消化道不同部位灌注大豆寡糖对绵羊几个免疫指标影响

为研究不同剂量大豆寡糖(SBOS)对绵羊体液免疫和细胞免疫功能的影响。试验选用9只安装有永久性瘤胃瘘管、十二指肠瘘管和回肠瘘管的内蒙古半细毛羊羯羊,随机分为3组。试验1组灌注占试验日粮风干物质0.6%的SBOS;试验2组灌注占试验日粮风干物质1.2%的SBOS;对照组不灌注SBOS。试验分3期,分别在瘤胃、十二指肠和回肠3个部位灌注SBOS(每期进行1个部位的灌注)。结果表明:(1)通过瘤胃和十二指肠灌注,SBOS提高了绵羊外周血CD4细胞数量、CD4/CD8值、血清IgG和IgA含量,其中以1.2%组效果最为明显;(2)回肠灌注SBOS,增加了外周血CD8细胞数量,降低了CD4/CD8值;0.6%组增加了CD4细胞数量,提高了IgG、IgA含量;1.2%组降低了CD4细胞数量,在第14天和21天达到了显著水平(P<0.05),并且在14 d和21 d降低了IgG、IgA含量。因此,SBOS可以在一定程度上提高绵羊的免疫功能。     

An immunohistochemical study of the gastrointestinal endocrine cells in the C57BL/6 mice

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) of the gastrointestinal tract of C57BL/6 mouse was studied with immunohistochemical method using seven types of specific anti-sera against chromogranin A (CGA), serotonin, somatostatin, human pancreatic polypeptide (HPP), glucagon, gastrin and cholecystokinin (CCK)-8. In this study, all these seven types of immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle in shape (open-type cell) while cells showing round in shape (closed-type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of gastrointestinal tract. CGA-IR cells were demonstrated throughout the whole gastrointestinal tract and they showed most predominant in the pylorus and duodenum. Serotonin-IR cells were detected throughout whole gastrointestinal tract and they showed highest frequency in the stomach and colon. Somatostatin-IR cells were demonstrated throughout whole gastrointestinal tract except for large intestine and showed highest frequency in the fundus. HPP-IR cells were found in the fundus with rare frequency. Peculiarly, glucagon-IR cells were restricted to the fundus, ileum and colon with a few frequencies. Gastrin-IR cells were restricted to the pylorus with numerous frequency and CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with numerous and/or a few frequencies, respectively. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in C57BL/6 mouse.     

The regional distribution and relative frequency of gastrointestinal endocrine cells in SHK-1 hairless mice: an immunohistochemical study

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, caecum, colon and rectum) of the gastrointestinal tract of SKH-1 hairless mice were investigated using immunohistochemical methods and seven types of specific antisera against somatostatin, serotonin, glucagon, cholecystokinin (CCK)-8, secretin, pancreatic polypeptide (PP) and gastrin. In this study, somatostatin-, serotonin-, glucagon-, CCK-8-, secretin- and gastrin-immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle-shaped (open-type cell) while cells that were round in shape (close-type cell) were occasionally found in the stomach regions. Their relative frequencies were varied according to each portion of gastrointestinal tract. Somatostatin-IR cells were found throughout the gastrointestinal tract except for the large intestine. Serotonin-IR cells were detected throughout the whole gastrointestinal tract and were the most predominant endocrine cell types in this species of mouse. Glucagon-IR cells were restricted to the fundus, occurring rarely. CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with frequencies that were numerous, moderate and few, respectively. Peculiarly, secretin-IR cells were demonstrated in the whole intestinal tract with either few or rare frequencies. Gastrin-IR cells were restricted to the pylorus and were numerous. However, no PP-IR cells were found in this study. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in SKH-1 hairless mouse.     

