Study On The The Adaptability Of Gansu Zokor (Myospalax Cansus)'s Digestive Tract

Gansu zokor (Myospalax cansus) is a solitary fossorial rodent inhabitingin its own tunnel system all its life. We studied the morphological, histological and theNOS neurons in the myenteric plexus of the digestive tract in order to clarify theadaptability of Gansu zokor's digestive tract in morphylogy, histology and physiology.Results as follow:Firstly, we observed the various morphological characteristic of Gansu zokor'sgastrointestinal tract in four seasons with morphological methods. The results were thatthe morphological characteristics of Gansu zokor's digestive tract in different seasonswere variation. Wet and dry matters of Gansu zokor's digestive tract were significantvariation, and were highest in spring. In different seasons, the morphlogicalcharacteristics of Gansu zokor's gastrointestinal tract were variation, which maybeadaptive to its feeding habit, food quality and energy requirement and that ought to bethe one of digestive measures. Animals that utilise low quality foods or require moreenergy should have longer, more complex digestive systems.Secondly, we studied the histological characteristics of the Gansu zokor's digestivetract and compared the differences in mocosal thickness, small intestinal villus heightand pertineter of different seasons. The histological characteristics of Gansu zokor'sgastrointestinal tract included: a. There were two different kinds ephithelium in stomachincluding keratinized stratidied squamous ephithelium and simple colummarephithelium. The number of gastric glands in stomach was large, and there werevillus-like structure in the body of stomach, b. The small intestine were longer, and theintestinal villi were higher in small intestine especially in duodenum, which changedlower and lower as it extended to the ileum, c. The cecum had thin tract wall and spiralcecal folds, d. The large intestine was relative long, and had vertical folds. The musclestrati of large intestine were thickest. The special histological characteristics of Gansuzokor's gastrointestinal tract maybe adpative to poor food condition in fieldenvironment. In spring and autumn, mocosal thickness, small intestinal villus height andpertineter were higher. The changes of histological characteristics of the Gansu zokor's digestive tract in four seasons were cinsistent with the changes of morphologicalcharacteristics.Lastly, we studied the variation of NOS neurons in the myenteric plexus of theGansu zokor's and SD rat's digestive tract under normoxia and hypoxia withNADPH-diaphorase histochemistry. There was a significant regional variation along thegastrointestinal axis in the density of NOS positive neurons: the highest was in the largeintestine, the second was in the small intestine, and the density in the stomach and thececum was lower than the small intestine. Under hypoxia, the number of NOS positiveneurons in every visual field in the gastrointestinal tract reduced, and the changes in SDrat were more significant than Gansu zokor. The feature of NOS positive neurondistribution in myenteric plexus of various segments of the Gansu zokor's digestivetract probably adapts to its feeding habit and physiological function of digest. Underhypoxia, the expression of NOS positive neurons in in every visual field in thegastrointestinal tract was lower than normoxia that maybe hypoxia influencing theanimal's metabolic rate. And facing hypoxia, adapitive ability in digestive physiologicalfunction of Gansu zoker was better.In brief, following the changes of environment, the gastrointestinal tract of Gansuzokor changed in morphological, histological and physiological characteristics whichadapts to feeding habit, food quality, energy requirement and hypoxia and that ought tobe the one of digestive measures.