Coirini H, Schumacher M, Flanagan L M, McEwen B S
Laboratory of Neuroendocrinology, Rockefeller University, New York, New York 10021.
J Neurosci. 1991 Nov;11(11):3317-24. doi: 10.1523/JNEUROSCI.11-11-03317.1991.
The modulation of oxytocin (OT) receptors (OTRs) by estrogen was investigated in the ventromedial hypothalamus by in vitro receptor autoradiography. Treatment of ovariectomized and adrenalectomized rats with various doses of estradiol benzoate (EB) increased OTR binding not only in the ventromedial nuclei of the hypothalamus (VMN), but also in the area lateral to the nuclei (IVMN). After a single injection of EB, OTRs first were induced within the ventrolateral parts of the VMN, and only hours later they appeared in the IVMN. This is consistent with the interpretation that OTRs are first induced within the estrogen-sensitive neurons of the ventrolateral VMN and then are transported laterally out of the nuclei. Two additional experiments confirmed this interpretation. First, local infusion of a low dose (10 micrograms) of the neuronal transport inhibitor vinblastine blocked the appearance of OTRs in the IVMN but did not prevent the induction of OTRs by EB within the nuclei. Second, a knife cut placed lateral to the VMN prevented the spread of OTRs out of the nuclei. However, even after treatment with a high dose of EB (2 x 10 micrograms), progesterone (P) was required for a maximal extension of the area covered by OTRs. Thus, the OTR is an estrogen-induced neurotransmitter receptor that is transported to its site of action, the lateral ventromedial hypothalamus, where it is modulated by P and where estrogen-induced OT immunoreactivity is found.
通过体外受体放射自显影技术，研究了雌激素对腹内侧下丘脑催产素（OT）受体（OTRs）的调节作用。用不同剂量的苯甲酸雌二醇（EB）处理去卵巢和肾上腺切除的大鼠，不仅增加了下丘脑腹内侧核（VMN）的OTR结合，还增加了核外侧区域（IVMN）的OTR结合。单次注射EB后，OTRs首先在VMN的腹外侧部分被诱导，数小时后才出现在IVMN中。这与以下解释一致，即OTRs首先在腹外侧VMN的雌激素敏感神经元中被诱导，然后从核中横向转运出来。另外两个实验证实了这一解释。首先，局部注入低剂量（10微克）的神经元运输抑制剂长春碱可阻止OTRs在IVMN中的出现，但不阻止EB在核内诱导OTRs。其次，在VMN外侧进行的一刀切割可阻止OTRs从核中扩散。然而，即使在用高剂量EB（2×10微克）处理后，孕激素（P）对于OTRs覆盖区域的最大扩展也是必需的。因此，OTR是一种雌激素诱导的神经递质受体，它被转运到其作用部位，即下丘脑腹内侧外侧，在那里它受到P的调节，并且在那里发现雌激素诱导的OT免疫反应性。
