Development of gastrin-and somatostatin-containing cells in the pyloric gland region of the bovine abomasum

The ontogeny of gastrin- and somatostatin-containing cells in the pyloric gland region of the abomasum was studied in bovine fetuses, newborns and adults, using immunohistochemical techniques. A clear-cut developmental increase in the two kinds of endocrine cells could not be observed. The region of the lesser curvature displays more D and G cells than the greater curvature. Cells of both open and closed types are found from the earliest stages examined and continue to be present throughout the complete differentiation of the pyloric mucosa.     

Immunohistochemical localization of some endocrine cells in the gastroenteropancreatic system of Erinaceus europaeus

The distribution of chromogranin A and neuron specific enolase (NSE) in the neuroendocrine gut system and the morphology and distribution of cells containing gastrin, somatostatin, neurotensin and VIP in the gastroenteropacreatic (GEP) apparatus of Erinaceus europaeus were investigated by immunohistochemical methods. Chromogranin A and somatostatin immunoreactive cells were present throughout the gastrointestinal mucosa, with the exception of the oesophagus and in the pancreas. Gastrin cells were peculiar of the pyloric glands and duodenal mucosa and neurotensin cells of the small intestine. No VIP immunoreactive endocrine cells were noticed in the GEP system. VIP and NSE immunoreactivities were detected both in nerve cell bodies and terminals of the wall of the GEP apparatus. NSE immunoreactivity was found in the endocrine cells of the fundic and pyloric mucosa.     

Apoptosis in Helicobacter pylori gastritis is related to cagA status

BACKGROUND: Helicobacter pylori infection increases gastric epithelial cell apoptosis; however, the influence of cagA status is still controversial. We aimed to investigate if cagA status is related to apoptosis in H. pylori gastritis at different anatomic sites of the gastric mucosa. MATERIALS AND METHODS: We studied by immunohistochemistry (streptavidin-biotin method) pro-apoptotic (Bax and Bak) and antiapoptotic (Bcl-2 and Bcl-x) proteins expression, scored from 0 to 4, in gastric biopsies, at the antrum (lesser and greater curvatures), incisura, and corpus (greater curvature) from 50 patients with H. pylori gastritis (22 males, 28 females, median age 40 years) and eight non-infected patients (6 males, median age 39.6 years). H. pylori and cagA status were determined by polymerase chain reaction. RESULTS: Apoptotic proteins were expressed in a granular pattern, in the cytoplasm of foveolar cells; Bax and Bak expression was higher than Bcl-2 and Bcl-x in most cases and was significantly higher in patients infected by cagA-positive strains than in those infected by cagA-negative strains (p = .001). Bak expression was higher at the lesser curvature (antrum and incisura) than in the other regions (p = .002) and was correlated with atrophy. Anti-apoptotic proteins were significantly more expressed at the antral lesser curvature than in the other regions of the stomach (Bcl-2: p = .02; Bcl-x: p < .001). CONCLUSIONS: Infection with cagA-positive strains is significantly associated with overexpression of pro-apoptotic proteins in the gastric mucosa, mainly at the antral lesser curvature, which may have a role on atrophy development. Anti-apoptotic proteins were also overexpressed at the lesser curvature, which may occur to keep epithelial cell turnover or might be related to malignant transformation.     

Differential distribution of transforming growth factor-alpha immunohistochemistry within whole gastric mucosa in rats

Transforming growth factor-alpha (TGF-alpha) plays an important role in both proliferation and differentiation of mucosal cells at the gastrointestinal level, including stomach, where it is constitutively produced. This study evaluated the immunohistochemical distribution of TGF-alpha within whole gastric mucosa in rats, through the examination of seriate sections. Each stomach was opened along the greater curvature, pinned upon a cork plate, fixed in formalin and cut in 2-mm parallel strips which were sequentially superimposed on a glass slide. Sections were immunostained for TGF-alpha and pictures were taken from three areas: greater and lesser curvature; mucosa lying between the two curvatures. The sections were graded on the basis of the intensity of TGF-alpha staining, which was scored as follows: 0) no staining; 1) weakly positive; 2) intensely positive. The percent number of immunopositive cells and a mean intensity were calculated. Gastric mucosa showed a marked immunopositivity to TGF-alpha, mainly in parietal cells whose cytoplasm displayed moderate to intense staining. Positive cells (and the mean intensity) of total mucosa were 15.7+/-6.1% (1.13+/-0.42). However, they were not uniformly distributed, being 26.3+/-1.9% (1.67+/-0.24) in the mucosa lying between the two curvatures, 12.4+/-2.5% (1.52+/-0.22) along the lesser curvature and 8.3+/-2.1% (0.31+/-0.17) along the greater curvature. These results show that parietal cells of rat gastric mucosa exhibit immunoreactivity to TGF-alpha. Considering the gastroprotective effects of this factor, its non-homogeneous distribution within different areas may be of importance in understanding the lesion pattern of gastric damage after the administration of noxious agents.     

