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1.
The functioning of the gastrointestinal tract is under the control of the most extensive system of peripheral neurons in the body, the enteric nervous system, and the largest endocrine system of the body, the GEP endocrine system. The enteric nervous system in large mammals contains 500 million neurons, and the GEP endocrine system produces more than 30 hormones. Numerous enteric neuropathies affecting both humans and animals have been described and digestive disorders affect commercially important species, such as horses and cattle. The most severe enteric neuropathies (e.g., lethal white syndrome in horses or Hirschsprung's disease in humans) can be fatal. Also, horses with ileus or other digestive disorders are commonly euthanized. In this review we discuss examples of enteric neuropathies that affect agricultural animals and humans: prion disease, postoperative ileus, distal enteric aganglionosis, and infective diarrhea. Enteric neurons and glia are a location of prion proteins and are involved in transmission of the infection from gut to brain and brain to gut. Postoperative ileus is a complex disorder involving the local inhibitory effects of sympathetic nervous system activation and the release of opioids, presumably from enteric neurons. Intestinal inflammation, especially of the external muscle that includes enteric ganglia, also occurs in ileus. Congenital distal bowel aganglionosis, responsible for lethal white syndrome in horses, Hirschsprung's disease in humans, and similar conditions in mice and rats, is a fatal condition if untreated. Mutations of the same genes can cause the condition in each of these species. The only effective current treatment is surgical removal of the aganglionic bowel. Infectious diarrheas involve activation of enteric secretomotor neurons by pathogens and the toxins they produce, which causes substantial fluid loss. Strategies to target enteric neurons in the treatment of secretory diarrheas have not been developed. Disorders of enteroendocrine cells, other than GEP endocrine tumors, are less well documented. However, evidence for the involvement of gut endocrine cells in a subset of patients with irritable bowel syndrome, and in the symptomology of celiac disease, has been demonstrated. Further investigation of the involvement of enteric neural and endocrine signaling systems in digestive disorders, especially in agricultural and companion animals, may lead to diagnostic and therapeutic advances. 相似文献
2.
动物肠道生理活动受到各级神经系统及体液的调控,特别是依赖于肠神经系统的调控作用.肠神经包括肌间神经丛和粘膜下神经丛,其各类神经元可通过多种神经递质的相互作用来调节肠道的分泌和运动.论文就脊椎动物肠道中几种主要的神经递质的分布及功能作一简要论述,以期为进一步探讨肠神经系统调节机制及脊椎动物肠道疾病的研究提供基础性资料. 相似文献
3.
Immunohistochemical examinations of the enteric nervous system (ENS) were performed on biopsies of healthy cats and compared to findings in cats suffering from inflammatory bowel disease or intestinal lymphoma. In lymphocytic–plasmacytic enterocolitis all affected samples had significant reductions in glial fibrillary acidic protein and vasoactive intestinal peptide (VIP) and mostly of neuron-specific enolase (NSE) possibly reflecting alterations in enteric glial cells and neurons. In cases with eosinophilic gastroenterocolitis significantly reduced phosphorylated neurofilament (PN) expression was present suggesting a disturbance in neuronal cytoskeleton, whereas cats with fibrosing enteropathy had reduced expression of NSE, non-phosphorylated neurofilaments (NPN), PN and VIP, possibly reflecting neuronal disturbances. In cases with intestinal lymphoma only the reduction in PN and the increase in NPN were obvious suggesting direct damage or interference of neoplastic cells with enteric neurons. In conclusion, structural and functional alterations of the ENS may contribute to clinically evident signs of vomiting and/or diarrhea. 相似文献
4.
