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
