Daily Variation in Concentration of Cortisol in Plasma in Intact and Hypophysectomized Gulf Killifish

See allHide authors and affiliations

Science  14 Jul 1972:
Vol. 177, Issue 4044, pp. 185-187
DOI: 10.1126/science.177.4044.185


A daily variation in concentration of cortisol in plasma is synchronized by a 12-hour daily photoperiod in intact as well as in hypophysectomized fish. The daily rhythm in concentration of the adrenal steroid does not depend on a daily rhythm in the concentration of pituitary adrenocorticotropic hormone.