《Research in veterinary science》2012,92(3):e129-e135
Immunohistochemical examinations of the enteric nervous system (ENS) were performed on biopsies of healthy cats and compared to findings in cats suffering from inflammatory bowel disease or intestinal lymphoma. In lymphocytic–plasmacytic enterocolitis all affected samples had significant reductions in glial fibrillary acidic protein and vasoactive intestinal peptide (VIP) and mostly of neuron-specific enolase (NSE) possibly reflecting alterations in enteric glial cells and neurons. In cases with eosinophilic gastroenterocolitis significantly reduced phosphorylated neurofilament (PN) expression was present suggesting a disturbance in neuronal cytoskeleton, whereas cats with fibrosing enteropathy had reduced expression of NSE, non-phosphorylated neurofilaments (NPN), PN and VIP, possibly reflecting neuronal disturbances. In cases with intestinal lymphoma only the reduction in PN and the increase in NPN were obvious suggesting direct damage or interference of neoplastic cells with enteric neurons. In conclusion, structural and functional alterations of the ENS may contribute to clinically evident signs of vomiting and/or diarrhea. 相似文献
5.
5-羟色胺（5-hydroxytryptamine,5-HT）作为一种重要的神经递质和胞间信使,具有多种生物学功能。90%以上的5-HT分布在胃肠系统中,在胃肠系统中发挥重要的生理学功能,许多肠道疾病的发生与肠道中5-HT的表达量变化有关。5-HT影响肠黏膜上皮细胞的增殖和维持,同时升高肠黏膜通透性,间接促进杯状细胞黏液的分泌。其作用机制可能是5-HT刺激传入神经元,激活血管活性肠肽、乙酰胆碱的分泌,间接引起腹泻。作者对5-HT引起腹泻的原因,以及对肠黏膜上皮细胞生物学功能的影响作一综述,以期对腹泻等肠道性疾病诊疗具有一定指导作用。 相似文献
6.
Wood JD 《Journal of animal science》2012,90(4):1213-1223
Neurogastroenterology is a subspecialty encompassing relations of the nervous system to the gastrointestinal tract. The central concept is emergence of whole organ behavior from coordinated activity of the musculature, mucosal epithelium, and blood vasculature. Behavior of each effector is determined by the enteric nervous system (ENS). The ENS is a minibrain positioned close to the effectors it controls. The ENS neurophysiology is in the framework of neurogastroenterology. The digestive tract is recognized as the largest lymphoid organ in the body with a unique complement of mast cells. In its position at the "dirtiest" of interfaces between the body and outside world, the mucosal immune system encounters food antigens, bacteria, parasites, viruses, and toxins. Epithelial barriers are insufficient to exclude fully the antigenic load, thereby allowing chronic challenges to the immune system. Observations in antigen-sensitized animals document direct communication between the mucosal immune system and ENS. Communication is functional and results in adaptive responses to circumstances within the lumen that are threatening to the functional integrity of the whole animal. Communication is paracrine and incorporates specialized sensing functions of mast cells for specific antigens together with the capacity of the ENS for intelligent interpretation of the signals. Immuno-neural integration progresses sequentially, beginning with immune detection, followed by signal transfer to the ENS, followed by neural interpretation and then selection of a neural program with coordinated mucosal secretion and a propulsive motor event that quickly clears the threat from the intestinal lumen. Operation of the defense program evokes symptoms of cramping abdominal pain, fecal urgency, and acute watery diarrhea. Investigative approaches to immuno-ENS interactions merge the disciplines of mucosal immunology and ENS neurophysiology into the realm of neurogastroenterology. 相似文献
7.
Mouse inoculation was used to test for the presence of a toxin in the serum, cerebrospinal fluid, and intestinal contents collected from cases of bovine enteric coccidiosis, with and without neurological signs, and from control calves. Intravenous inoculation of mice with 10 mL/kg of serum from calves showing nervous signs caused effects significantly different from those caused by the inoculation of serum from calves not showing nervous signs and from control calves. The effect was particularly evident in female mice. At this dosage severe neurological signs such as loss of righting reflex, seizures and death occurred only with serum from calves with "nervous coccidiosis". The results suggest that serum from the calves with neurological signs contains a neurotoxin. This toxin appears to be highly labile. It was not present in the cerebrospinal fluid at levels comparable to those in the serum. The significance of this labile neurotoxin with respect to the pathogenesis of the neurological signs associated with bovine enteric coccidiosis is unknown. 相似文献
8.
9.
