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PubMed1994

Developmental changes of DNA methylation pattern of embryonic chick pepsinogen gene.

Embryonic chick pepsinogen (ECPg) is one of the pepsinogen isozymogens and its expression is restricted to epithelial cells of the embryonic chick proventriculus (glandular stomach). To examine whether DNA methylation is involved in the regulation of organ-specific and developmental stage-specific expression of ECPg gene, we analyzed the extent of methylation of ECPg gene in normal embryonic and hatched chick organs using methylation-sensitive restriction enzymes. In the proventriculus some CCGG sites underwent demethylation in the gene region after the onset of transcription of the ECPg gene. By contrast, these sites were kept methylated throughout the development in the other organs which do not express ECPg gene. GCGC sites in the gene region became methylated in organs which do not express the ECPg gene, after the initiation of transcription of the ECPg gene in the proventriculus. In the proventriculus, GCGC sites, which were methylated in other organs, were kept unmethylated throughout the development. The methylation state of CpG sites showed no change in the proventriculus of a chick 2 weeks after hatching when the expression of the ECPg gene had completely ceased. The data presented here demonstrate that the DNA methylation is involved in the regulation of organ-specific expression, but stage-specific expression might be brought about by some other mechanisms.

Animals↗

PubMed2003

Filling and emptying of the alimentary tract of meal-fed broiler breeder hens.

For evaluation of the filling and emptying of the alimentary tract, broiler breeder hens were cooped and processed over a 2-d period. Hens were fed at 0600 h on d 1 and after access to feed for 0, 2, 4, and 6 h were placed into coops. Half of the hens from each pen were either immediately processed or were held in coops over-night and processed the following morning, d 2. The alimentary tract was excised from the carcass and then separated and weighed in three segments: the crop, proventriculus and gizzard, and intestines. Hens processed on d 1, after access to feed for only 2 h, had attained maximum intestine weight (176 g), but not until after access to feed for 6 h were peak crop weight (95 g) and peak weight for the proventriculus and gizzard (78 g) attained. Hens processed on d 2 did not differ in crop (12 to 14 g) or intestine (140 to 162 g) weight, but proventriculus and gizzard weights were significantly lower for hens not fed on d 1 prior to cooping (54 g) compared with hens fed on d 1 and cooped after 2, 4, or 6 h (62 to 63 g). However, hens processed on d 2 had proventriculus and gizzard weights that were the same as for those hens processed on d 1 and cooped at 0 h (63 g). Clearance of ingesta from the crop, proventriculus and gizzard, and intestines readily occurred while hens were held overnight without access to water.

Animal Feed↗

PubMed2006

Pharmacological characterization of 5-hydroxytryptamine-induced contraction in the chicken gastrointestinal tract.