Effects of cholecystokinin-receptor antagonists on Fos-like immunoreactivity stimulated by sulfated cholecystokinin-8 in neurons of the myenteric plexus and hindbrain of rats

OBJECTIVE: To evaluate the role of cholecystokinin (CCK)-receptor antagonists in the activation of enteric and hindbrain neurons by sulfated CCK-8. ANIMALS: 81 male Sprague-Dawley rats. PROCEDURE: Rats were allocated to 10 groups (5 to 22 rats/group). Each rat received 2 IP injections (15 minutes between injections). The first injection consisted of a specific CCK2-receptor (CCK2R) antagonist (L365,260; 150, 500, or 1,000 microg/kg), a specific CCK1-receptor (CCK1R) antagonist (devazepide; 150 microg/kg), or 1% dimethyl sulfoxide (DMSO [ie, vehicle]), and the second injection consisted of sulfated CCK-8 (10 microg/kg) or saline (0.9% NaCl) solution. Rats were anesthetized and perfused with 500 mL of Krebs saline solution, and the myenteric plexuses of the duodenum and jejunum were collected. Rats were then perfused with 500 mL of phosphate-buffered 4% formaldehyde solution; rats were then euthanatized, and the hindbrain of each was harvested. Tissues were stained by use of a diaminobenzidine reaction enhanced with nickel to reveal Fos-like immunoreactivity (Fos-LI), a marker of neuronal activation, in the aforementioned neurons. RESULTS: Sulfated CCK-8 significantly increased Fos-LI in the myenteric and hindbrain neurons, compared with values for the DMSO injections. All dosages of L365,260 failed to attenuate this increase; however, injection of devazepide attenuated the increase in Fos-LI. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of the results of this study reveals that sulfated CCK-8 activates myenteric and hindbrain neurons of rats primarily through CCK1 R. It provides evidence that CCK2R are lacking or not functional in the gastrointestinal tract of rats.     

CCK1 central receptor antagonist prevented the intestinal stress symptoms in sheep

The aim of this study was to determine the influence of mechanically induced duodenal distension (DD) and lorglumide (CCK1 receptor antagonist) premedication on electrical activity of various parts of gastrointestinal (GI) tract and the blood plasma cortisol level in sheep. The influence of lorglumide on the unfavourable effects of duodenal distension (performed with a balloon filled with water--40 and 80 ml; DD40 and DD80) was investigated in this study. These effects in sheep were as follows: the atony of forestomachs and abomasum and the transitory stimulation of myoelectrical activity of small intestine and distal parts of large intestine. The animals, under general anaesthesia, had electrodes inserted into the muscular layers of the organ, the duodenal fistula and (in another group of animals) also the ruminal fistula. Five minute duodenal distension (DD40 and DD80) caused an immediate and complete inhibition of the frequency of spike bursts as well as reticulo-ruminal and abomasal contractions, but also a transitory significant increase of spike bursts of the intestinal wall. The duodenal distension (DD40 and DD80) caused a significant increase of plasma cortisol concentration. Lorglumide did not significantly change the motility of gastrointestinal tract and cortisol concentration, but 10 min after the intracerebroventricular (i.c.v.) infusion in the doses of 1 and 2 mg in toto (i.e. 25 and 50 micrograms/kg B.W.) it decreased the cortisol concentration by 59.7%, as compared with the control values. Lorglumide administered in the above mentioned doses 10 min before the DD40 prevented all signs of intestinal stress and decreased the release of cortisol, but only for 10 min since the beginning of the duodenal distension. It is concluded, that lorglumide--an antagonist of the central CCK1 receptors can be an effective antistressoric agent in the stomach atony caused by the duodenal distension (mechanical-algetic-emotional stress) in sheep.     

Endotoxin absorption in hay-fed and lactic acidotic sheep.

Absorption of endotoxin from the gastrointestinal tract was evaluated in hay-fed and lactic acidotic sheep duodenally infused with 10 mg of Escherichia coli endotoxin, and in lactic acidotic sheep not infused. The effect of abomasal fluid on biological activity of endotoxin was also evaluated. Leukopenia was the criterion used for detecting endotoxemia. Absorption of endotoxin from the gastrointestinal tract was not detected in either hay-fed or lactic acidotic sheep. Endotoxin appeared to maintain its activity after incubation with abomasal fluid, and the presence of endogenous endotoxin in abomasal contents was indicated. The results indicate that endotoxin of alimentary origin may not be involved in the lactic acidosis syndrome in ruminants.     