The gastrointestinal epithelium is in close contact with the various components of the chymus, including nutrients, bacteria and toxins. The epithelial barrier has to decide which components are effectively absorbed and which components are extruded. In the small intestine, a nutrient like glucose is mainly absorbed by the sodium linked glucose cotransporter 1 (SGLT1) and the glucose transporter 2 (GLUT2). The expression and activity of both transport proteins is directly linked to the amount of intraluminal glucose. Besides the direct interaction between glucose and the enterocytes, glucose also stimulates different sensory mechanisms within the intestinal wall. The most important types of cells involved in the sensing of intraluminal contents are enteroendocrine cells and neurones of the enteric nervous system. Regarding glucosensing, a distinct type of enteroendocrine cells, the enterochromaffine (EC) cells are involved. Excitation of EC cells by intraluminal glucose results in the release of serotonin (5‐HT), which modulates epithelial functions and activates enteric secretomotorneurones. Enteric neurones are not only activated by 5‐HT, but also directly by glucose. The activation of different cell types and the subsequent crosstalk between these cells may trigger appropriate absorptive and secretory processes within the intestine. 相似文献
10.
Reis BP Zhang S Tsolis RM Bäumler AJ Adams LG Santos RL 《Veterinary microbiology》2003,97(3-4):269-277
Salmonella enterica serovar Typhimurium is an important cause of enteric infections in farm animals and it is one of the most frequent food borne infections worldwide. Serovar Typhimurium lacking the sopB gene is attenuated for induction of host inflammatory response and fluid accumulation into the intestinal lumen, which correlates with clinical diarrhea. SopB is an inositol phosphate phosphatase, but its exact role in the pathogenesis of salmonellosis is still unclear. We employed the bovine ileal ligated loop model to compare the tissue distribution of a sopB mutant and its wild type parent serovar Typhimurium. Sections of the Peyer's patches were histologically processed and immuno-stained for detection of serovar Typhimurium. In addition, samples were processed for transmission electron microscopy, and the profile of expression of host chemokine and cytokine responses was assessed. Ultrastructurally both strains had the same ability to invade intestinal epithelial cells. No differences were detected in the tissue distribution of the sopB mutant and the wild type organism and both strains elicited the same profile of chemokines and pro-inflammatory cytokines. In conclusion, our results indicate that the attenuation of the sopB mutant is associated with pathogenic mechanisms other than invasion and distribution in host intestinal tissues. 相似文献
11.
Parvovirus-like enteropathy in Missouri turkeys 总被引：1，自引：0，他引：1
A viral enteric disease of young turkeys characterized by stunting of affected birds, diarrhea, and increased mortality is described. Eosinophilic intranuclear inclusion bodies were found in the absorptive epithelial cells of the ileum. Electron microscopy of formalin-fixed tissue revealed that the intestinal inclusions contained numerous loosely packed 15-to 20-nm hexagonal particles. The size, shape, and intranuclear location have been used to tentatively identify these particles as parvoviruses. 相似文献
12.
A descriptive study of the frequency and characteristics of proliferative enteropathy in swine in Ontario by analyzing routine animal health surveillance data 
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下载免费PDF全文 Wilson JB Pauling GE McEwen BJ Smart N Carman PS Dick CP 《The Canadian veterinary journal. La revue veterinaire canadienne》1999,40(10):713-717
Routine surveillance data, collected on pathology submissions at the Animal Health Laboratory in Guelph between 1992 and 1997, were analyzed to determine demographic, clinical, and pathologic characteristics of cases of proliferative enteropathy and the frequency of this condition relative to other infectious enteric diseases in swine in Ontario. The most commonly reported disease was Escherichia coli enteritis (average cases/year = 70.0). Among infectious enteropathies that occur typically in neonatal pigs, coccidiosis (28.4 cases/year) and rotaviral enteritis (5.6 cases/year) were reported. Among infectious enteropathies generally associated with diarrhea in weaner and grower/finisher pigs, the most frequently reported was proliferative enteropathy (27.6 cases/year), followed by swine dysentery (23.3 cases/year), transmissible gastroenteritis (19.6 cases/year), and salmonellosis (8.4 cases/year). Diarrhea and bloody diarrhea were reported in 29% and 31%, respectively, of herds diagnosed with proliferative enteropathy. Important gross intestinal lesions included mucosal hypertrophy (62% of cases), hemorrhage (47%), and mucosal necrosis (34%). Histologic intestinal lesions included epithelial hyperplasia (90% of cases), mucosal necrosis (59%), and inflammation (49%). Our results suggest that proliferative enteropathy is a major infectious enteric disease in grower/finisher pigs in Ontario. 相似文献
13.
