Excessive Glucagon Responses to Arginine in Active Acromegaly[*]

Abstract

The glucagon response to an arginine infusion was studied in active acromegalic patients as well as in inactive acromegalics and normal subjects. Basal glucagon levels were found to be similar. By contrast the active patients demonstrated higher peak values after arginine infusions than did the other two groups. Blunting of the glucagon response to arginine was noted in patients with inactive acromegaly. In one patient studied before and after treatment, at a time when panhypopituitarism had supervened, no glucagon or insulin response to infused arginine could be elicited. It was concluded that growth hormone is probably required for optimum islet of Langerhans function and that excess growth hormone production will cause excessive glucagon secretion which may contribute to the diabetic diathesis in active acromegaly.

Key words

Glucagon Response - Arginine - Acromegaly - Growth Hormone

1 This study was supported by U.S.P.H.S. Training Grant TO 1-Am05170 and Fisher Endocrine Research Fund. Metabolic studies were performed in the Clinical Research Center supported by RR-55.

1 This study was supported by U.S.P.H.S. Training Grant TO 1-Am05170 and Fisher Endocrine Research Fund. Metabolic studies were performed in the Clinical Research Center supported by RR-55.

2 Present address: Diabetes Section, Clinical Endocrinology Branch, National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland 20014, U.S.A.