The regional distribution and relative frequency of gastrointestinal endocrine cells in the nude mice, Balb/c-nu/nu: an immunohistochemical study

The distributions and frequencies of some endocrine cells in the eight portions of the gastrointestinal (GI) tract - fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum of the nude mouse, Balb/c-nu/nu were studied with immunohistochemical method using six types of anti-sera against serotonin, gastrin, cholecystokinin (CCK)-8, somatostatin, glucagon and human pancreatic polypeptide (hPP). All of six types of immunoreactive (IR) cells were identified. Most of IR cells in the intestinal portion were generally spherical or spindle in shape (open type cell) while cells showing round in shape (close type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of GI tract. Serotonin-IR cells were detected throughout the whole GI tract and they showed the highest frequency in the pylorus. Gastrin-IR cells were restricted to the pylorus and duodenum with numerous and a few frequencies, respectively. CCK-8-IR cells were also restricted to the pylorus, duodenum and jejunum with numerous, a few and rare frequencies, respectively. Somatostatin-IR cells were demonstrated throughout the whole GI tract except for the colon and rectum, and they showed the highest frequency in the fundus. In addition, glucagon- and hPP-IR cells were restricted to the fundus and rectum, respectively with a few frequencies. In conclusion, the general distribution patterns and relative frequency of GI endocrine cells of the nude mouse, Balb/c-nu/nu was similar to that of other strains of mice. However, some strain and/or species-dependent unique distributions and frequencies of endocrine cells were also observed especially for somatostatin- and hPP-IR cells.     

Reference Values and Repeatability of Transabdominal Ultrasonographic Gastrointestinal Tract Thickness and Motility in Healthy Donkeys (Equus asinus)

The present study aimed to provide reference ranges for the wall thickness and motility pattern of the gastrointestinal tract from a sample of donkeys (Equus asinus) population using B-mode ultrasonography. In the present study, 30 clinically healthy donkeys (Equus asinus) (15 males and 15 females), aged 2–20 year old and weighed 100–280 kg were randomly selected for B-mode ultrasonographic scanning of the abdomen. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was assessed. Moreover, the motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was evaluated over a period of 3 minutes. Abdominal ultrasonographic scanning of the gastrointestinal tract of healthy donkeys explored that the stomach, duodenum, jejunum, left colon, right colon, and cecum could be visualized easily. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was 7.0 ± 0.9 mm, 3.3 ± 1.0 mm, 5.4 ± 0.6 mm, 5.1 ± 0.5 mm, 5.4 ± 0.5 mm, and 5.4 ± 0.6 mm, respectively. The thickest part of the gastrointestinal tract is the stomach, whereas the thinnest part is the duodenum. The motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was 7.7 ± 1.3 contractions/3 minutes, 6.9 ± 1.1 contractions/3 minutes, 4.1 ± 1.2 contractions/3 minutes, 5.5 ± 1.3 contractions/3 minutes, and 4.0 ± 0.8 contractions/3 minutes, respectively. Both the duodenum and jejunum contractions were significantly higher than that of the left colon, right colon, and cecum. This is the first study reporting the reference values for both the wall thickness and motility pattern of the gastrointestinal tract in healthy donkeys (Equus asinus) in Egypt. Good knowledge of these standard and reference values of the wall thickness and motility pattern of gastrointestinal tract structures represents a step in the early diagnosis of the gastrointestinal disorders, including colic in such animal species.     

