Day- and Nighttime Serum Melatonin in Children and Adults

Melatonin (MLT), a hormone of the pineal gland, has been suggested to inhibite sexual maturation. Recently SILMAN et al (1979) showed significantly higher serum MLT levels in prepubertal boys than in adults. LENKO et al (1980) did not confirm these results. In 107 individuals (84 children, 23 adults) we measured daytime (7.30-9 a.m.) and nighttime (10p.m.-1a.m.) serum MLT levels. The RIA of LYNCH et al (1978) with slight modifications was applied using the antibody of LEVINE et al (1975). We found widly scattered and significantly higher MLT levels in prepubertal children compared to adults (values in pg/ml):