In vitro effects of Clostridium perfringens type D epsilon toxin on water and ion transport in ovine and caprine intestine

Clostridium perfringens type D produces enterotoxaemia in sheep, goats and other animals. The disease is caused by C. perfringens epsilon toxin, and while enterotoxaemia in goats is usually characterized by enterocolitis, the disease in sheep is characterized by systemic lesions (such as lung and brain oedema) with minor and inconsistent changes observed in the intestine. A possible explanation for these differences is that epsilon toxin is more promptly absorbed by sheep than goat intestine. In an attempt to clarify this, we examined the in vitro effects of epsilon toxin on sheep and goat intestine. Pieces of intestinal mucosa from recently slaughtered animals were mounted in a modified Ussing-type chamber where net water flux (J(w)), short-circuit current (I(sc)) and tissue conductance (G(t)) were simultaneously recorded. After 70 min of incubation with epsilon toxin a reduction in absorptive J(w) and an increase in I(sc) and G(t) were observed in colonic tissues of both sheep and goats, but no alterations were registered in the ileum of either species. These in vitro results show that epsilon toxin affects the transport function of the colonic mucosa but it does not seem to produce any transport alteration in the ileum mucosa.     

Combined non-radioactive detection of peptide hormones and their mRNAs in stomach somatostatin cells

Non-radioactive in situ hybridization (ISH) and immunocytochemistry (ICC) have been used to detect somatostatin (SS) messenger RNA (mRNA) and peptide in antropyloric mucosa of the stomach in the rats. We have applied a method of non-radioactive in situ hybridization histochemistry using digoxigenin labelled oligonucleotide probes to detect somatostatin gene expression in the stomach. In prehybridization stage we used proteinase K (PK) in various concentrations (from 1 to 10 micrograms/ml) and periods (from 10 min to 1 h) but we maintained high background. However it was possible to detect the somatostatin mRNAs in the stomach mucosa making use of either background preventing solutions during the prehybridization, or of levamisole (20 microliters/mg) added into the hybridization buffer or of pepsin. Somatostatin mRNA and peptide signals were scattered all through the mucosa especially localized particularly at the base of the pyloric glands. SS peptide shown by ICC and SS mRNA shown by ISH were observed in different cells.     

Activities of glutathione-S-transferase and ethoxycoumarin-O-deethylase in tissues of camels, sheep, goats and rats.

1. The activities of the drug metabolizing enzymes ethoxycoumarin-O-deethylase, glutathione-S-transferase, and protein concentrations were measured in vitro in the liver, kidney and duodenal mucosa of camels, sheep, goats and rats. 2. Enzyme activities were generally higher in the liver than in the kidney and duodenal mucosa in the four species studied. 3. The activities of ethoxycoumarin-O-deethylase and glutathione-S-transferase in liver of male kids were about one third and half of that in adult male goats, respectively. In the kidney and duodenal mucosa of male kids, the activity of glutathione-S-transferase was about 70% and 53% of that in the mature male goat, respectively. In the latter tissues, however, there was no detectable activity of ethoxycoumarin-O-deethylase. 4. In general, goats and sheep had similar activities of the two enzymes which were significantly higher than those found in camels and rats. 5. Some sex-related differences were noted in the activity of the two enzymes studied. Female sheep had significantly higher hepatic glutathione-S-transferase than the male: while the enzyme activity in the kidney and duodenal mucosa of male goats was significantly higher than in females. Male rats had higher hepatic ethoxycoumarin-O-deethylase activity than females.     