5-Hydroxytryptamine (5-HT) receptor subtypes involved in 5-HT-induced contraction of the chicken gastrointestinal tract were characterized pharmacologically using subtype-selective agonists and antagonists. The proventriculus (area of stomach adjacent to the oesophagus) and ileum are examined. 5-HT applied cumulatively caused sustained contraction of the proventriculus that was not decreased by tetrodotoxin, atropine or l-nitro-arginine methylester (l-NAME). alpha-Methyl-5-HT showed the same potency as that of 5-HT, indicating the involvement of the 5-HT(2) receptor. (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane (DOI), 5-methoxytryptamine and 1-(3-chlorophenyl)piperazine hydrochloride (mCPP) were potent, and 2-methyl-5-HT, 5-carboxamidotryptamine, BW723C86 and 6-chloro-2-(1-piperazinyl)pyrazine hydrochloride (MK212) were moderate, but (+/-)-8-hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT), [endo-N-8-methyl-8-azabicyclo-(3,2,1)oct-3-yl]-2,3-dihydro-(1-methyl)ethyl-2-oxo-1H-benzimidazol-1-carboxamide (BIMU-8) and cisapride were weak agonists. Correlation of pEC(50) values of these agonists with documented pEC(50) values for 5-HT(2C) receptor was higher than 5-HT(2A) and 5-HT(2B). Cinanserin, ketanserin, methiothepin, methysergide, mianserin, (8-[5-(2,4-dimethoxy-5-(4-trifluoromethylphenylsulphonamido)phenyl-5-oxopentyl)-1,3,8-triazaspiro[4,5]decane-2,4-dione hydrochloride (RS102221), N-(1-methyl-1H-indolyl-5-yl)-N'-(3-methyl-5-isothiazolyl)urea (SB204741), spiperone and N-desmethylclozapine concentration-dependently inhibited the contractile responses to 5-HT. Correlation of pK(b)/pA(2) of antagonists with documented pK(i) for 5-HT(2C) receptor was highest among 5-HT(2) receptor subtypes. In the methysergide- and ketanserin-treated proventriculus, 5-HT, 2-methyl-5-HT and cisapride did not enhance the electrical field stimulation (5 Hz)-induced cholinergic contractions. 5-HT applied non-cumulatively caused transient contraction of ileum, and the responses were partly decreased by atropine or tetrodotoxin. 5-Methoxytryptamine, alpha-methyl-5-HT, 5-carboxamidotryptamine, L692,247 and DOI were potent agonists. However, 2-methyl-5-HT, cisapride, BW723C86, 8-OH-DPAT and 5-nonyloxytryptamine, mCPP and MK212 were less effective. Ketanserin and methysergide decreased the 5-HT-induced ileal contraction, but neither GR113808 nor SB269970 inhibited the responses. In conclusion, 5-HT causes contraction of the proventriculus via 5-HT(2C)-like receptors present on smooth muscle. 5-HT also causes contraction of the ileum, but the underlying mechanisms are complex, involving neural and smooth muscle components, and both 5-HT(1)- and 5-HT(2)-like receptors. Neural 5-HT receptors similar to 5-HT(3)/5-HT(4) receptors were not found in the chicken proventriculus and ileum.

Anesthetics, Local↗

PubMed1995

Vagal preganglionic neurons innervating the different gastric regions in the Japanese quail (Coturnix japonica).

The cytoarchitecture and distribution patterns of the vagal preganglionic neurons within the dorsal motor nucleus of the vagus nerve (DMNX) innervating the proventriculus and the gizzard of the Japanese quail were examined by Nissl staining and the horseradish peroxidase (HRP) method. A 30% solution of HRP was injected into nine different gastric regions: the ventral and dorsal parts of the proventriculus, the caudodorsal and cranioventral thick muscles, the craniodorsal and caudoventral thin muscles, and the pylorus, and the ventral and dorsal tendons of the gizzard. Nissl preparations showed that the DMNX is composed of two cell groups, the dorsal magnocellular and mediocellular subnucleus (Xd) and the ventral parvicellular subnucleus (Xv). After injection of HRP into the ventral and dorsal parts of the proventriculus, HRP-labeled cells were predominantly observed in the left and right DMNX, respectively. The rostrocaudal distribution patterns of HRP-labeled cells in the Xd and Xv were symmetric on the left and right sides. The distribution patterns of labeled cells following the injection of HRP into each region of the gizzard showed that there was very little difference in the number of neurons between the left and right DMNX, and no topographic localization was found in the Xd and Xv. The vagal preganglionic neurons projecting to the gizzard lay more caudal than the ones for the proventriculus. This study suggested topographic localization in the distribution patterns of the vagal preganglionic neurons innervating the proventriculus and the gizzard.

Animals↗

PubMed1995

The effect of dietary copper sulfate on infectious proventriculitis.

