, with the greatest density, particularly for VIP, over the arytenoid cartilage. Immunoreactive nerve fibres were less plentiful over the epiglottis, and the density of all types of nerve fibres was low over the cricoid cartilage. Overall VIP -Li nerve fibres were the most plentiful.     

Immunohistochemical study on the expressions of neuropeptides in the superficial and deep gland of the third eyelid of pigs

The superficial gland of the third eyelid (SGTE) and deep gland of the third eyelid (DGTE) are classified as accessory lacrimal glands. The aim of the present study was to immunohistochemically investigate the expression of vasoactive intestinal peptide (VIP), dopamine beta-hydroxylase (DβH), substance P (SP), galanin, neuropeptide Y (NPY), pituitary adenylate cyclase-activating peptide (PACAP), somatostatin and calcitonin gene-related peptide (CGRP) in the porcine SGTE and DGTE. We demonstrated the distribution patterns of VIP, DβH, SP, NPY and galanin in the nerve fibres in the SGTE and DGTE. None of somatostatin-, PACAP- and CGRP-immunoreactive (IR) nerve fibres were found in the SGTE and DGTE. The majority of VIP- and DβH-IR nerves fibres were found near to glandular acini, tubules, secretory ducts and blood vessels in the SGTE and DGTE. VIP-IR nerve fibres were found in external connective tissue in SGTE and DGTE and only in interlobular connective tissue in the SGTE. DβH-IR nerve fibres were found in interlobular and external connective tissue in the DGTE but not in the SGTE. Single galanin-, SP- and NPY-IR nerve fibres were observed in close proximity to acini and tubules in the SGTE and DGTE. Single galanin-, SP-, NPY-IR nerve fibres were found in close proximity to the secretory ducts in the DGTE, however only SP-IR nerve fibres were found near to the secretory ducts in SGTE. In conclusion, our research aims to highlight some aspects of SGTE and DGTE innervation in pigs and may also be a source of basic knowledge for further studies.     

Immunohistochemical study of the otic ganglion in the pig

The presence of choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), galanin (GAL), substance P (SP) and calcitonin gene-related peptide (CGRP) was studied in neurons and nerve fibers of the porcine otic ganglion. ChAT-positive neurons were very numerous while VAChT-positive nerve cells were moderate in number. The number of neurons containing NPY and VIP was lower and those containing SOM, GAL, SP or CGRP were observed as scarce, or single nerve cells. The above mentioned substances (except SOM) were present in nerve fibers of the ganglion. ChAT- and VAChT-positive nerve fibers were numerous, while the number of nerve terminals containing NPY, VIP and SP was lower. GAL- and CGRP-positive nerve fibers were scarce.     

Analysis of the chemical coding of neurons in the intermediate thoracic ganglion of the pig

The pig has been widely used as a model in cardiovascular research. A unique feature of the porcine extrinsic sympathetic cardiac nerves is that they arise from intermediate ganglia in the thoracic cavity. The localization and pattern of distribution of nerve cell bodies and fibers containing tyrosine hydroxylase (TH), dopamine B-hydroxylase (DBH), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), galanin (GAL), methionine-enkephalin (MET) as well as calcitonin gene-related peptide (CGRP), substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was studied with immunohistochemistry. Almost all the neurons showed immunoreactivity to TH. Immunoreactivity to NPY, VIP, SOM, GAL, MET and PACAP was displayed by nerve cell bodies while nerve fibers exhibited immunoreactivity to all the neuropeptides studied. Therefore, it seems that the chemical coding of neurons and especially nerve fibers in the porcine intermediate ganglion share general similarities (with certain neurochemical variability), with porcine prevertebral ganglia (e.g., celiacomesenteric and caudal mesenteric ganglia).     

