Bartness T J, Bittman E L, Wade G N
Brain Res Bull. 1985 May;14(5):427-30. doi: 10.1016/0361-9230(85)90020-6.
Lesions of the paraventricular nucleus (PVN) of the hypothalamus block short photoperiod-induced testicular regression in Syrian hamsters. We examined the effects of PVN or sham lesions on the short photoperiod-induced increases in body weight and adiposity in female Syrian hamsters. PVN lesions did not affect body weight when hamsters were housed in a long photoperiod (LD, 16:8) and fed Purina laboratory rodent chow (No. 5001). However, when fed a high-fat diet both groups gained weight, and the hamsters with PVN lesions gained approximately twice as much as the sham-operated controls. When the hamsters were exposed to a short photoperiod (LD, 8:16), only the hamsters with sham lesions displayed the typical increase in body weight. No further increase in body weight or parametrial fat pad weight was seen when the hamsters with PVN lesions were exposed to the short photoperiod. The lack of a short photoperiod-induced increase in body weight gain in hamsters with PVN lesions seems unlikely to be due to a "ceiling effect" on body weight gain because we have routinely observed neurally intact, melatonin-treated female Syrian hamsters with body weight in excess of 250 g. Finally, the short photoperiod interrupted estrous cyclicity in sham-lesioned hamsters but not in those with PVN lesions. Thus, PVN lesions exaggerate dietary obesity but prevent short photoperiod-induced weight gains and vaginal acyclicity in female Syrian hamsters.
下丘脑室旁核（PVN）损伤可阻止短光照周期诱导的叙利亚仓鼠睾丸退化。我们研究了PVN损伤或假损伤对短光照周期诱导的雌性叙利亚仓鼠体重增加和肥胖的影响。当仓鼠饲养在长光照周期（LD，16:8）并喂食普瑞纳实验室啮齿动物饲料（5001号）时，PVN损伤不影响体重。然而，当喂食高脂饮食时，两组仓鼠体重均增加，且PVN损伤的仓鼠体重增加量约为假手术对照组的两倍。当仓鼠暴露于短光照周期（LD，8:16）时，只有假损伤的仓鼠体重出现典型增加。PVN损伤的仓鼠暴露于短光照周期时，体重或子宫旁脂肪垫重量未见进一步增加。PVN损伤的仓鼠缺乏短光照周期诱导的体重增加，似乎不太可能是由于体重增加的“天花板效应”，因为我们经常观察到神经完整、经褪黑素处理的雌性叙利亚仓鼠体重超过250克。最后，短光照周期中断了假损伤仓鼠的发情周期，但未中断PVN损伤仓鼠的发情周期。因此，PVN损伤会加剧饮食性肥胖，但可防止短光照周期诱导的雌性叙利亚仓鼠体重增加和阴道无周期性变化。