Oral inoculation of day-old broiler chicks with a crude homogenate of affected proventricular tissue, or the same homogenate filtered through a .2 micron filter caused proventricular lesions similar to those responsible for carcass contamination of broilers at processing. Dietary copper sulfate (CUS) has also been shown to produce similar lesions. In this study, we investigated the interaction between crude proventriculus homogenate or filtered proventriculus homogenate and 1 g/kg CUS added to a standard chicken diet. Cobb x Cobb female broiler chicks were distributed into six groups with four replicate battery pens per group. Birds were fed either a standard broiler starter diet or the same diet with 1 g/kg CUS. Each dietary treatment was inoculated per os with 1 mL of either sterile saline, unfiltered homogenate, or filtered homogenate. Both crude and filtered homogenates had a much stronger affect on proventriculus score than did Cu by itself, resulting in no interaction between either homogenate or filtrate and CUS. There was a significant and possibly antagonistic interaction on proventriculus relative weights in the CUS by filtrate group during Week 1 and a synergistic interaction in the CUS by homogenate group during Week 4. Body weights were decreased in birds fed homogenate or CUS, but not in birds fed filtrate. There was a protective effect shown by filtrate on body weight of birds fed both filtrate and CUS only during Week 1. There was a synergistic decrease in body weight of birds fed homogenate and CUS during Week 2. Overall feed conversion efficiency was significantly decreased in the homogenate treatment (P = .04) and decreased in the birds fed CUS (P = .1). There was a (4.2 vs 2.3) (P = .1) decrease in feed conversion efficiency in birds fed both homogenate and CUS. Natural exposure to low levels of the infectious agent present in the homogenates may interact with excess dietary CUS, resulting in increased proventriculus size and decrease in body weight and feed conversion efficiency.

Animals↗

PubMed1990

The ontogeny and distribution of glucagon- and pancreatic polypeptide-immunoreactive cells in the gastrointestinal tract of the chicken.

The times of first appearance and the distribution of APP- and glucagon-immunoreactive cells have been established in the embryonic chick gut between 11 days of incubation and hatching. These immunoreactive cell types appeared for the first time at 13 days of incubation, APP-immunoreactive cells in the duodenum and upper ileum and glucagon-immunoreactive cells in the proventriculus and duodenum. At 14 days, APP-immunoreactive cells were detected in the proventriculus and lower ileum and glucagon-immunoreactive cells in the pyloric region, upper and lower ileum. Thereafter both APP- and glucagon-immunoreactive cells increased in frequency until the numbers at hatching were approximated, APP-immunoreactive cells at 19 days and glucagon immunoreactive cells at 17 1/2 days of incubation. No APP- or glucagon-immunoreactive cells were found in the gizzard, caecum or rectum at any of the selected stages examined. When these types of endocrine cells first appeared, the surface epithelium of the gastrointestinal tract was relatively undifferentiated. A few glands were present in the proventriculus only, at this stage. Thereafter immunoreactive cells of both types were found in the glandular epithelium of the proventriculus, pyloric region and small intestine soon after morphogenesis had begun.

Age Factors↗

PubMed2005

Characterization of turkey and chicken ghrelin genes, and regulation of ghrelin and ghrelin receptor mRNA levels in broiler chickens.

Ghrelin, a peptide hormone produced by the stomach in mammals, stimulates growth hormone release and food intake. Recently, ghrelin was identified and characterized in chicken proventriculus and shown to stimulate growth hormone release but inhibit feed intake. The purpose of this work was to identify and further characterize the ghrelin gene in chickens and in turkeys. Using molecular cloning techniques we have sequenced cDNAs corresponding to chicken (White Leghorn) and turkey ghrelin mRNAs. A total of 844 (chicken) or 869 (turkey) bases including the complete coding regions (CDS), and the 5'- and 3'-untranslated regions (UTRs) were determined. Nucleotide sequence (CDS) predicted a 116 amino acid precursor protein (preproghrelin) for both the chicken and the turkey that demonstrated complete conservation of an N-terminal 'active core' (GSSF) including a serine (position 3 of the mature hormone) known to be a modification (acylation) site important for ghrelin bioactivity. Additional nucleotide sequence was found in the 5'-UTRs of both Leghorn and turkey cDNAs that was not present in broilers or the red jungle fowl. The turkey ghrelin gene, sequenced from genomic DNA templates, contained five exons and four introns, a structure similar to mammalian and chicken ghrelin genes. Ghrelin was highly expressed in proventriculus with much lower levels of expression in other tissues such as pancreas, brain, and intestine. RT-PCR was used to quantify ghrelin mRNA levels relative to 18S rRNA in 3-week-old male broiler chickens. The level of ghrelin mRNA increased in proventriculus in response to fasting but did not decline with subsequent refeeding. Plasma ghrelin levels did not change significantly in response to fasting or refeeding and did not appear to reflect changes in proventriculus ghrelin mRNA levels. Ghrelin mRNA levels declined in broiler pancreas after a 48 h fast and increased upon refeeding. Expression of the gene encoding the receptor for ghrelin (growth hormone secretagogue receptor, GHS-R) and a variant form was detected in a variety of tissues collected from 3-week-old male broiler chickens possibly suggesting autocrine/paracrine effects. These results offer new information about the avian ghrelin and ghrelin receptor genes and the potential role that this system might play in regulating feed intake and energy balance in poultry.