Peptidergic and nitrergic innervation of the pineal gland in the domestic pig: an immunohistochemical study

The presence and co-localization of vasoactive intestinal polypeptide (VIP), peptide N-terminal histidine C-terminal isoleucine (PHI), pituitary adenylate cyclase-activating peptide (PACAP), somatostatin (SOM), calcitonin gene-related peptide (CGRP), substance P (SP) and the neuronal isoform of nitric oxide synthase (NOS) were studied in neuronal structures of the pig pineal gland. Paraformaldehyde-fixed pineals of 3-month-old gilts were sliced into serial cryostat sections, which were subjected to a set of double immunofluorescence stainings. Based on the co-existence patterns of neuropeptides, five populations of nerve fibres supplying the pig pineal were distinguished: (1) PHI-positive, (2) PACAP-positive, (3) SOM-positive, (4) SP/CGRP-positive and (5) SP-positive/CGRP-negative. Only a subpopulation of PHI-positive fibres contained VIP at the level detectable by immunofluorescence. NOS was found in some intrapineal PHI- and VIP-positive fibres. PHI-, VIP- and NOS-positive nerve fibres were more numerous in the peripheral than in the central part of the pineal. PACAP-positive fibres were equally distributed within the gland. The density of SOM-positive fibres was higher in the ventro-proximal than in the dorso-distal part of the pineal. SOM was also detected in some neuronal-like cells or specialized pinealocytes situated in the central region of the gland. Two populations of fibres containing SP were found: CGRP-positive, present in the distal and central parts of the pineal as well as CGRP-negative, localized in the proximal compartment of the gland.     

Immunohistochemical characterization of neurons in the porcine ciliary ganglion

The present study was aimed at disclosing the chemical coding of nerve structures in the porcine ciliary ganglion (CG) using immunohistochemical methods. The substances under investigation included markers of "classical" neurotransmitters, choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DbetaH) as well as neuropeptides, somatostatin (SOM), galanin (GAL), substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Immunoreactivity to ChAT and VAChT was found virtually in all the neuronal somata and in numerous intraganglionic, varicose nerve fibres which often formed basket-like formations around the nerve cell bodies. Many CG neurons contained immunoreactivity for SOM (46%) or GAL (29%). Interestingly, a small number (approx. 1%) of the cholinergic somata stained for TH but not for DbetaH; nevertheless, some extra- and intraganglionic nerve fibres displayed immunoreactivity for DbetaH or TH. The CG perikarya stained neither for vasoactive intestinal polypeptide (VIP) nor for neuropeptide Y (NPY), but some NPY- or VIP-positive nerve terminals were observed within nerve bundles distributed outside the ganglion. SP- and CGRP-immunoreactivity was found in some intraganglionic nerve fibres only. The present study revealed that the porcine CG consists of cholinergic neurons many of which contain SOM and GAL. Thus, it can be assumed that in the pig, these neuropeptides are involved, complementary to acetylocholine, in the parasympathetic postganglionic nerve pathway to structures of the eye including the ciliary and iris sphincter muscles.     

Tyrosine hydroxylase- and neuropeptides-immunoreactive nerves in canine trachea

OBJECTIVE: To determine distribution of catecholaminergic and peptidergic nerve fibers in canine tracheas by use of immunohistochemistry. SAMPLE POPULATION: 10 tracheas collected from healthy adult dogs after euthanasia. PROCEDURE: Structure of the nerve network and distribution of tyrosine hydroxylase (TH)- and 6 types of neuropeptide-containing nerves in canine tracheas were immunohistochemically studied, using neurochemical markers. RESULTS: Intraepithelial free nerve endings with immunoreactivity for calcitonin gene-related peptide (CGRP) and substance P (SP) were observed.Tyrosine hydroxylase-, SP-, vasoactive intestinal peptide (VIP)-, and galanin (GAL)-immunoreactive nerve fibers were observed within and around the submucosal seromucous gland. In the smooth muscle layer, numerous TH- and GAL-immunoreactive nerve fibers, a moderate number of VIP- and neuropeptide Y (NPY)-immunoreactive nerve fibers, and a few SP- and methionine enkephalin (ENK)-immunoreactive nerve fibers were observed. Numerous nerve cell bodies with VIP and GAL immunoreactivity and a few with SP ENK, and NPY immunoreactivity were observed. Many TH-immunoreactive fibers were arranged in a meshwork around blood vessels. Nerves with CGRP-, SP-, VIP-, GAL-, ENK-, and NPY-immunoreactivity were also observed around blood vessels. CONCLUSIONS: Complex innervation, including catecholamine- and neuropeptide-containing nerves, which may be related to regulation of muscle contraction and glandular secretion, are found in canine tracheas.     