Binding of radiolabeled porcine motilin and erythromycin lactobionate to smooth muscle membranes in various segments of the equine gastrointestinal tract

OBJECTIVE: To identify and characterize motilin receptors in equine duodenum, jejunum, cecum, and large colon and to determine whether erythromycin lactobionate competes with porcine motilin for binding to these receptors. SAMPLE POPULATION: Specimens of various segments of the intestinal tracts of 4 adult horses euthanatized for reasons unrelated to gastrointestinal tract disease. PROCEDURE: Cellular membranes were prepared from smooth muscle tissues of the duodenum, jejunum, pelvic flexure, and cecum. Affinity and distribution of motilin binding on membrane preparations were determined by use of 125I-labeled synthetic porcine motilin. Displacement studies were used to investigate competition between 125I-labeled synthetic porcine motilin and erythromycin lactobionate for binding to motilin receptors in various segments of bowel. RESULTS: Affinity of 125I-labeled synthetic porcine motilin for the equine motilin receptor was estimated to be 6.1nM. A significantly higher number of motilin receptors was found in the duodenum than in the pelvic flexure and cecum. The jejunum had a significantly higher number of motilin receptors than the cecum. Erythromycin lactobionate displacement of 125I-labeled porcine motilin from the equine motilin receptor did not differ significantly among various segments of bowel. CONCLUSIONS AND CLINICAL RELEVANCE: Motilin receptors were found in the duodenum, jejunum, pelvic flexure, and cecum of horses. The highest number of motilin receptors was in the duodenum, and it decreased in more distal segments of bowel. Erythromycin lactobionate competed with motilin binding in the equine gastrointestinal tract. This suggests that 1 of the prokinetic actions of erythromycin in horses is likely to be secondary to binding on motilin receptors.     

Distribution of 5-hydroxytryptamine,Ghrelin or Glucagon-like Peptide-1 Immunopositive Cells in the Gastrointestinal Tract of Meihua Pig

In order to analyze the distributions and densities of endocrine cells in the gastrointestinal tract of Meihua pig (an elite native breed of Guangdong province, China), 6 healthy piglets weaned at 30 days of age were fed with the same diet till 65 days of age. At 65 days of age, different sections of the gastrointestinal tract of each piglet were collected, and the features and densities of 5-hydroxytryptamine (5-HT), ghrelin and glucagon-like peptide-1 (GLP-1) immunopositive cells were detected by immunohistochemistry. The results showed that the 5-HT positive cells distributed at the epithelial layer throughout the intestinal tract (duodenum, jejunum, ileum and colon) with a variety of features (e.g. cone, round, spindle), and they could be classified into either open-shape or closed-shape type, the density of 5-HT positive cells in duodenum was highest; The ghrelin positive cells were located along the gastrointestinal tract (gastric glands, pylorus, duodenum and jejunum) with both open-shape and closed shape, and its density decreased along the tract with most cells in gastric glands; The GLP-1 positive cells were observed along the intestinal tract, but its density increased from duodenum to ileum and then decreased in colon. This study might provide supporting data for further study of the gastrointestinal physiology of Meihua pig.     

梅花猪胃肠道5-羟色胺、胃饥饿素和胰高血糖素样肽-1免疫阳性细胞分布特征研究

为了解中国优良地方猪种梅花猪胃肠道内分泌细胞的分布与形态特征,本试验选取6头30日龄断奶健康梅花仔猪,在相同条件下饲养至65日龄,所有仔猪饲喂相同日粮,自由采食饮水。试验结束时,收集仔猪胃肠道各段组织样品,应用免疫组织化学方法观察3种胃肠道内分泌激素5-羟色胺（5-HT）、胃饥饿素（ghrelin）和胰高血糖素样肽-1（GLP-1）免疫阳性细胞的分布及形态特征,并对阳性细胞密度进行分析。结果显示,梅花猪的肠道不同部位（十二指肠、空肠、回肠和结肠）均存在5-HT阳性细胞,主要位于肠上皮组织中,呈锥形、圆形、梭形等形态,可分为开放型和闭合型,其中十二指阳性细胞肠密度显著高于其他肠段（P<0.05）;梅花猪的胃肠道不同部位均有Ghrelin阳性细胞,阳性细胞密度也是随胃肠道走向递减,胃腺体部密度最高;梅花猪的肠道不同部位均有GLP-1阳性细胞,阳性细胞密度沿肠道走向呈抛物线分布,其中回肠数量最多。本试验结果为进一步探究梅花猪胃肠道生理奠定了基础。     