The establishment and reversibility of species affinities in domestic sheep and goats

The establishment and reversibility of cross-species attachments were studied in sheep and goats taken from their mothers at birth and reared in same- or cross-species pairs until 12 months of age. Species affinities were determined at eight to nine months of age by time spent proximate to stimulus herds of sheep and goats housed in separate enclosures within a larger pasture. Sheep reared with goats spent significantly more time with the stimulus goats than did controls (sheep reared with sheep). Likewise, goats reared with sheep spent a significantly greater percentage of time with the stimulus sheep than did control goats. At approximately 13 months of age the sheep were segregated from the goats in separate pastures and were retested, as before, for species affinities after 34 to 90 days of exposure to conspecifics. Experimental subjects demonstrated a significant reversal of species preferences. However, the reversal was more complete for subjects housed for 57 to 90 days in same-species groups than for those tested after 34 to 56 days of exposure to conspecifics. It was concluded that species affinities of sheep and goats are basically learned and that relatively long-standing cross-species social attachments can be reversed by approximately 60 to 90 days of same-species cohabitation.     

Reactions of cells of nasal and sinusoidal mucosa of goats and sheep naturally infected by Oestrus ovis Linné 1758 (Diptera: Oestridae)]

OEstrosis is a very common myiasis of sheep and goats in mediterranean and tropical countries. Goats are suitable hosts for OEstrus ovis but the parasitic burden remain lower than in sheep. Cellular responses (mucous and serous mast cells, eosinophis and globules leucocytes) were measured in 30 infected and 30 non infected sheep and in 23 infected and 24 non infected goats. The presence of OEstrus ovis larvae led to an important inflammatory response in sheep and in goats as well. Furthermore, the intensity of the cellular response correlated with the larva burden, specially with globules leucocytes and eosinophils. Nevertheless, huge differences occurred between sheep and goats responses even in similar larval burden range. Infected sheep showed larger counts of mucous mast cells than goats, the differences were smaller in serous mast cells and eosinophils and no difference was detected in globules leucocytes (intraepithelial mast cells) counts between the two hosts species. These results were compared with those obtained in gastro-intestinal strongyles infections.     

Hypergastrinaemia, abomasal bacterial population densities and pH in sheep infected with Ostertagia circumcincta.

Serum gastrin and pepsinogen concentrations, food intake, abomasal pH and abomasal aerotolerant and anaerobic bacterial populations were measured in sheep infected with Ostertagia circumcincta to search for links between hypergastrinaemia, food intake and changes in the abomasal environment. Abomasal pH and serum gastrin and pepsinogen concentrations were elevated in each of five sheep infected via abomasal cannulae with 150000 exsheathed larval stage three, followed 11 days later by 100000 sheathed larvae given intraruminally. Unparasitised abomasa contained aerotolerant bacterial population densities of between 10(3) and 10(6) cells ml(-1) and these did not change significantly following parasitism. In contrast, anaerobic bacterial population densities increased markedly by about 10(4)-fold following parasitism. Anaerobic numbers changed rapidly when abomasal pH increased from 2.5 to 3.5. At pH 4 and above, anaerobic bacterial numbers approached levels expected in rumen contents but parameters other than pH did not relate to bacterial numbers. Brief periods when serum gastrin was lower than expected, coinciding with raised abomasal pH, were not explicable by increased bacterial numbers. Food intake, which decreased for a variable period from around Day 5 p.i., correlated poorly with serum gastrin concentration, suggesting hypergastrinaemia is not the sole cause of anorexia in parasitised animals. The survival of substantial numbers of rumen bacteria in the abomasum at only slightly raised pH may significantly lower the bacterial protein available to the sheep.     

