Kisielewska J, Flint A P, Ziecik A J
Division of Reproductive Endocrinology and Pathophysiology, Polish Academy of Sciences, Olsztyn, Poland.
J Endocrinol. 1996 Jan;148(1):175-80. doi: 10.1677/joe.0.1480175.
Although the uterus is a target tissue for LH and its homologue hCG the second messenger system responding to LH/hCG in myometrial cells is not established. In this study we investigated the involvement of protein kinase A and protein kinase C in the action of hCG on porcine myometrial smooth muscle cells in vitro. Myometrium was obtained from ovariectomized gilts given 2.5 mg oestradiol benzoate plus 50 mg progesterone for five consecutive days. Myometrial cells were cultured for 48 h and different doses of hCG were then added. Increasing doses of hCG stimulated concentration-dependent increases in [3H]inositol phosphates (IPs) accumulation in incubations lasting 24 h. The highest dose of hCG (1000 mU/ml) increased turnover of IPs by 2.4-fold as reflected in elevations in IP1, IP2 and IP3, and similar effects were observed with noradrenaline. The time- and concentration-dependent effects of hCG on IPs accumulation occurred between 16 and 24 h of incubation. Incubation of myocytes with the lowest doses of hCG (0.1 and 1 mU/ml) caused a significant increase in cAMP accumulation but the highest doses (10-1000 mU/ml) had no effect on cAMP concentrations. This is the first demonstration that LH/hCG receptor signalling leads to increased inositol phosphate turnover in myometrial cells as well as cAMP generation and it leads to the conclusion that both protein kinase A and protein kinase C signalling mechanisms are involved in gonadotrophin action in porcine myometrial smooth muscle cells.
尽管子宫是促黄体生成素（LH）及其同源物人绒毛膜促性腺激素（hCG）的靶组织，但子宫肌层细胞中响应LH/hCG的第二信使系统尚未明确。在本研究中，我们调查了蛋白激酶A和蛋白激酶C在hCG对猪子宫肌层平滑肌细胞作用中的参与情况。子宫肌层取自连续五天给予2.5mg苯甲酸雌二醇加50mg孕酮的去卵巢小母猪。子宫肌层细胞培养48小时后，加入不同剂量的hCG。在持续24小时的孵育中，hCG剂量增加刺激了[3H]肌醇磷酸（IPs）积累呈浓度依赖性增加。最高剂量的hCG（1000mU/ml）使IPs周转率增加了2.4倍，这体现在IP1、IP2和IP3的升高上，去甲肾上腺素也观察到类似效果。hCG对IPs积累的时间和浓度依赖性效应发生在孵育16至24小时之间。用最低剂量的hCG（0.1和1mU/ml）孵育心肌细胞导致cAMP积累显著增加，但最高剂量（10 - 1000mU/ml）对cAMP浓度没有影响。这首次证明LH/hCG受体信号传导导致子宫肌层细胞中肌醇磷酸周转率增加以及cAMP生成增加，并且得出结论：蛋白激酶A和蛋白激酶C信号传导机制均参与猪子宫肌层平滑肌细胞中的促性腺激素作用。
