EVALUATION OF PITUITARY-ADRENAL FUNCTION IN CHILDREN
ABSTRACT The reactivity of the hypothalamico-pituitary-adrenal axis was determined in 48 children, not suffering from any endocrine disorder. The free cortisol (F)- and corticosterone (B) content of plasma was determined in response to ACTH (clinical corticotrophin; A1 peptide), a corticotrophin releaser (lysine vasopressin) and a non specific stimulus (bacterial polysaccharide) as compared to saline. The two ACTH-preparations infused over one hour in a dose of 5 IU per child elicited a marked increase in both F and B. Lysine vasopressin in a dose of 0.5 IU per year of age similarly infused, exhibited a distinct linear increase in the two circulating cortical steroids, although the effect of this octapeptide was smaller than that of the two ACTH-preparations. Blood pressure was also measured during the infusion with vasopressin or saline. The systolic blood pressure was not significantly affected by vasopressin, but a significant rise in diastolic blood pressure was found. No correlation between the increase in diastolic blood pressure and in blood corticoids in response to vasopressin, was found. The intravenous administration of a relatively small amount of pyrifer caused a moderate increase in circulating F which was significant only at 4 and 6 hours after the injection of the pyrogen. The B content did not increase significantly above that of saline treated control children, presumably because of the relatively weak corticotrophic activity of the pyrogen under these conditions. A positive linear relation between body temperature and time was found. No correlation between increase in body temperature and increase in circulating F could be demonstrated.