Hypertrophy of the islets of Langerhans of frog tadpoles after partial pancreatectomy This investigation was supported by Grant AM-05818 from the Public Health Service, and by a grant from the Rackham School of Graduate Studies, University of Michigan.

Abstract

Subsequent to incomplete surgical removal of the dorsal pancreatic rudiment of Rana pipiens embryos, islets of Langerhans arise in the pancreas, but in smaller amount than normal. Conpensatory hypertrophy of the beta cells occurs, and the islets are transformed from a larval into an adult histological type. Larval growth and metamorphosis is otherwise unaffected. The evidence supports the hypothesis that metamorphic maturation of the islets of Langerhans is a consequence of an increase in the functional demand on the islets of the frog as compared to the tadpole, and not to direct metamorphic effects of thyroxine. Possible causes for a relatively higher insulin requirement of the frog include (1) an increase in the carbohydrate load on the islets, (2) an increase in the secretion of hyperglycemic hormones, and (3) a higher rate of insulin inactivation.