Distribution of muscarinic receptor subtypes and interstitial cells of Cajal in the gastrointestinal tract of healthy dairy cows

OBJECTIVE: To describe the distribution of muscarinic receptor subtypes M(1) to M(5) and interstitial cells of Cajal (ICCs) in the gastrointestinal tract of healthy dairy cows. SAMPLE POPULATION: Full-thickness samples were collected from the fundus, corpus, and pyloric part of the abomasum and from the duodenum, ileum, cecum, proximal loop of the ascending colon, and both external loops of the spiral colon of 5 healthy dairy cows after slaughter. PROCEDURES: Samples were fixed in paraformaldehyde and embedded in paraffin. Muscarinic receptor subtypes and ICCs were identified by immunohistochemical analysis. RESULTS: Staining for M(1) receptors was found in the submucosal plexus and myenteric plexus. Antibodies against M(2) receptors stained nuclei of smooth muscle cells only. Evidence of M(3) receptors was found in the lamina propria, in intramuscular neuronal terminals, on intermuscular nerve fibers, and on myocytes of microvessels. There was no staining for M(4) receptors. Staining for M(5) receptors was evident in the myocytes of microvessels and in smooth muscle cells. The ICCs were detected in the myenteric plexus and within smooth muscle layers. Distribution among locations of the bovine gastrointestinal tract did not differ for muscarinic receptor subtypes or ICCs. CONCLUSIONS AND CLINICAL RELEVANCE: The broad distribution of M(1), M(3), M(5), and ICCs in the bovine gastrointestinal tract indicated that these components are likely to play an important role in the regulation of gastrointestinal tract motility in healthy dairy cows. Muscarinic receptors and ICCs may be implicated in the pathogenesis of motility disorders, such as abomasal displacement and cecal dilatation-dislocation.     

Copper,iron, zinc and tannin concentrations throughout the digestive tract of tropical goats and sheep fed a high-fibre tannin-rich diet

The dry season in tropical regions urges livestock to feed on nutritionally very poor diets. It has not been explored how tropical sheep—assumed grazers—and tropical goats—intermediate browsers—cope with a high-fibre tannin-rich diet. This study was designed to determine the effects of a high-fibre and tannin-rich diet on the flow of important microminerals iron (Fe), zinc (Zn) and copper (Cu) throughout the digestive tract of tropical sheep and goats. The feeding trial was set up with twelve adult male animals, six sheep with mean body weight (BW) of 30.3 ± 1.6 kg and six goats with mean BW of 26.4 ± 2.2 kg. The feed consisted of 36% leaves of Millettia ferruginea, 61% hay and 3% concentrate and was offered at 3% of BW (all on dry matter (DM) basis). The total faecal collection was carried out for 7 consecutive days. At the end of the experimental period, the animals were slaughtered to collect liver and digesta samples from the gastrointestinal tract. Feed, digesta and faecal samples underwent analysis of Fe, Zn, and Cu and total tannins (TT). Goats had significantly higher reticulum Cu concentrations expressed on DM as compared to sheep. Faecal Cu concentrations were higher for goats compared to sheep. Reticulum and colon digesta Zn levels were higher in goats than sheep. Abomasum and colon Fe levels were higher in sheep than goats when expressed on DM. These results suggest differences in feed intake, micromineral absorption, secretion and excretion between sheep and goats, pointing to a divergent mineral metabolism as an adaptation to the challenge of a dry season diet having very low nutritive value.     