Proteomic analysis of the abomasal mucosal response following infection by the nematode, Haemonchus contortus, in genetically resistant and susceptible sheep

Sheep have a variable ability to resist gastrointestinal nematode infection, but the key factors mediating this response are poorly defined. Here we report the first large-scale application of quantitative proteomic technologies to define proteins that are differentially abundant between sheep selectively bred to have an enhanced (resistant) or reduced (susceptible) ability to eliminate nematodes. Samples were collected from the abomasal mucosa three days after experimental challenge with the nematode, Haemonchus contortus. This timing reflects the initial interaction of host and parasite, and the tissue represents the immediate interface. We identified and quantified more than 4400 unique proteins, of which 158 proteins showed >1.5 fold difference between the resistant and susceptible sheep. Trefoil factor 2, a member of RAS oncogene family (RAP1A) and ring finger protein 126 were amongst the proteins found to be highly abundant in the abomasal surface of resistant sheep, whereas adenosine deaminase and the gastrokine-3 like precursor were found at higher levels in susceptible sheep. Construction of gut proteome interaction networks identified mitochondrial function and energetic partitioning as important components of an effective nematode eliminating response. The differentially abundant proteins may be useful targets for phenotypic tests that aim to identify sheep with an enhanced ability to resist nematode infection.     

Histological and immunohistochemical studies of the endocrine cells of the gastrointestinal mucosa of the toad (Bufo regularis)

Using histological and immunhistochemical techniques, nine endocrine cell types were observed in the mucosa of the gastrointestinal tract of the toad, Bufo regularis, viz. enterochromaffin, somatostatin, glucagon, pancreatic polypeptide (PP), secretin, gastric inhibitory peptide (GIP), gastrin-C-terminal pentapeptide (GTPP), neurotensin and bombesin cells. The enterochromaffin cells were distributed throughout the gastrointestinal tract except the rectum. Somatostatin, glucagon, PP, secretin, GIP and GTPP cells were observed both in the stomach and in the small intestine. Neurotensin cells were seen only in the ileum and bombesin cells only in the pyloric and antral parts of the stomach. Immunostaining of consecutive sections did not reveal more than one polypeptide hormone in any of these cell types. It is concluded from the present results that the toad gastrointestinal mucosa contains endocrine cell types that are more or less homologous to those in the mammal alimentary tract, though some of them exhibit a different topographic distribution.     

Body condition is associated with a shorter breeding season and reduced ovulation rate in subtropical goats

To determine the effect of body condition on the characteristics of the breeding season in female goats from subtropical Mexico, does in either greater- or lesser-body condition (n=20/group) were monitored for the expression of estrous behavior, ovulation and ovulation rate between June and April. The commencement of estrus and ovulation occurred earlier (P<0.05) in does in greater than lesser body condition. The cessation of estrus and ovulation was later (P<0.05) in female goats with greater than those with lesser body condition. Does in greater body condition had more (P<0.001) normal estrous cycles than those in lesser body condition. As consequence, does from the greater body condition group had fewer short (P<0.001) or long (P<0.05) estrous cycles than those of in the lesser body condition group. The ovulation rate was greater (P<0.01) in the greater (1.9+/-0.1) than lesser body condition does (1.6+/-0.1). In conclusion, female goats in lesser body condition have a shorter breeding season, more abnormal estrous cycles, and fewer ovulations than does in greater body condition.     

Histological and immunohistochemical studies of the endocrine cells of the gastrointestinal mucosa of the toad (Bufo regularis)

Summary Using histological and immunhistochemical techniques, nine endocrine cell types were observed in the mucosa of the gastrointestinal tract of the toad,Bufo regularis, viz. enterochromaffin, somatostatin, glucagon, pancreatic polypeptide (PP), secretin, gastric inhibitory peptide (GIP), gastrin-C-terminal pentapeptide (GTPP), neurotensin and bombesin cells. The enterochromaffin cells were distributed throughout the gastrointestinal tract except the rectum. Somatostatin, glucagon, PP, secretin, GIP and GTPP cells were observed both in the ileum and bombesin cells only in the pyloric and antral parts of the stomach. Immunostaining of consecutive sections did not reveal more than one polypeptide hormone in any of these cell types. It is concluded from the present results that the toad gastrointestinal mucosa contains endocrine cell types that are more or less homologous to those in the mammal alimentary tract, though some of them exhibit a different topographic distribution.     

Localization of serotonin, cholecystokinin and somatostatin immunoreactivity in the lower respiratory tract of embryonic, foetal and postnatal sheep.

