Melatonin response to atrial natriuretic peptide administration in healthy volunteers.

Recent observations have demonstrated that the pineal hormone melatonin (MLT) plays a role in the neuroendocrine control of the cardiovascular system. On the other hand, it has been observed that the cardiac hormone alpha-atrial natriuretic peptide (ANP) may regulate the neuroendocrine functions. The present study was carried out to investigate the possible relationship between cardiac and pineal endocrine functions. Six healthy volunteers were treated on two different occasions with placebo or ANP at a dose of 0.1 mg i.v. as a bolus. An increase of greater than 100% in MLT serum levels was seen in 2/6 subjects. These preliminary results would suggest that ANP may play a role in the regulation of MLT secretion. Further studies will be needed to define better the cardiac-pineal interactions.