Pathogenesis of porcine rotaviral infection in experimentally inoculated gnotobiotic pigs. 总被引：7，自引：0，他引：7
K W Theil E H Bohl R F Cross E M Kohler A G Agnes 《American journal of veterinary research》1978,39(2):213-220
Porcine rotavirus was shown to infect gnotobiotic pigs and induce an acute enteric disease clinically characterized by diarrhea, anorexia, depression, and occasional vomition. Onset of clinical signs correlated closely with the appearance of lesions within the small intestinal mucosa, and recovery from infection was associated with the regeneration of normal, functional villous epithelium. Villous atrophy, especially in the caudal two-thirds of the small intestine, was the consistent lesion observed in pigs with clinical signs of rotaviral infection. Villi were often short, blunt, and covered with cuboidal epithelial cells. Immunofluorescent microscopy methods demonstrated that the principal site of rotaviral replication was the villous columnar epithelial cells in the small intestine. 相似文献
14.
Koenig J Cote N 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(6):551-559
Colic is a common problem encountered in equine practice. Alteration of gastrointestinal motility is often the underlying cause for abdominal pain. Gastrointestinal motility can be measured as myoelectric activity, mechanical activity, and transit of intraluminal contents. Regulation of motility is based on a complex interaction between central innervation, autonomic innervation, and the enteric nervous system. Various humoral and neurochemical substances are required to interact flawlessly to allow propulsive motility. Ileus is defined as the absence of propulsive aboral movement of gastrointestinal contents, irrespective of its pathophysiology. Potential etiologies for ileus are described in this review. The prokinetic drugs available for clinical use are discussed. Choosing the appropriate prokinetic drug requires knowledge about the complex nature of gastrointestinal motility and its abnormalities. 相似文献
15.
German AJ Hall EJ Day MJ 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(1):14-25
The mucosal immune system may play a critical role in the pathogenesis of small intestinal enteropathies. The aim of the current study was to assess mucosal immune cell populations in dogs with inflammatory bowel disease (IBD), idiopathic antibiotic-responsive diarrhea (ARD), and adverse reactions to food (FR). Endoscopic biopsies were performed of the duodenum of dogs with these conditions and from a group of dogs without enteric disease. Additional control samples were collected after death from other dogs that did not have evidence of enteric disease. Immunohistochemistry and computer-aided morphometry were used to assess the distribution of immune cell subsets in both lamina propria and intestinal epithelium. Compared with controls, dogs with ARD had increased numbers of lamina propria immunoglobulin (Ig) A- plasma cells and CD4+ cells. More marked alterations were noted in dogs with IBD, with significant increases in lamina propria IgG+ plasma cells, T cells (CD3+), CD4+ cells, macrophages, and neutrophils, but with reduced mast cell numbers. Increased intraepithelial CD3+ T cells were also present in the dogs with IBD, compared with controls. However, lamina propria and epithelial populations were unaltered in dogs with FR when compared with controls. The altered mucosal immune cell populations observed in dogs with ARD or IBD may reflect an underlying immunologic pathogenesis in these disorders. 相似文献
16.
Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea. 相似文献
17.