Immunohistochemical Study of Peptide-containing Nerves in the Gastrointestinal Tract of the Japanese Field Vole, Microtus montebelli

The distribution and relative frequency of nerves containing immunoreactivity for substance P (SP), vasoactive intestinal polypeptide (VIP), gastrin-releasing polypeptide (GRP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and menthionine-enkephalin (MENK) were studied by immunohistochemistry in the gastrointestinal tract of the herbivorous Japanese field vole, Microtus montebelli.     

Immunohistochemical study of the pre- and postnatal innervation of the dog lower urinary tract: morphological aspects at the basis of the consolidation of the micturition reflex

Immunohistochemical studies were performed on male and female bladder and urethra collected from 4 adults dogs and 10 foetal specimens with crown-rump length from 53 to 155 mm (medium-sized breeds, presumptive 38 days of gestation to term). A panel of antisera was tested, including PGP 9.5 to describe the general intramural innervation, ChAT and TH to depict the cholinergic and nor-adrenergic components and NOS1, CGRP, SP, NPY, VIP, SOM, GAL, 5-HT to investigate the possible nitrergic, peptidergic and aminergic ones. A rich cholinergic innervation was present in adult bladder and urethra, along with a lesser number of adrenergic nerves and a small number of nitrergic ones. Either bladder or urethra received numerous CGRP-, SP-, NPY-, VIP-containing nerve fibres which were distributed throughout the muscle layers. All over the lower urinary tract strong to weak ChAT-, CGRP-, SP- and NPY-immunoreactivity was detected in intramural ganglia, in peripheral nerve bundles and around blood vessels. 5-HT-immunoreactive endocrine cells were present in the urethral epithelium. Early foetal organs were supplied only by cholinergic nerve fibres. Few NOS-, CGRP- and SP-ergic components appeared at the end of pregnancy. It can be guessed that sensory mediators such as CGRP and SP increase in postnatal ages while other neuropeptides, such as NPY and VIP, appear only after birth, as the urinary reflex consolidates.     

神经内分泌细胞在鸭胸腺中的表达特征

应用免疫组化技术并结合图像分析软件研究了β-内啡肽、胃泌素、胰高血糖素、5-羟色胺、血管活性肠肽、神经肽Y、生长抑素细胞在鸭胸腺中的表达特征。结果显示：7种神经内分泌细胞在胸腺中呈强阳性表达;β-内啡肽阳性细胞在皮质部较多,而胃泌素、胰高血糖素、5-羟色胺、血管活性肠肽、神经肽Y、生长抑素阳性细胞在髓质和皮髓质交界区的数量高于皮质部;除胰高血糖素外,其余6种神经内分泌激素在胸腺小体中呈不同程度的阳性反应。本试验结果说明,鸭胸腺不仅是中枢免疫器官,而且具有重要的神经内分泌功能;β-内啡肽阳性细胞在T淋巴细胞的发育中发挥重要作用;胃泌素、胰高血糖素、5-羟色胺、生长抑素、血管活性肠肽、神经肽Y阳性细胞在髓质部和皮髓质交界区的表达有利于其通过内分泌、自分泌或旁分泌方式调节T细胞的发育。同时,也探讨了胸腺小体的功能。     

Expression of vasoactive intestinal peptide, calcitonin gene-related peptide, substance P, and intermediate neurofilaments in nasal mucosal nerve fibers of horses without nasal disease