Amino Acid Sequence↗

PubMed2001

Gizzard formation and the role of Bapx1.

The anterior-posterior gut pattern is formed from three broad domains: fore-, mid-, and hindgut that have distinct functional, morphological, and molecular boundaries. The stomach demarcates the posterior boundary of the foregut. Avian stomachs are composed of two chambers: the anterior chamber (proventriculus) and the thick muscular posterior chamber (gizzard). Expression of candidate pattern formation control factors are restricted in the chick stomach regions such that Bmp4 and Wnt5a are not expressed in the gizzard. We previously implicated Bmp4 as controlling growth and differentiation of the gut musculature. Bmp4 is not expressed in the developing gizzard but is expressed in the rest of the gut including the adjacent proventriculus and midgut. Bapx1 (Nkx3.2) is expressed in the gizzard musculature but not in the proventriculus or midgut. We show ectopic expression of Bapx1 in the proventriculus results in a gizzard-like morphology and inhibits the normal proventricular expression of Bmp4 and Wnt5a. Overexpression of a reverse-function Bapx1 construct can result in a small stomach and ectopic extension of Bmp4 and Wnt5a expression into the gizzard. We suggest the role of Bapx1 is to regulate the expression of Bmp4 and Wnt5a to pattern the avian stomach.

Animals↗

PubMed2006

Contractile effects of ghrelin-related peptides on the chicken gastrointestinal tract in vitro.

Ghrelin is an endogenous ligand for growth hormone secretagogue receptor (GHS-R), and it stimulates growth hormone (GH) release, food intake and gastrointestinal motility in mammals. Ghrelin has also been identified in the chicken, but this peptide inhibits food intake in the chicken. We examined the effects of ghrelin and related peptides on contractility of the isolated chicken gastrointestinal tract in vitro. Among ghrelin-related peptides examined (1 microM of rat ghrelin, human ghrelin, chicken ghrelin and growth hormone releasing peptide-6 (GHRP-6)), only chicken ghrelin was effective on contraction of the chicken gastrointestinal tract. Des-acyl chicken ghrelin was ineffective, suggesting that octanoylation at Ser3 residue of chicken ghrelin was essential for inducing the contraction. Amplitude of chicken ghrelin-induced contraction was region-specific: highest in the crop and colon, moderate in the esophagus and proventriculus, and weak in the small intestine. The contractile response to chicken ghrelin in the crop was not affected by tetrodotoxin (TTX), but that in the proventriculus was decreased by TTX and atropine to the same extents. D-Lys3-GHRP-6 (a GHS-R antagonist) caused a transient contraction and inhibited the effect of chicken ghrelin without affecting the high-K+-induced contraction. Chicken ghrelin potentiated electrical field stimulation-induced cholinergic contraction without affecting the responsiveness to bath-applied carbachol in the proventriculus. The location of GHS-R differs in the crop (smooth muscle) and proventriculus (smooth muscle and enteric neurons). These results indicate that ghrelin has contractile activity on gastrointestinal tract in the chicken in vitro, and the effect was region-specific. The action would be mediated through the GHS-R, which is highly sensitive to chicken ghrelin.

Animals↗

PubMed1994

Ontogenesis of some endocrine cells in the duck gastrointestinal tract.

