Complex circadian regulation of pineal melatonin and wheel-running in Syrian hamsters.
Complex circadian regulation of pineal melatonin and wheel-running in Syrian hamsters.
复制标题
叙利亚仓鼠松果体褪黑激素和轮跑的复杂昼夜节律调节。
DOI：
10.1007/bf00191713
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Tamarkin,L
中科院分区：
文献类型：
--
作者：
Elliott,JA;Tamarkin,L
Circadian regulation of pineal melatonin content was studied in Syrian hamsters (Mesocricetus auratus), especially melatonin peak width and the temporal correlation to wheel-running activity. Melatonin was measured by radioimmunoassay in glands removed at different circadian times with respect to activity onset (= CT 12). Pineal melatonin peak width (h; for mean ≥125 pg/gland) and activity duration (α) were both 4–5 h longer after 12 or 27 weeks than after 5 or 6 days in continuous darkness (DD). Increased peak width was associated with a delay in the morning decline (M) of melatonin to baseline, correlated with a similar delay in wheel-running offset. In contrast, the evening rise (E) in melatonin occurred at approximately the same circadian phase regardless of the length of DD. Fifteen min light pulses produced similar phase-shifts in melatonin and activity. In a phase advance shift,Madvanced at once, whileEadvanced only after several days of adjustment. Independent timing of shifts in theEandMcomponents of the melatonin rhythm suggest that these events are controlled separately by at least two circadian oscillators whose mutual phase relationship determines melatonin peak width. This two-oscillator control of melatonin peak width is integral to the circadian mechanism of hamster photoperiodic time measurement.
