Cyclical variations in the abundance of leptin receptors, but not in circulating leptin, correlate with NPY expression during the oestrous cycle
Cyclical variations in the abundance of leptin receptors, but not in circulating leptin, correlate with NPY expression during the oestrous cycle
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DOI：
10.1159/000054444
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发表时间：
1999-06-01
影响因子：
4.1
通讯作者：
Robinson, ICAF
中科院分区：
文献类型：
--
作者：
Bennett, PA;Lindell, K;Robinson, ICAF
我们以前已经证明，药理剂量的雌二醇降低瘦素受体在下丘脑的表达。因此，我们分析了瘦素受体在大鼠发情周期中的表达，以确定在生理条件下雌二醇的急性变化是否会影响瘦素受体的表达。放射性原位杂交组织化学法用于测量所研究的基因表达。总瘦素受体转录水平最低的动情前期脉络丛，这些变化与循环中的雌二醇水平在大鼠4天的发情周期。与此相反，全长瘦素受体水平在弓状核和腹内侧核并不对应于总瘦素受体的水平在相同地区的下丘脑或血清雌二醇水平。弓状核瘦素受体表达与神经肽Y（NPY）表达呈负相关（r = 0.447，p < 0.05）。弓状核NPY表达与总瘦素受体表达（r = 0.080）和血清瘦素水平（r = 0.251）均无显著相关性。我们的研究结果表明，瘦素受体的表达调节在发情周期。动情周期期间血清瘦素水平的变化以及瘦素-RL和神经肽Y表达之间的相关性提供了间接证据，表明下丘脑中瘦素受体丰度的调节决定了瘦素的生物学作用。
We have demonstrated previously that pharmacological doses of oestradiol decreased leptin receptor expression in the hypothalamus. We therefore analysed leptin receptor expression during the oestrous cycle in the rat, to establish if acute changes in oestradiol affect leptin receptor expression under physiological conditions. Radioactive in situ hybridization histochemistry was used to measure the gene expression under investigation. Total leptin receptor transcript levels were lowest in prooestrus in the choroid plexus, these changes correspond inversely with levels of circulating oestradiol in the rat 4-day oestrous cycle. In contrast full-length leptin receptor levels in both arcuate and ventromedial nuclei did not correspond to the levels of total leptin receptor in the same areas of the hypothalamus or serum levels of oestradiol. Full-length leptin receptor expression in the arcuate nucleus was negatively correlated with neuropeptide Y (NPY) expression (r = 0.447, p < 0.05) in the same nucleus. Arcuate nucleus NPY expression did not correlate significantly with the expression of total leptin receptors in the arcuate nucleus(r = 0.080) or serum leptin levels (r = 0.251). Our results demonstrate that leptin receptor expression is regulated during the oestrous cycle. The unchanged serum leptin levels during the oestrous cycle together with the correlation between the expression of leptin-RL and NPY provide circumstantial evidence that regulation of leptin receptor abundance in the hypothalamus governs the biological actions of leptin.