Influence of indomethacin on endotoxin-induced changes in gastrointestinal myoelectrical activity and some haematological and clinical parameters in the conscious piglet

The effect of indomethacin, administered intravenously at 5 mg/kg, on the changes in gastrointestinal myoelectrical activity, rectal body temperature, clinical appearance and some haematological parameters induced by intravenous bolus injection of endotoxin, at 10 µg/kg, was examined in conscious piglets with electrodes implanted in the antrum pylori, duodenum, jejunum and ileum. Indomethacin inhibited the endotoxin-induced febrile response and the accompanying clinical signs. However, it was without influence on the induced leukopenia and shift to the left. Indomethacin both delayed the onset of and shortened the endotoxin-induced increase in the duration of the antral inhibitory phase and the duodenal phase I activity. It therefore appears that prostanoids are probably not the main factors involved in the endotoxin-induced haematological and gastrointestinal myoelectrical activity changes in the piglet.     

Study on the Effects of Increasing Production Rate of Ruminal Acetate and Butyrate on Their Absorption and Passage in Alimentary Tract of Sheep

Six Inner Mongolian semifine-wool wethers（1.5 years old,29-31 kg BW） fitted with a ruminal and a duodenum cannula were used to study the effects of increasing production rate of ruminal acetate and butyrate on their absorption and passage in alimentary tract by simulating continuous feeding and pulse-continuous infusion technology.The sheep were     

ULTRASONOGRAPHIC FINDINGS IN CHOLECYSTOKININ-INDUCED PANCREATITIS IN DOGS

Pancreatitis can be induced in dogs by intravenous infusion of supraphysiologic doses of synthetic cholecystokinin octapeptide (CCK-8). Eight anesthetized female beagles were given either CCK-8 or saline in a randomized, blinded fashion and had abdominal ultrasonography to study the development of pancreatic lesions. Pancreatic lesions were apparent 2 hours after the start of CCK-8 infusion and included swelling, interlobular and subcapsular fluid accumulation and patchy hypoechogenicity of the gland parenchyma. CCK-8 had a variable effect on gallbladder emptying. No signs of biliary obstruction or duodenal lesions were identified. Dogs given CCK-8 had severe edematous pancreatitis at necropsy six hours after the start of the infusion. Compared to the oleic acid model of pancreatitis, CCK-8 infusion induces a rapid onset of pancreatitis and an ultrasonographic appearance that reflects diffuse edema of the gland. The short time-scale of the experiment may account for the relative absence of secondary lesions affecting the biliary tract or duodenum compared to the naturally-occurring disease.     

Enterovirus Neutralizing Activity in the Gastrointestinal Tract of Piglets

Neutralizing activity against porcine enterovirus strain T80 was demonstrated in the contents of the stomach, duodenum or ileum of four piglets which were suckling dams whose milk contained neutralizing substances against the same virus. No neutralizing activity was detected in the gastrointestinal contents of an unsuckled piglet or in four weaned piglets. Extracts of intestinal tissue from each of the above piglets failed to neutralize the virus. Four weaned piglets were dosed orally with live T80 virus. From nine days after infection virus neutralizing activity was found in extracts of tissue prepared from the duodenum, jejunum, ileum, caecum and colon but not in the contents of the gastrointestinal tract and a serological response to the virus was demonstrated. No virus neutralizing activity was detected in gastrointestinal tissue or contents from four weaned piglets inoculated parenterally with live T80 virus or in four piglets dosed orally with inactivated T80 virus and these piglets did not respond serologically to the virus.     