The time of appearance, morphology, and topographic distribution of somatostatin, neurotensin, bombesin, gastrin/CCK and serotonin immunoreactive cells during embryonic development were studied in the duck gastrointestinal tract by immunohistochemical methods. Somatostatin immunoreactive cells first appeared in the duodenum of duck embryos at 9 days of incubation (d.i.). They progressively appeared in the other segments at 19 d.i., and at hatching they were present in all gastrointestinal segments except for the caecum. At hatching, the antrum was the richest region in somatostatin endocrine cells, and the gizzard the poorest. Neurotensin immunoreactive cells were detected at 21 d.i. in the proventriculus, antrum, duodenum, and rectum; at 23 d.i. they were present in all the other segments. Bombesin immunoreactive cells were observed in the proventriculus at 17 d.i., and in the gizzard and antrum at 23 d.i. No cells were detected in the intestinal segments. Gastrin/CCK immunoreactive cells first appeared at 17 d.i. in the antrum region; at 21 d.i. they appeared in the small intestine and around hatching they were found in the other intestinal segments except for the proventriculus and gizzard. Serotonin immunoreactive cells appeared at 21 d.i. in the proventriculus, duodenum, and jejunum-ileum. At 23 d.i., they were present in all other segments. Our results show that the time of appearance of immunoreactive cells may be related to the general development of the gut wall in the duck and may reflect cell differentiation in the mucosa.

Animals↗

PubMed1991

Formation of ganglia in the gut of the chick embryo.

We have examined the formation of myenteric ganglia in the developing avian enteric nervous system. The monoclonal antibody HNK-1 was used to identify neural-crest-derived cells in whole mounts of fore- and midgut of chick embryos. We find that the crest-derived cells extend processes to their neighbors and form a complex network in the wall of the gut. Formation of this network is an unusual behavior of crest-derived cells and suggests the gut microenvironment is critical to this behavior. This cellular network disappears after ablation of the vagal neural crest, indicating the HNK-1-stained cellular network arises from crest-derived cells. The network is found in the gut wall before the vagal nerve fibers are present. This network is first found in the primordium of the proventriculus, distal to the evagination of the lung buds, and progresses just proximal to the yolk stalk at embryonic day (E) 3.5 and almost to the ileocecal junction at E5.5. The number of cells and the complexity of the network decrease in a rostral-caudal direction down the length of the gut at these stages. The leading edge of the network consists of cells serially arranged in longitudinally running strands. The organization of the network changes with increasing embryonic age; we have focused on network changes in the proventriculus. In the primordium of the proventriculus at E3.5, the network consists of a cluster of one or two adjacent crest-derived cells, which extend processes to a number of neighboring crest-derived cells. At E5.5 large increases in the number of cells per cluster and in the length of cellular connectives between clusters are apparent. At E6.5 a crude meshwork of clusters is seen. At E10.5 the arrangement of cell clusters resembles the pattern of ganglia found in the adult myenteric plexus. This network may provide the environmental cues for the differentiation of enteric neurons and a framework for the pattern of ganglia found in the adult enteric nervous system.

Animals↗

PubMed1995

Excitatory action of [Leu13]motilin on the gastrointestinal smooth muscle isolated from the chicken.

The effects of a porcine motilin analogue, [Leu13]motilin (LMT) on the smooth muscle preparations isolated from the chicken gastrointestinal (GI) tract were investigated in vitro. In the proventriculus, LMT (100 nM to 30 microM) caused an atropine-sensitive contraction and enhanced the electrical field stimulation (EFS)- or 1,1-dimethyl-4-phenyl-piperazinium (DMPP)-induced contraction without affecting the response to acetylcholine (ACh). LMT also caused a concentration-dependent contraction of the intestinal tract (duodenum, jejunum, ileum, and colon). The responsiveness to LMT was strongest in the jejunum and weakest in the colon. The responses to LMT in the intestinal segments were not affected by tetrodotoxin, atropine, hexamethonium, pyrilamine, spantide, and 5-hydroxyltryptamine-induced desensitzation, but significantly decreased by verapamil or removal of external Ca2+. LMT did not enhance the EFS- or DMPP-induced contraction in the ileum. Canine motilin also contracted the intestinal segments in a similar concentration range to LMT with an equal potency, but erythromycin A (EMA) and N-ethyl-N-demethyl-8,9-anhydroerythromycin A, 6-9-hemiketal (EM523) showed only a weak contractile activity even at high concentration (up to 100 microM), indicating that motilin receptors in the chicken intestine were somewhat different from those of mammals. In conclusion, LMT produces an excitatory response in the chicken GI tract with a different sensitivity from region to region. The mechanisms of the action were different between the proventriculus and small intestine; that is, LMT contracts the small intestine through the direct action on the smooth muscle cells, but this peptide acts on the enteric cholinergic neurones and stimulates ACh release, and thus regulates autonomic neuroeffector transmission in the proventriculus.

