Reports

Melatonin: daily cycle in plasma and cerebrospinal fluid of calves

See allHide authors and affiliations

Science  18 Feb 1977:
Vol. 195, Issue 4279, pp. 686-687
DOI: 10.1126/science.841305

Abstract

Melatonin was measured by radioimmunoassay in jugular vein plasma and lateral ventricle cerebrospinal fluid collected from calves at 12 times of the day and night. Melatonin in cerebrospinal fluid increased 17-fold from an average (+/- standard error) of 38 +/- 8 picograms per milliliter during the day to an average of 637 +/- 133 picograms per milliliter during the night (P less than .001). Plasma concentrations of melatonin increased sixfold from an average, per milliliter, of 19 +/- 4 picograms during the day to 121 +/- 24 picograms during the night (P less than .001).