| Abstrakt: |
In order to determine whether pancreatic glucagon may influence growth of the small bowel mucosa and maturation of villous and crypt cell enzymes in orally fed rats, the hormone was administered daily to suckling pups from day 11 to day 14 (50 μg/day) and to weanling rats from day 12 to day 29 (100 μg/day) post partum. The control groups received, following the same schedule, an equal volume of 0.9% saline or of a glucagon diluent containing 0.2% phenol and 1.2% glycerine. In suckling pups treated with glucagon, sucrase and thymidine kinase activities were similar to those of the controls. During weaning, both glucagon- and diluent-treated rats grew slowlier (p < 0.05) than did saline controls. Histological examination of pancreatic -tissue sections from glucagon-treated rats showed partial or complete degranulation of the acinar cells. Compared to saline-treated controls, mucosal weight, protein and DNA per centimetre of gut remained unchanged in the duodenum, jejunum and ileum of glucagon-treated rats. However, these parameters were markedly depressed (p < 0.01) in animals treated with diluent. Prolonged treatment with glucagon during weaning had no effect on villus height, epithelial morphology and thymidine kinase activity but produced a decrease in both specific and total sucrase activity in the proximal intestine to levels about 50% (p < 0.01) of the saline controls. It is concluded that: (1) the administration of exogenous pancreatic glucagon does not induce early villous and crypt cell enzyme activity in the suckling rat; (2) at the given doses, the hormone does not impair the adaptation of the small intestine mucosa which occurs at weaning. |