Acetylcholine↗

PubMed1998

Drosophila endoderm development requires a novel homeobox gene which is a target of Wingless and Dpp signalling.

We have identified and cloned a novel type of homeobox gene that is composed of two homeodomains and is expressed in the Drosophila endoderm. Mutant analysis reveals that its activity is required at the foregut/midgut boundary for the development of the proventriculus. This organ regulates food passage from the foregut into the midgut and forms by the infolding of ectoderm and endoderm-derived tissues. The endodermal outer wall structure of the proventriculus is collapsed in the mutants leading to a failure of the ectodermal part to invaginate and build a functional multilayered organ. Lack-of-function and gain-of-function experiments show that the expression of this homeobox gene in the proventriculus endoderm is induced in response to Wingless activity emanating from the ectoderm/endoderm boundary whereas its expression in the central midgut is controlled by Dpp and Wingless signalling emanating from the overlying visceral mesoderm.

Alternative Splicing↗

PubMed2001

Effects of biogenic amines on growth and the incidence of proventricular lesions in broiler chickens.

Biogenic amines have been implicated in a malabsorption syndrome characterized by decreases in feed efficiency and enlargement of the proventriculus. Two studies were conducted to determine the effects of two common biogenic amines, histamine (HIS) and cadaverine (CAD), on broiler growth and the incidence of pathologies associated with proventriculitis. In the first experiment, broiler chicks were fed diets containing 0, 0.01, 0.05, 0.1, and 0.2% HIS, and in the second experiment chicks were fed diets containing 0, 0.1, and 0.2% HIS, 0.1% CAD, or a combination of 0.1% HIS and 0.1% CAD. Histamine at 0.1 and 0.2% or the combination of HIS and CAD (0.1% each) reduced body weight and feed conversion at 21 d of age. Histamine (0.2%) or the combination of 0.1% HIS and 0.1% CAD increased the circumference of the gastric isthmus 14 and 16%, respectively, and the relative weight of the proventriculus by 21 and 36%, respectively. Histamine and CAD increased the total number, incidence, and severity of gizzard erosion and proventricular ulcers (plaques), and decreased the prominence of gastric papillae by 9 to 108%, depending on the lesion and level of biogenic amine. Dietary HIS (0.2%) increased putrescine by 91% and spermidine by 41% in proventriculus, and dietary CAD increased tissue CAD to detectable levels. Analysis of 49 commercially available, animal by-product feedstuffs suggests that if biogenic amines were the singular cause of proventriculitis, the current industry levels of dietary animal protein (5 to 10%) would not compromise growth performance.

Animal Feed↗

PubMed2002

Gastric gross and microscopic lesions caused by the UNAM-97 variant strain of infectious bronchitis virus after the eighth passage in specific pathogen-free chicken embryos.

Herein we report a description of gross and microscopic lesions found in specific pathogen-free chicken embryos caused by UNAM-97 infectious bronchitis virus (IBV) variant strain after the eighth passage. Embryos were divided into three groups and were inoculated in the chorioallantoic sac with 0.2 mL of UNAM-97, Mass 41 IBV (positive control), or sterile PBS (negative control). Forty-eight hours later the allatoic fluid was taken and used to start a cycle of eight passages through 9-d-old embryos. Seven days after the last passage, embryos were harvested and macroscopic lesions in all organs were recorded. Proventriculus and gizzard samples were obtained from all embryos and routinely processed for microscopic and ultrastructural examinations. The UNAM-97 IBV variant strain caused two macroscopic lesions uncommon for Mexican strains: thin-walled proventriculus and gizzard, as well as urate accumulation within an extra-embryonic peritoneal sac, leaving the body through the umbilical duct and accompanied by the yolk sac. At microscopic level, two relevant findings were observed to be produced by this variant. In the proventriculus, there was a decrease in the gland papillary branching, while the gizzard showed a significant reduction in mucosa thickness and tubular-to-proliferative-cell ratio, as well as an absence of hyaline secretion in the lumen. Electrodense material scattered in proventricular and gizzard cells was observed, with a structure consistent with that of coronaviruses. These pathological chicken embryo findings have not been reported as being caused by other IBV strains in Mexico.

