[Changes in pancreatic arginase activity in pubertal and adult rats induced by castration]

Arginase activity in kidney, and small intestine in several mammalian species is sensitive to castration, a finding that could suggest their dependence on testosterone. However, as far as we know, information on regulation of pancreatic arginase activity is scarce. In this paper, the effect of orchidectomy on pancreatic arginase activity in pubescent and adult rats was studied. Male pubescent and adult rats, 21 days old and 4 months old, respectively, were orquidectomizades and sacrificed at various times post-surgery. Groups of intact rats served as controls. Arginase activity and proteins were measured in pancreatic tissue. The activity of this enzyme was measured in serum in addition to glucose, triglycerides and total proteins. In pubescent rats pancreatic and serum arginase activities peaked at day 5 post-surgery, increased arginase activity in adult rats was seen at day 20. Changes in serum and pancreatic proteins in pubescent, but not in adult, castrated rats were observed. Taken together, these results suggest that pancreatic arginase activity is androgen-dependent and that there is age-difference, probably due lo distinct patterns of hormone secretion in pubescent and adult rats.