Pituitary Response to Hypoglycemia in Pituitary Diseases[*]

Abstract

Simultaneous determinations of plasma ACTH, HGH and Cortisol were carried out in the course of an insulin tolerance test (ITT) in 7 normal subjects and in different cases of hypothalamic pathology. The parallelism observed in normal subjects between the different hormones disappeared in cases of clinical hypopituitarism with hypogonadotrophic hypogonadism: the HGH response was almost absent, whereas the ACTH response to ITT was above normal. Complete disappearance of the HGH response with very low ACTH levels was observed in 3 cases of chromophobe adenoma and in one case of hypothalamic glioma with diabetes insipidus.

The ACTH radioimmunoassay appears to be useful in the study of the pathology of the hypothalamus-pituitary-adrenal axis, mostly during dynamic tests with simultaneous measurement of other pituitary hormones. The ACTH response is more rapid, more sensitive and more reliable than the indirect Cortisol response.

Key words

ACTH - STH (HGH) - Cortisol - Insulin Tolerance test (ITT) - Hypopituitarism - Chromophobe Adenoma - Sheehan's Syndrome - Acromegaly - Gonadotrophic Insufficiency - Glioma

1 Presented in part at the round table conference "ACTH in blood", 18th Symp. Dtsch. Ges. Endokrinol., Hanover (Germany), March 1-4, 1972

1 Presented in part at the round table conference "ACTH in blood", 18th Symp. Dtsch. Ges. Endokrinol., Hanover (Germany), March 1-4, 1972