OBJECTIVE: To determine the distribution of nerve fibers containing calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and intermediate neurofilaments in nasal mucosa of horses. ANIMALS: 6 horses without evidence of nasal disease. PROCEDURE: Full-thickness nasal tissue specimens were obtained from the rostral portion of the nasal septum at necropsy, and fluorescence immunohistochemistry was performed to assess mucosal distribution of nerve fibers. RESULTS: Nerve fibers with CGRP-like immunoreactivity (CGRP-Li) formed a dense subepithelial network, and a large number of fibers were found coursing between epithelial cells. Fibers with CGRP-Li were also associated with blood vessels and mucous glands. Fibers with SP-like immunoreactivity (SP-Li) had a similar distribution and density. In contrast, there were few fibers with VIP-like immunoreactivity. Fibers containing intermediate neurofilaments were prominent and appeared as large nerve fiber bundles mainly adjacent to the nasal septum but also close to mucous glands and within the lamina propria. Intermediate neurofilaments were also identified in single nerve fibers at all sites, but the density of fibers with intermediate neurofilaments did not match that of fibers with CGRP- or SP-Li. CONCLUSIONS: The density and distribution of nerve fibers containing SP- or CGRP-Li in nasal mucosa of horses was similar to that reported for other species. However, expression of VIP in nerve fibers was low. Antibodies against intermediate neurofilaments identified many nerve fibers in nasal mucosa of horses but did not appear to identify small diameter fibers expressing SP or VIP.     

Expression of neuronal nitric oxide synthase in the pancreas of the sheep

In numerous mammals, nitric oxide (NO) influences the activity of the exocrine and endocrine pancreas. In this study, immunocytochemistry was utilized to investigate the expression of neuronal nitric oxide synthase (nNOS) in the pancreas of sheep. In double immunocytochemical staining, the co-localization of nNOS with vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) or substance P (SP) was studied. The presence of nNOS was confined to the intrapancreatic neurones (9.6 +/- 1.3%) as well as to nerve fibres of the endocrine pancreas and intrapancreatic ganglia. nNOS-immunoreactive (IR) neurones were round and oval in shape and predominantly (83.3 +/- 2.6%) belonged to the middle-size group (25-50 mum). Numerous, fine islets supplying nNOS-IR nerve terminals were devoid of VIP, SP or NPY. Moderately numerous, non-varicose nNOS-IR nerve fibres of intrapancreatic ganglia frequently expressed VIP or NPY, but not SP; 2.2 +/- 0.6% of nNOS-IR intrapancreatic neurones displayed lack of VIP, whereas 7.5 +/- 0.8% were VIP-IR. All nNOS-IR neurones were devoid of SP. The frequencies of nNOS-IR/NPY-IR and nNOS-IR/NPY-negative intrapancreatic neurones were 2.2 +/- 0.4% and 6.1 +/- 1.1%, respectively. Comparison with other mammals indicated that nitrergic innervation of the ovine pancreas is species-determined and may be a reflection of the ruminants' digestion specificity. The possible origin of nNOS-IR nerve fibres and functional significance of NO in the pancreas of sheep were discussed.     

Immunohistochemical Characterization of Neurones in the Hypoglossal Nucleus of the Pig

With 4 figures and 1 table In this study, the presence of several neurotransmitters and transmitter synthesizing enzymes was studied in hypoglossal nucleus (HN) of the juvenile (4 months old) female pigs (n = 3). Double‐labeling immunofluorescence revealed neurones expressing cholinacetyltranspherase (ChAT), calcitonin gene‐related peptide (CGRP), nitric oxide synthase (NOS), and somatostatin (SOM). Nerve fibers within HN were ChAT, CGRP, NOS, SOM, substance P (SP), Leu‐5‐enkephalin (Leu‐5‐Enk), ß‐dopamine hydroxylase (DßH), neuropeptide Y (NPY) positive. Virtually all the perikarya contained ChAT, whereas CGRP was present in 47% of the neurones. Nerve cell bodies containing NOS or SOM were only occasionally observed. Immunoreactive nerve fibers were found in a close vicinity of the perikarya, often forming baskets around nerve cell bodies. The results obtained were compared with similar data obtained in other species. The presence of immunoreactive structures, origin of the nerve fibers, and functional significance of the findings are discussed.     

