Prolactin secretion in pubertal and adult male subjects.

Prolactin, LH and FSH circadian secretion were studied in a group of 20 boys in various pubertal stages and in 13 normal male adults. Prolactin 24-hour integrated concentration was similar in all groups except in stage 2 boys, in which it was significantly higher with respect to stage 3-4 boys. This pattern was observed also for nocturnal, but not for diurnal concentration. As already described by other authors, LH showed and amplified circadian secretion in stage 2 and 3-4 boys, particularly during night time. FSH increase was less evident, and reached the peak 24-hour mean concentration in stage 2 subjects. Our results suggest that during puberty the hypothalamic pituitary system increases its activity not only with regard to gonadotropins but also to prolactin secretion.