Serum melatonin and 6-sulfatoxymelatonin in end-stage renal disease: effect of hemodialysis.

The pineal hormone melatonin plays a role in the regulation of hypothalamic-pituitary axis, target gland function, sleep pattern, mood changes, cellular immunity, antibody response, and skin pigmentation, nearly all of which are also affected by renal insufficiency. We measured serum melatonin and its main urinary metabolite, 6-sulfatoxymelatonin (6-SM), by radioimmunoassay in 11 patients with end-stage renal disease (ESRD) between the hours of 6 and 9 a.m.