Du Y, Wade G N, Blaustein J D
Neuroscience and Behavior program, University of Massachusetts, Amherst 01003-7710, USA.
Am J Physiol. 1996 May;270(5 Pt 2):R978-83. doi: 10.1152/ajpregu.1996.270.5.R978.
Food deprivation, as well as treatment with metabolic inhibitors, suppress steroid hormone-induced estrous behavior in ovariectomized (OVX) Syrian hamsters. Previous work indicates that 48 h of food deprivation decreases the number of detectable estrogen receptor immunoreactive (ERIR) cells in the ventromedial hypothalamus (VMH) and the area just lateral to it (VLH), increases the number of ERIR cells in the medial preoptic area (MPO), and has no effect on the number of ERIR cells in the nucleus of the solitary tract in OVX hamsters. The present study examined the effects of food deprivation on neural progestin receptor binding using an in vitro binding assay and on progestin receptor immunoreactivity (PRIR) in estradiol-primed, OVX hamsters. Parallel behavior tests for sexual behavior were also performed in both experiments. OVX hamsters received 2.5 micrograms estradiol benzoate and were fed ad libitum or food deprived at the same time. Forty-eight hours later, animals were killed in preparation for the immunocytochemistry or progestin receptor assay. Binding assays indicated that 48-h food deprivation decreased progestin receptor levels in the preoptic area and had no effect in the mediobasal hypothalamus, an area that includes the VMH and the arcuate nucleus (ARH). Immunocytochemical analysis confirmed these findings. Food deprivation caused a decrease in sexual receptivity and in the number of detectable PRIR cells in the MPO and medial amygdala but had no effect on the number of detectable PRIR cells in the VMH/VLH, the ARH, or the anteroventral periventricular nucleus. These results suggest that food deprivation modulates progestin receptor binding and PRIR in a site-specific manner. In addition, the effects of food deprivation on neural ERIR and PRIR are significantly different.
食物剥夺以及用代谢抑制剂进行处理，会抑制卵巢切除（OVX）的叙利亚仓鼠中类固醇激素诱导的发情行为。先前的研究表明，48小时的食物剥夺会减少腹内侧下丘脑（VMH）及其外侧区域（VLH）中可检测到的雌激素受体免疫反应性（ERIR）细胞数量，增加内侧视前区（MPO）中ERIR细胞的数量，并且对OVX仓鼠孤束核中ERIR细胞的数量没有影响。本研究使用体外结合测定法研究了食物剥夺对神经孕激素受体结合的影响，以及对经雌二醇预处理的OVX仓鼠中孕激素受体免疫反应性（PRIR）的影响。在两个实验中还同时进行了性行为的平行行为测试。OVX仓鼠接受2.5微克苯甲酸雌二醇，并随意进食或同时进行食物剥夺。48小时后，处死动物以准备进行免疫细胞化学或孕激素受体测定。结合测定表明，48小时的食物剥夺会降低视前区的孕激素受体水平，而对包括VMH和弓状核（ARH）在内的中基底下丘脑没有影响。免疫细胞化学分析证实了这些发现。食物剥夺导致性接受能力下降，以及MPO和内侧杏仁核中可检测到的PRIR细胞数量减少，但对VMH/VLH、ARH或室周前腹核中可检测到的PRIR细胞数量没有影响。这些结果表明，食物剥夺以位点特异性方式调节孕激素受体结合和PRIR。此外，食物剥夺对神经ERIR和PRIR的影响显著不同。
