COMPARATIVE DIABETOGENIC ACTION OF THE HYPOPHYSIS FROM VARIOUS ANIMALS

Abstract

Presenting the difficulties and pecularities of various test animals observed in over 10 yrs. of exptl. observations, the rationale is given for the selection of (1) normal dogs, (2) hypophysectomized dogs with the pancreas reduced to 4 g., and (3) toads deprived of hypophysis and pancreas, for bio-assay of the diabetogenic factor. Correlation with glycosuria and ketonuria led to the use of hyperglycemia (150 mg. % or more in the fasting state, Hagedorn method) as an index of diabetogenic action. Extracts of hypophyses from fish, toad, hen, rat, guinea pig, dog, beef and man were injected intraperit. for from 1 to 4 days. The diabetogenic power of the ant. hypophyses which were studied can be placed in the following order of decreasing activity, tested on toads deprived of their hypophysis and pancreas: human, dog, toad, rat, guinea pig, chicken (whole hypophysis), ox, snake, and corvina (Micropogon opercularis). Tested in the dog a similar order could be established for the extracts of hypophyses from human, toad, rat, chicken and beef origins. The relative potency of dog hypophysis was not precisely established. Failure to demonstrate the diabetogenic action of hypophysis from the guinea pig and fish was probably due to relatively insufficient dosage. Cortico-sterone and desoxycortico-sterone failed to produce a diabetogenic effect. For testing extracts of mammalian origin the hypophysectomized dog with pancreas reduced to 4 gm. is the test animal of choice.