Sex Variation in the Activities of Mucosal Hydrolytic Enzymes in the Small Intestine of the Rat

Abstract

Mucosal response of alkaline phosphatase, ATPase and disaccharidase (lactase, maltase and trehalase) activities to sex hormones were studied by comparing male and female rats and castrated males and by injecting testosterone into castrated males. Alkaline phosphatase showed a very steep gradient in the small intestine from the oral to the aboral end, whereas ATPase activity in the ileum was still about 50 % of that in the duodenum. Both enzymes showed only minor sex variations and weak response to castration. Lactase and maltase had peak activities in the jejunum, but trehalase activity was nearly equally high in the duodenal mucosa as in the jejunum. Jejunal lactase activity was about 50 % lower in female than in male rats and castration decreased activity in males to the same low level as found in females. The administration of testosterone to castrated male rats did not enhance activity. Maltase activity showed similar sex variation, although castration was not able to decrease activity during the test period. Trehalase activity was lower in female than in male rats. The administration of testosterone enhance activity in castrated males.

Progesterone Modulation of Anaphylactically Induced Ion Transport in Uterus and Intestine

“…Evidence that the mucosae of the reproductive and gastrointestinal tracts are components of a common mucosal immune sys tem [2] suggests that hormones that affect the uterus may also influence immunity in the intestine. The potential for control of intestinal immunity by sex hormones is supported by reports that nonimmunologic functions, such as water absoiption, glucose transport, digestion and motility are in fluenced by gender [21][22][23][24][25], ovariectomy [23], steroidal contraceptives [26,28] and experimental administration of hormones [29,30], While local control of immunity by hor mones may afford distinct adaptive advantages, widespread endoctrine effects could be disadvantageous. The down- Fig.…”

“…Although steroid sex hormones regulate numerous gas trointestinal functions [21][22][23][24][25][26][27][28][29][30], and the phase 1 response of the intestine is partially suppressed by exogenous proges terone, the jejunal mucosal immune response involving type 1 hypersensitivity was generally refractory to the ef fects of progesterone. This overall conclusion is based on the (a) continued expression of anaphylaxis-mediated Cl secretion in the jejunum throughout the estrus cycle, during pregnancy and after treatment with exogenous progester one; (b) normal responsiveness of jejunal epithelium to di rect stimulation with Cl secretagogues; (c) ability o f immu nized rats to reject intestinal stages of T. spiralis following treatment with progesterone, and (d) ability of pregnant rats to develop intestinal immunity to the parasite in the face of high circulating levels of progesterone.…”