Skochko N. Secretory and absorbtive function of the gastrointestinal tract in rats through ontogenesis

The thesis is devoted to the study of the secretory function of the stomach and transport of water and electrolytes across the epithelium of the rats colon at different ages. The results showed that basal acid output in the stomach of young rats increased by 408.6% compare to juvenile rats. In all other age groups (early and late mature, elderly and senile rats) basal acid output in the stomach reduced by 2 times compared to young rats. Carbacholin stimulated acid output increased at all age groups in comparison with juvenile rats, except senile age. Acid output of senile rats didn't significantly differ from juvenile age. Basal pepsin output of young rats was the same as in juvenile. In early matured rats it decreased by 38.4% (p<0,05) compare to juvenile and remained essentially unchanged until the end of life. Carbacholin stimulated pepsin output of rats didn't change until they reached the early mature age. In eldery carbacholin stimulated pepsin output decreased by 26,7% (p<0,05) compare to juvenile and remained unchanged in elderly rats. Absorption of water and Na+, Cl- ions increased in colon of elderly and senile, but secretion of K+ remained constant. In colon fecal bioptate of senile rats reduced Bacteroides quantity, increased number of E. coli with normal and altered enzymatic properties, opportunistic enterobacteria, Clostridium and Candida yeasts. In blood serum, organs of the digestive tract of rats with age pro/antioxidant balance disturbed, the content of lipid peroxidation products increased and antioxidant enzymes diminished. Periodic multiprobiotic administration along the life resulted in normalization of basal and carbacholin stimulated acid output, had no effect on pepsin output, enhance secretion of water Na+, Cl- ions across the epithelium of the colon. Also "Symbiter", prolongated medium life expectancy and reduced the concentration of urea nitrogen, biomarkers of aging, in senile rats. In experimental group of senile age concentration of urea nitrogen decreased in comparison with control group of same age and didn't differ from younger animals.