Thomas A, Amico J A
Department of Medicine, University of Pittsburgh School of Medicine, PA 15261, USA.
Life Sci. 1996;58(19):1615-20. doi: 10.1016/0024-3205(96)00136-1.
We previously reported that alterations in gonadal steroid hormones can influence oxytocin (OT) messenger ribonucleic acid (mRNA) expression in the hypothalamic paraventricular nucleus (PVN) of the steroid-treated ovariectomized rat, the pregnant rat, and the lactating rat. Specifically, OT mRNA in the PVN of the female rat was increased by sequential estrogen and progesterone (P) followed by withdrawal of P. In this study we investigated whether this same steroid paradigm increases OT mRNA levels in the castrate rat. Castrate rats were administered either sequential estrogen and P followed by P withdrawal or no steroid treatment prior to sacrifice. PVN OT mRNA was measured by Northern blot hybridization and pituitary OT peptide content by radioimmunoassay (RIA). The steroid-treated rats had increased OT mRNA levels compared to the sham treated rats (p < 0.04), but pituitary OT peptide content was not significantly altered. We conclude that sequential estrogen and P followed by P withdrawal increases PVN OT mRNA in the castrate, as well as the ovariectomized, rat.
我们之前报道过，性腺甾体激素的改变会影响经甾体处理的去卵巢大鼠、妊娠大鼠和泌乳大鼠下丘脑室旁核（PVN）中催产素（OT）信使核糖核酸（mRNA）的表达。具体而言，雌性大鼠PVN中的OT mRNA在先后给予雌激素和孕酮（P）然后撤去P后会增加。在本研究中，我们调查了相同的甾体模式是否会增加去势大鼠的OT mRNA水平。在处死前，给去势大鼠先后给予雌激素和P然后撤去P，或者不进行甾体处理。通过Northern印迹杂交测量PVN的OT mRNA，通过放射免疫分析（RIA）测量垂体OT肽含量。与假处理大鼠相比，经甾体处理的大鼠OT mRNA水平升高（p < 0.04），但垂体OT肽含量没有显著改变。我们得出结论，先后给予雌激素和P然后撤去P会增加去势大鼠以及去卵巢大鼠PVN中的OT mRNA。
