The effect of insulin insufficiency on plasma thyroid hormones and some metabolic constituents in Pacific hagfish, Eptatretus stouti.

The effect of guinea pig anti-human insulin serum was studied in Pacific hagfish. The metabolic indicators of insulin insufficiency, such as elevation of plasma glucose, free fatty acids, and alpha-amino nitrogen levels were obtained at 72 and 120 hr after anti-insulin serum injection. Plasma triiodothyronine levels declined significantly 24 hr after anti-insulin serum administration. These findings supplement earlier data with the same species and suggest that the regulatory metabolic action of insulin and thyroid hormones are related in cyclostomes.