Immunocytochemistry of canine thyroid tumors.

Immunocytochemical studies using the peroxidase-antiperoxidase method with commercial antibodies against thyroglobulin, calcitonin, calcitonin gene-related peptide (CGRP), neuron specific enolase (NSE), somatostatin, and neurotensin were performed on 38 Bouin-fixed, paraffin-embedded canine thyroid tumors obtained from necropsy and surgical files from 2 Ecoles Nationales Vétérinaires (Alfort and Nantes, France) and from the Laboratoire d'Histo-Cytopathologie Vétérinaire, Maisons-Alfort (France). The tumors consisted of two follicular adenomas, nine follicular carcinomas, nine solid carcinomas, 12 follicular-compact-cellular carcinomas, and six C-cell carcinomas. All 32 follicular-cell tumors were stained positively for thyroglobulin, half of them had weak to moderate positive immunoreactivity for NSE, and all histologic patterns were represented. They had no immunoreactivity for somatostatin or neurotensin. Four C-cell carcinomas had a solid alveolar pattern, while two had a pseudo follicular pattern characterized by uneven, often coalescent, pseudo-follicular formations with a multilayered epithelium surrounding a cavity that often contained red blood cells. Four C-cell carcinomas had uneven immunoreactivity for calcitonin, while all six were positive for CGRP or NSE. Immunoreactivity for CGRP was stronger or more widespread than positivity for calcitonin when both occurred in the same tumor. Some cells of three C-cell carcinomas had positive immunoreactivity for somatostatin. No immunoreactivity for neurotensin was detected. Seven tumors of follicular cell origin contained a few cells positive for calcitonin or CGRP, while three C-cell carcinomas had a few cells positive for thyroglobulin. These tumors were considered to contain entrapped remnants of normal thyroid tissue rather than being dual hormone producing tumors.     

Noradrenergic and cholinergic innervation of the accessory sexual glands in male sheep

Immunohistochemistry was applied to determine the distribution patterns of nerve fibres containing tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) and vesicular acetylcholine transporter (VAChT) in the prostate, seminal vesicle (SV) and bulbourethral glands (BU) of male sheep. In all organs studied, cholinergic innervation was more developed than noradrenergic innervation. Numerous VAChT-immunoreactive (IR) nerve fibres were found in the muscular layer and mucosa of the SV and BU as well as in the prostate. A similar abundance of noradrenergic nerve fibres (showing immunoreactivity both to TH and DbetaH) was also found in both layers of the SV and BU (but not in the prostate). In the prostate a moderate density of VIP-IR nerve fibres was present but only very scarce NPY-IR nerve fibres were shown. All the studied accessory sexual glands (ASG) of male sheep contained VIP-IR nerve fibres in a similar frequency. Double immunohistochemistry revealed that the vast majority of noradrenergic nerve fibres also contained NPY. None of the noradrenergic nerve fibres showed the presence of VAChT or VIP. The possible functional significance of these findings is discussed.     

A light microscopic and immunocytochemical study of the gastrointestinal tract of the ostrich (Struthio camelus L.)

Although the histological features and endocrine cells of the gastro-intestinal tract of the chicken have been well studied, little is known about these features of the gut of the ostrich. The present study was undertaken to elucidate the histology and peptide-storing endocrine cells of the ostrich. As a rule the histological features of the gastro-intestinal tract of the ostrich corresponded to that of the fowl. However, certain differences were observed. The superficial proventricular glands were simple, branched tubular glands, while the deep proventricular glands were restricted to a slipper-shaped area and extended into the muscularis mucosae. The gizzard had a variably developed muscularis mucosae, a feature that seems to be unique to the ostrich. The villi of the small intestine were long and branched profusely, forming a labyrinthine surface. No Paneth cells were observed. The mucosa of the ceca and the first part of the rectum was thrown in large circular folds, forming a compressed spiral. Numerous melanocytes were seen in the submucosa and the connective tissue around the bloodvessels of the muscle layers at the tips of the ceca. A well developed subserosa was present throughout the gastro-intestinal tract. Endocrine cells immunoreactive to somatostatin, glucagon, gastrin, bombesin, neurotensin, substance P and pancreatic polypeptide were detected in the gastro-intestinal tract of the ostrich. The topographical distribution of those endocrine cells immunoreactive to glucagon, bombesin, neurotensin and substance P differed from that of the chicken. The results of this investigation inferred that at least one of the gut peptides of the ostrich (secretin) to be structurally different from its counterparts in mammal and chicken. Molecular heterogeneity of somatostatin was observed in endocrine cells situated in the deep ventricular glands of the ostrich.     