The lower respiratory tract of the sheep was studied by light-microscopical immunocytochemistry for serotonin, cholecystokinin, somatostatin, bombesin and calcitonin during different periods of lung development; embryonic, foetal and postnatal. At embryonic period only intraepithelial serotonin-containing cells as solitary neuroendocrine cells (NEC) and neuroepithelial bodies (NEB) were found. At foetal stages, immunoreactive cells to serotonin, cholecystokinin and somatostatin were observed in airway epithelium, as solitary NEC and NEBs, and in autonomic intrapulmonary ganglia as single or clusters of small intensely-fluorescent (SIF) cells. In postnatal sheep, serotonin- and cholecystokinin-containing cells were found within airway mucosa as solitary NECs and NEBs. No immunoreactive cells were observed with antiserum to bombesin and calcitonin. Quantitative studies showed that serotonin was the predominant substance, and that solitary neuroendocrine cells were more numerous in distal conducting airways and at foetal stages.     

The distribution of endocrine cells in the mucosa of the gastrointestinal tract of the house musk shrew,Suncus murinus (Insectivora)

Summary The distribution of endocrine cells in the gastrointestinal tract of the house musk shrew, Suncus murinus (Family Soricidae, Order Insectivora) was studied immunohistochemically. The hormones investigated were gastrin, cholecystokinin (CCK), somatostatin, secretin, glucagon, gastric inhibitory polypeptide (GIP), motilin and neurotensin. In the gastric mucosa, gastrin and somatostatin cells were only found in the pyloric regions, and no other hormonal cell-types were observed. In the intestinal mucosa, the largest number of endocrine cells belonged to the gastrin and glucagon/glicentin cell-types, whereas CCK-33/39 and secretin cells were the least numerous. Numbers of other cell-types were intermediate between these two groups. The gastrin and GIP cells were mostly localized in the proximal portion of the intestine, decreasing in number towards the distal portion. The motilin and CCK-33/39 cells were restricted to the proximal half. The glucagon/glicentin and neurotensin cells were most abundant in the middle portion. The somatostatin and secretin cells, although only present in small numbers, were randomly distributed throughout the intestine. This characteristic distribution of gastrointestinal endocrine cells is discussed in comparison with the distribution patterns of other mammals.Dr. Munemitsu Hoshino, who was Professor of the Department of Pathology and directed this study, passed away on May 23rd 1988     

Glycosylated haemoglobin: an indicator of long-term blood glucose in domestic sheep and goats

1. Percentages of glycosylated Hb were determined in (32) Najidi sheep (Ovis ovies) and (20) Nubian goats (Capra hiscas) from Saudi Arabia, using the thiobarbituric acid (TBA) method. 2. The levels of glycosylated Hb in sheep (3.24%) and in goats (3.96%) differ significantly from human controls (4.9%) (P greater than 0.001). 3. Generally, low blood glucose and shorter erythrocyte life span in sheep and relatively in goats are reflected in a lower value for glycosylated Hb, indicating that glycosylated Hb may be used as a valid index of long-term mean blood glucose in sheep and goats.     

Glycoprotein hormone alpha-subunit in human stomach

To demonstrate the immunoreactive alpha-subunit of human chorionic gonadotropin (hCG) or glycoprotein hormones in non-neoplastic gastric mucosa, and to clarify the nature and significance of alpha-subunit-immunoreactive cells, immunohistochemical studies were performed on gastric mucosa using polyclonal antibodies for hCG alpha and beta, hLH beta, hFSH beta, hTSH beta, and gastrin, and a monoclonal antibody for hCG alpha. Surgically resected stomachs were classified as follows: nearly normal (Group A); antral gastritis (Group B); fundic gastritis with pseudopyloric glands (Group C); and intestinal metaplasia (Group D). Cells immunoreactive for the alpha-subunit were present in the pyloric glands and to a lesser extent in the fundic glands (Groups A and B). Almost all alpha-subunit-immunoreactive cells were nonreactive for the beta-subunits of the four glycoprotein hormones. alpha-subunit-immunoreactive cells corresponded to gastrin-containing cells in the pyloric glands, but were unrelated to gastrin in the fundic glands. In fundic gastritis, alpha-subunit-immunoreactive cells appeared to increase (Group C), and many hyperplastic foci were observed in atrophic glands with hyperplasia of the argyrophilic cells (Groups C and D). Isolated hCG alpha or the alpha-subunit of glycoprotein hormones may be present in the endocrine cells of gastric mucosa, and alpha-subunit-immunoreactive cells in the fundic glands seem to proliferate in fundic gastritis.