Alfieri Amauri Alcindo Ribeiro Juliane de Carvalho Balbo Luciana Lorenzetti Elis Alfieri Alice Fernandes 《Tropical animal health and production》2018,50(8):1937-1940
Dairy calf rearing unit is a management system that is only recently being implemented by some milk producer’s cooperatives in southern Brazil. However, aspects related to the health profile of the heifer calves that arrive in the rearing unit as well as about biosecurity practices and microbiological challenges have not yet been evaluated in this rearing system in a tropical country. Diarrhea is the main and most frequent consequence of enteric infections in newborn calves. This study, through some etiological and epidemiological characteristics of an outbreak of neonatal diarrhea, has the aim to alert to the possibility of pathogenic microorganism spread in a dairy heifer calf rearing unit. The diarrhea outbreak presented some non-regular characteristics observed in bovine coronavirus (BCoV) enteric infections in dairy calves. The spread of infection was extremely rapid (1 week); the attack rate (>?50%) was much higher than that observed in calves subjected to conventional rearing; and the age range (5 to 90 days) of the affected heifer calves was much broader than that often observed in the BCoV diarrhea worldwide. These unusual epidemiological characteristics observed in this BCoV diarrhea outbreak raise awareness of the health threat present in calf rearing units as well as of the easy and rapid viral spread in a population of young animals from different dairy herds and, therefore, with very distinct immunological status.
相似文献18.
Arno Wünschmann Rodney Frank Kem Pomeroy Sanjay Kapil 《Journal of veterinary diagnostic investigation》2002,14(5):441-444
A case of an enteric coronavirus infection in a 6-week-old dromedary calf is described. The animal had diarrhea for 5 days and died despite symptomatic treatment. Numerous viral particles, approximately 140 nm in diameter, with club-like projections were detected in the feces by electron microscopy. These characteristics were consistent with a coronavirus. Immunohistochemical reactivity with 2 antigenic group II coronavirus-specific antibodies confirmed the presence of viral antigen in colonic epithelial cells. The death of the animal was attributed to a neutrophilic and emphysematous colitis that likely was caused by an infection with a Clostridium sp. 相似文献
19.
Pathogenesis of porcine enteric calicivirus-like virus in four-day-old gnotobiotic pigs 总被引：4，自引：0，他引：4
Eighteen 4-day-old gnotobiotic pigs were orally inoculated with porcine enteric calicivirus-like virus (C strain). Seven additional gnotobiotic pigs served as noninoculated controls. Mild diarrhea developed in all inoculated pigs by postinoculation day (PID) 3 and persisted for 3 to 7 days. Severe diarrhea developed in 2 inoculated pigs between PID 4 and 5. Twelve inoculated and 7 control pigs were euthanatized over a 7-day period. Small intestinal mucosal smears were stained with a fluorescein-conjugated anti-porcine enteric calicivirus-like virus serum. Immunofluorescence was observed in villous epithelial cells (primarily in the duodenum or jejunum) of all inoculated pigs, except for 1 pig euthanatized at PID 7. Villus length was determined in histologic sections of the small intestinal specimens from control and inoculated pigs. Statistically significant (P less than 0.01) villus atrophy was found in the duodenum and/or jejunum of inoculated pigs at PID 3 to 7. These observations were confirmed by scanning electron microscopy, which revealed shortening, blunting, fusion, or absence of villi in the duodenum and jejunum of inoculated pigs at PID 3 to 7. Lesions were not seen in control pigs. Calicivirus-like particles were detected by immune electron microscopy in the large intestinal contents and feces of inoculated pigs from PID 1 to 7. 相似文献
20.
Neurohistological and immunohistochemical examinations of the feline enteric nervous system (ENS) were performed by using antibodies against neuron-specific enolase (NSE), phosphorylated neurofilaments (PN), non-phosphorylated neurofilaments (NPN) and vasoactive intestinal peptide (VIP), whereas glial cells were investigated by using antibodies against glial fibrillary acidic protein (GFAP). The study included full-thickness biopsies of the stomach, duodenum, jejunum, ileum and colon of 11 healthy cats. In this study, immunohistochemical staining of feline ENS with antibodies to NSE, PN and NPN revealed the presence of different ganglionated and aganglionated plexus. The two ganglionated plexus were arranged in a plexus submucosus internus & externus and a plexus myentericus. Furthermore, plexus mucosus and subserosal plexus represented two aganglionated plexus. GFAP-stained cellular elements were smaller than and in close contact to enteric neurons possibly resembling astrocytes of the central nervous system. VIP is one of the major neurotransmitters of enteric inhibitory neurons, and immunoreactivity was present in all layers of the gut, especially in ganglionated plexus. This is the first report, describing feline ENS by using immunohistochemical methods. 相似文献