Horton T H, Buxton O M, Losee-Olson S, Turek F W
Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA.
Horm Behav. 2000 Jun;37(4):388-98. doi: 10.1006/hbeh.2000.1592.
Serum leptin concentrations were obtained from male Siberian hamsters (Phodopus sungorus) and golden hamsters (a.k.a. Syrian, Mesocricetus auratus) housed on long [light:dark (LD) 16:8] and short (LD 6:18) photoperiods for 10-11 weeks. Blood samples were collected at 45-min intervals for 24 h from individual animals using an in-dwelling atrial catheter. In Siberian hamsters, exposure to short photoperiods as compared to long photoperiods reduced body weight (32.5 +/- 1.5 vs 47.7 +/- 1.1 g) and leptin (24-h mean: 5.3 +/- 0.4 ng/ml vs 18.6 +/- 2.1 ng/ml). Although photoperiod influenced the temporal distribution of leptin in golden hamsters, the main effect of photoperiod on leptin levels in golden hamsters did not reach significance (24-h mean: 7.1 +/- 1.0 ng/ml vs 5.1 +/- 0.8 ng/ml.). Body weights of golden hamsters did not vary significantly following exposure to short photoperiod for 11 weeks (178.3 +/- 3.6 g in LD 6:18 vs 177.8 +/- 7.3 g in LD 16:8). There was no nocturnal increase in serum leptin in either species. Marked interindividual differences were apparent in individual leptin profiles. Periodogram analysis revealed that only a few animals exhibited 24-h periodicities; the presence of a significant 24-h periodicity was more common in hamsters exposed to short days. Photoperiod-associated differences in the 24-hour profile of leptin secretion may be the result of photoperiod-associated changes in feeding behavior or metabolism. A full understanding of the regulation of leptin secretion in multiple time domains may enhance our understanding of the function of leptin.
从饲养在长光照周期[光照：黑暗（LD）16:8]和短光照周期（LD 6:18）下10 - 11周的雄性西伯利亚仓鼠（Phodopus sungorus）和金黄仓鼠（又名叙利亚仓鼠，Mesocricetus auratus）中获取血清瘦素浓度。使用留置心房导管，每隔45分钟从个体动物采集血样，持续24小时。在西伯利亚仓鼠中，与长光照周期相比，短光照周期使体重降低（32.5±1.5克对47.7±1.1克），瘦素水平也降低（24小时平均值：5.3±0.4纳克/毫升对18.6±2.1纳克/毫升）。虽然光照周期影响金黄仓鼠瘦素的时间分布，但光照周期对金黄仓鼠瘦素水平的主要影响未达到显著水平（24小时平均值：7.1±1.0纳克/毫升对5.1±0.8纳克/毫升）。暴露于短光照周期11周后，金黄仓鼠的体重没有显著变化（LD 6:18条件下为178.3±3.6克，LD 16:8条件下为177.8±7.3克）。两种仓鼠的血清瘦素在夜间均无升高。个体瘦素谱存在明显的个体间差异。周期图分析显示，只有少数动物表现出24小时周期性；在短日照条件下的仓鼠中，显著的24小时周期性更为常见。瘦素分泌24小时谱中与光照周期相关的差异可能是光照周期相关的摄食行为或代谢变化的结果。全面了解多时间域中瘦素分泌的调节可能会增进我们对瘦素功能的理解。
