Lamsa J C, Cushman R A, Nay M G, McCracken J A
Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545.
Prostaglandins. 1992 Feb;43(2):165-79. doi: 10.1016/0090-6980(92)90084-7.
The corpus luteum (CL) of the sheep exhibits a differential sensitivity to PGF2 alpha in vivo in terms of an increase in oxytocin (OT) secretion and a decrease in progesterone secretion, pointing to the presence in vivo of both high and low affinity receptors for PGF2 alpha. The presence of the high affinity PGF2 alpha receptor was assessed by monitoring the secretion rate of OT from the ovine CL in response to subluteolytic infusions of PGF2 alpha. Rapid desensitization to PGF2 alpha occurred after only one hour of infusion, while a minimum rest period of six hours was required to restore sensitivity. The possibility that these findings could be explained by the depletion and resynthesis of OT was excluded by demonstrating an increase in OT secretion rate with supra-physiological levels of PGF2 alpha two hours after desensitization. Collectively, these results indicate the presence of a high affinity receptor for PGF2 alpha in the ovine CL which exhibits desensitization and recovery in vivo. The temporal nature of the desensitization and recovery of the high affinity PGF2 alpha receptor controlling luteal OT secretion may contribute to the pulsatile nature of PGF2 alpha release from the ovine uterus.
绵羊的黄体（CL）在体内对前列腺素F2α（PGF2α）表现出不同的敏感性，表现为催产素（OT）分泌增加和孕酮分泌减少，这表明体内存在对PGF2α的高亲和力和低亲和力受体。通过监测绵羊黄体对PGF2α亚溶解剂量输注的反应中OT的分泌率，评估高亲和力PGF2α受体的存在。输注仅1小时后，对PGF2α就出现了快速脱敏，而恢复敏感性至少需要6小时的休息期。通过在脱敏2小时后用超生理水平的PGF2α证明OT分泌率增加，排除了这些发现可能由OT的耗竭和再合成来解释的可能性。总的来说，这些结果表明绵羊黄体中存在对PGF2α的高亲和力受体，该受体在体内表现出脱敏和恢复。控制黄体OT分泌的高亲和力PGF2α受体脱敏和恢复的时间特性可能有助于PGF2α从绵羊子宫释放的脉冲性质。