Animals↗

PubMed1982

Carbonic anhydrase localization by light and electron microscopy: a comparison of methods.

The histochemical localization of carbonic anhydrase by Hansson's cobalt-salt method was compared with immunocytochemical localization in the proventriculus (glandular stomach), the chorioallantoic membrane, and in articular and growth-plate cartilages from the domestic hen. Numerous differences were observed. Staining was positive by Hansson's method and negative by immunocytochemistry for the submucosal glands of the proventriculus, articular cartilage cells, resting and proliferating cells of the growth plate, nuclei, and intercellular spaces. Red blood cells stained faintly and inconsistently by Hansson's method. Both methods were in agreement for the cytoplasm of the surface mucosal cells of the proventriculus, the cytoplasm of the villus cavity cells in the chorioallantoic membrane, and in hypertrophic cells of growth-plate cartilage. Acetazolamide usually inhibited the histochemical reaction, even in those sites that, according to other methods, did not contain enzyme. Consequently, acetazolamide inhibition appears to be an unreliable control for the histochemical reaction.

Animals↗

PubMed1985

Histochemical detection of glycoproteins in the gastric epithelia of Columba livia.

A histochemical investigation was carried out to detect glycoproteins in the lining and glandular epithelia of 4 regions of the stomach of Columba livia: proventriculus, intermediate region between proventriculus and gizzard, gizzard, intermediate region between gizzard and duodenum. It was noticed the presence of neutral and sulphoglycoproteins, with a clear predominance of the latter in the lining epithelia and in the simple tubular glands of the mucosa of these regions, except for the gizzard. Absence of glycoproteins was noticed in the oxynticopeptic cells of the branched tubular glands of the proventriculus. Neutral glycoproteins and traces of sulphoglycoproteins were present in the lining epithelia of the folds of its central cavity and of its exit duct. Lining the above mentioned structures, the correspondent of the gizzard, inclusively there was a pellicle of sialoglycoproteins.

Animals↗

PubMed1997

Neurochemical coding in the myenteric plexus of the upper gastrointestinal tract of hibernating hamsters.

As part of our investigation of the plasticity of autonomic nerves in physiological and pathological conditions, we have examined the effect of hibernation on the neurochemical content of myenteric nerves and nerve cell bodies of the upper gastrointestinal tract of the non-seasonal hibernator, the golden hamster. Age matched hamsters kept at room temperature and those kept at 5 degrees C but which failed to hibernate, were used as controls. Possible changes in nerve fibres and nerve cell bodies containing the general neuronal marker, protein gene product 9.5, the peptides, vasoactive intestinal polypeptide, substance P (SP) and calcitonin gene-related peptide (CGRP), the catecholamine synthesizing enzyme tyrosine hydroxylase and the enzyme responsible for synthesizing nitric oxide, nitric oxide synthase, were examined in the oesophagus, proventriculus and proximal and distal stomach of the golden hamsters using immunohistochemical techniques. The results of the present study revealed a significant increase in the number of nerve cell bodies and density of nerve fibres containing SP-immunoreactivity and increased number of CGRP-immunoreactive cell bodies but not the other markers examined in the proximal stomach and proventriculus. In contrast, there was no change in the distribution of any of the neuroactive substances examined in the myenteric plexus of the oesophagus and distal stomach. It is suggested that the change in the environment of the hibernating hamsters perturbs the normal digestive physiology in the proximal stomach and proventriculus that is reflected by the selective changes in SP- and CGRP-containing enteric nerves; these changes may be part of protective reflex mechanisms to the environmental changes resulting from hibernation, where upgrading of nerve cell bodies expressing CGRP and SP has occurred.

Animals↗