Vallet J L, Bazer F W
Department of Animal Science, University of Florida, Gainesville 32611.
J Reprod Fertil. 1989 Nov;87(2):755-61. doi: 10.1530/jrf.0.0870755.
In Exp. 1, endometrium was collected from Day-15 cyclic ewes and effects of oTP-1, oxytocin and oTP-1 + oxytocin, in various temporal relationships, on phosphatidylinositol (PI) turnover were determined. Co-treatment of endometrium with oTP-1 and oxytocin inhibited stimulatory effects of oxytocin, while treatment with oTP-1 before and during oxytocin administration had no effect. Turnover of PI was unaffected by oTP-1 alone. In Exp. 2, ovariectomized ewes were treated with progesterone (50 mg/day) for 10 days and then oestrogen (100 micrograms/day) for 2 days and endometrium was collected. Oxytocin stimulated PI turnover in endometrium, but oTP-1 had no effect alone or in combination with oxytocin. In Exp. 3, ovariectomized ewes were treated with corn oil (1 ml/day), oestrogen (50 micrograms/day), progesterone (50 mg/day) or progesterone + oestrogen for 10 days and endometrium was collected. Oxytocin stimulated PI turnover only in ewes that received progesterone. oTP-1 alone had no effect on PI turnover, while co-treatment of endometrium with oxytocin and oTP-1 stimulated PI turnover in ewes treated with progesterone, but not progesterone and oestrogen. Pretreatment of endometrium with oTP-1 stimulated PI turnover when ewes were treated with progesterone or progesterone + oestrogen. Pretreatment of endometrium with oxytocin and then treatment with oTP-1 inhibited PI turnover compared to treatment with oxytocin alone. In Exp. 4, ovariectomized ewes were treated as in Exp. 2. Catheters were placed into the uterine horns and ewes received oTP-1 into one horn and serum into the other twice daily on Days 10-12 of steroid treatment. Endometrium collected on Day 13 was used to measure PI turnover and received either no treatment or oxytocin. Oxytocin stimulated PI turnover in endometrium of these ewes and in-vivo treatment of the ewes with oTP-1 had no effect on PI turnover. These results indicate that antiluteolytic effects of oTP-1 are not mediated by inhibiting effects of oxytocin on phosphatidylinositol turnover if oxytocin receptors are present and that uterine responsiveness to oxytocin is progesterone dependent.
在实验1中，从处于发情周期第15天的母羊收集子宫内膜，测定了oTP - 1、催产素以及oTP - 1与催产素在不同时间关系下对磷脂酰肌醇（PI）周转的影响。oTP - 1与催产素共同处理子宫内膜可抑制催产素的刺激作用，而在催产素给药前及给药期间用oTP - 1处理则无影响。单独使用oTP - 1对PI周转无影响。在实验2中，对去卵巢母羊连续10天给予孕酮（50毫克/天），然后连续2天给予雌激素（100微克/天），之后收集子宫内膜。催产素可刺激子宫内膜中的PI周转，但oTP - 1单独或与催产素联合使用均无作用。在实验3中，对去卵巢母羊连续10天给予玉米油（1毫升/天）、雌激素（50微克/天）、孕酮（50毫克/天）或孕酮 + 雌激素，之后收集子宫内膜。催产素仅在接受孕酮的母羊中刺激PI周转。单独使用oTP - 1对PI周转无影响，而oTP - 1与催产素共同处理子宫内膜可刺激接受孕酮处理的母羊的PI周转，但对接受孕酮和雌激素处理的母羊无此作用。当母羊接受孕酮或孕酮 + 雌激素处理时，用oTP - 1预处理子宫内膜可刺激PI周转。与单独用催产素处理相比，先用催产素预处理子宫内膜然后用oTP - 1处理可抑制PI周转。在实验4中，对去卵巢母羊的处理同实验2。在类固醇处理的第10 - 12天，将导管插入子宫角，母羊一侧子宫角注入oTP - 1，另一侧注入血清，每日2次。第13天收集的子宫内膜用于测量PI周转，且不进行处理或给予催产素。催产素可刺激这些母羊子宫内膜中的PI周转，而母羊体内注射oTP - 1对PI周转无影响。这些结果表明，如果存在催产素受体，oTP - 1的抗黄体溶解作用不是通过抑制催产素对磷脂酰肌醇周转的作用来介导的，并且子宫对催产素的反应性依赖于孕酮。