Long-term feed intake regulation in sheep is mediated by opioid receptors

These experiments were conducted to determine if 1) syndyphalin-33 (SD33), a mu-opioid receptor ligand, affects feed intake; 2) SD33 effects on feed intake are mediated by actions on opioid receptors; and 3) its activity can counteract the reduction in feed intake associated with administration of bacterial endotoxin. In Exp. 1, 5 mixed-breed, castrate male sheep were housed indoors in individual pens. Animals had ad libitum access to water and concentrate feed. Saline (SAL; 0.9% NaCl) or SD33 (0.05 or 0.1 micromol/kg of BW) was injected i.v., and feed intake was determined at 2, 4, 6, 8, 24, and 48 h after the i.v. injections. Both doses of SD33 increased (at least P < 0.01) feed intake at 48 h relative to saline. In Exp. 2, SAL + SAL, SAL + SD33 (0.1 micromol/kg of BW), naloxone (NAL; 1 mg/kg of BW) + SAL, and NAL + SD33 were injected i.v. Food intake was determined as in Exp. 1. The SAL + SD33 treatment increased (P = 0.022) feed intake at 48 h relative to SAL + SAL. The NAL + SAL treatment reduced (at least P < 0.01) feed intake at 4, 6, 8, 24, and 48 h, whereas the combination of NAL and SD33 did not reduce feed intake at 24 (P = 0.969) or 48 h (P = 0.076) relative to the saline-treated sheep. In Exp. 3, sheep received 1 of 4 treatments: SAL + SAL, SAL + 0.1 micromol of SD33/kg of BW, 0.1 microg of lipopolysaccharide (LPS)/kg of BW + SAL, or LPS + SD33, and feed intake was monitored as in Exp. 1. Lipopolysaccharide suppressed cumulative feed intake for 48 h (P < 0.01) relative to saline control, but SD33 failed to reverse the reduction in feed intake during this period. These data indicate that SD33 increases feed intake in sheep after i.v. injection, and its effects are mediated via opioid receptors. However, the LPS-induced suppression in feed intake cannot be overcome by the opioid receptor ligand, SD33.     

Histamine Receptor Expression in the Gastrointestinal Tract of Dogs

Histamine is an important mediator of many physiological processes including gastrointestinal function that acts via four different histamine receptors (H1R to H4R). Elevated histamine levels and increased HR messenger ribonucleic acid (mRNA) have been shown in humans with gastrointestinal disorders such as irritable bowel syndrome or allergic intestinal diseases. As there is limited knowledge concerning the distribution of histamine receptors (HR) in dogs, one aim of this study was to investigate the expression of histamine 1 receptor (H1R), histamine 2 receptor (H2R) and histamine 4 receptor (H4R) in the canine gastrointestinal tract at protein level using immunohistochemistry. Histamine 1 receptor, H2R and H4R were widely expressed throughout the canine gastrointestinal tract including epithelial, mesenchymal, neuronal and immune cells. In addition, in situ hybridisation was established for detecting canine H4R mRNA. Results showed H4R mRNA to be present in enterocytes, lamina propria immune cells and submucosal plexus in the duodenum and colon of nearly all investigated animals. The results elucidate the importance of HR in the canine gut and represent the basis for investigating their possible impact on canine inflammatory gastrointestinal disorders.     

Effect of adrenalectomy on cholecystokinin-8-induced Fos-like immunoreactivity in myenteric neurons and the dorsal vagal complex in rats

OBJECTIVE: To investigate the effect of adrenalectomy on cholecystokinin-8 (CCK-8)-induced Fos-like immunoreactivity (Fos-LI) in the myenteric neurons of the dorsal vagal complex (DVC) in rats. ANIMALS: 16 male Sprague Dawley rats. PROCEDURES: Rats were allocated to 1 of 2 groups and underwent adrenalectomy or a sham adrenalectomy procedure. Rats were challenged with a supraphysiologic dose of CCK-8 (40 microg/kg) or physiologic saline (0.9% NaCl) solution (0.5 mL) administered IP; after 90 minutes, rats were euthanized, and Fos-LI was quantified in the DVC (at the levels of the area postrema, nucleus tractus solitarii, and dorsal motor nucleus of the vagus) and the myenteric neurons of the duodenum and jejunum by use of a diaminobenzidine reaction enhanced with nickel. The Fos-LI-positive cells were counted by use of an automated system and manually in the DVC and intestinal samples, respectively. Counts of Fos-LI in the different hindbrain levels and myenteric neurons were compared between the adrenalectomy--and shamtreated groups and between the CCK-8- and saline solution-treated groups. RESULTS: After adrenalectomy, CCK-8-induced Fos-LI was attenuated only in the myenteric neurons of the duodenum. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that the adrenal gland has a role in the activation of myenteric neurons by CCK-8 in rats.