Effects of photoperiod and temperature on rhythmic melatonin secretion from the pineal organ of the white sucker (Catostomus commersoni) in vitro.

摘要: The secretion rate of melatonin from cultured pineal organs the white sucker was examined for several days under either a 12:12-hr light:dark (LD) cycle or continuous darkness (DD) at 10 degrees 20 degrees. incubation medium changed 3-hr intervals and secreted measured by RIA. Under LD (0800 light on, 2000 off) suppressed during day highly active night, with larger amplitudes than In DD no circadian rhythmicity in found October January, whereas circadian-like pattern detected pineals which were derived animals reared 1 week prior to experiment January. still responded an additional 24-hr both temperatures even after 6 more days. These results clearly reveal influence photoperiod temperature on organ-cultured glands. existence oscillator gland is suggested.