Basal stimulated prolactin levels in childhood.

Basal serum prolactin concentrations have been measured in 50 normal prepubertal children. There was no significant difference in prolactin levels between males and females and all concentrations were within the normal range for adult females (3-15 mug/l). Prolactin concentrations before and during insulin hypoglycaemia and intravenous thyrotrophin releasing hormone (TRH) have been measured in normal children of short stature, in children with isolated growth hormone (GH) deficiency and in those with hypothalamo-pituitary disease. There was no difference in either basal or stimulated prolactin levels in the normal group compared with the isolated GH-deficient group. In most of the children with hypothalamo-pituitary disease basal prolactin concentrations were within the normal range but there was an impaired response to both hypoglycaemia and TRH. Basal and stimulated levels of prolactin are compared in the same subjects with those of GH, thyroid stimulating hormone and the gonadotrophins and the clinical value of the dynamic tests described is discussed.