The influence of experimental ileitis on the neuropeptide coding of enteric neurons in the pig

In the present study, both the ELISA test and immunohistochemical staining were used to investigate the influence of artificially induced ileitis on the chemical coding of enteric neurons in the pig. The ileum wall in experimental (E) pigs was injected in multiple sites with 4% paraformaldehyde to induce inflammation, while in the control (C) animals, the organ was injected with 0.1M phosphate buffer (pH 7.4). Three days after ileitis induction, samples of ileum wall from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM concentration (ELISA test) and the expression of these biologically active substances by the enteric neurons (immunohistochemical staining). Quantitative results showed that ileitis decreased tissue concentration of VIP, CGRP and SOM but increased tissue concentration of SP, NPY and GAL. Immunochemistry revealed that in both the experimental and control pigs, VIP-positive (VIP+) nerve fibers supplied mainly ileal blood vessels, and the labeled pericarya were located in the inner (ISP) and outer submucous plexus (OSP). SP+ and CGRP+ nerve terminals were found in both the mucous and muscular membrane, while the labeled pericarya were found in ISP, OSP and myenteric plexus (MP). In both C and E pigs, the very few nerve terminals containing NPY and SOM were located mainly in the mucous membrane. NPY- or/and SOM-immunopositive nerve cell bodies were found in ISP, OSP and MP. GAL+ nerve fibers supplied all layers of the ileum and were most numerous in the muscular membrane, while the labeled pericarya were present in all the enteric plexuses. The present results suggest that enteric neurons are highly plastic in their response to inflammation.     

Immunohistochemical study on the distribution of endocrine cells in the gastrointestinal tract of the babirusa, Babyrousa babyrussa (Suidae)

The distribution and relative frequency of endocrine cells in the gastrointestinal tract of the babirusa were studied immunohistochemically using the avidin-biotin-peroxidase complex method. Thirteen types of gut endocrine cells were detected; they were immunoreactive for chromogranin, serotonin, somatostatin, gastrin, bovine pancreatic polypeptide (BPP), glucagon, secretin, cholecystokinin (CCK), methionine-enkephalin-Arg6-Gly7-Leu8 (MENK8), motilin, gastric inhibitory polypeptide (GIP) and peptide tyrosine tyrosine (PYY). Cells that were immunoreactive for chromogranin, serotonin, somatostatin and glucagon were found in all portions of the gastrointestinal tract. MENK8-immunoreactive cells were observed in the stomach and small intestine. Gastrin-immunoreactive cells were detected in the pyloric region and duodenum. PYY-immunoreactive cells were found in the small and large intestine. Cells immunoreactive for motilin, CCK, GIP, and secretin were observed in the proximal small intestine and those immunoreactive for neurotensin were found only in the ileum. Although the distribution pattern of endocrine cells in the gastrointestinal tract of babirusa was similar to those reported for pig, restricted distribution of several endocrine cells, gastrin, BPP, MENK8, motilin, CCK, GIP, secretin and neurotensin and wider distribution of glucagon and PYY were observed in the babirusa. The unexpected presence of MENK8 in all glandular regions of the stomach and PYY in the small intestine was also noted. The distribution of gut endocrine cells might be related to the regulatory characteristics of the babirusa digestive tract.