Kawai Y, Clark M R
Endocrinology. 1985 Jun;116(6):2320-6. doi: 10.1210/endo-116-6-2320.
Tumor-promoting phorbol esters are believed to affect cell functions by activating a Ca+2- and lipid-dependent protein kinase (protein kinase C). Since such protein kinases may be involved in ovarian granulosa cell metabolism, the effects of phorbol esters on prostaglandin (PG) and progesterone (P) accumulation were investigated. Cells were obtained from immature (28-29 days old) rats 48 h after injection of 20 IU PMSG and incubated for up to 5 h. A tumor-promoting phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate (TPA), at a concentration of 25 ng/ml, caused 4-fold increases in PGE and 6-keto-PGF1 alpha accumulation at 5 h. LH (10 ng/ml) caused 7- and 4-fold increases in PGE and 6-keto-PGF1 alpha accumulation, respectively. When tested in combination, the increases in PGE and 6-keto PGF1 alpha due to TPA and LH were additive. Like the effect of LH, the TPA stimulation of PG synthesis occurred after a delay of 2-3 h. By 5 h of incubation, cells exposed to TPA exhibited increased PG synthase activity in whole homogenates. TPA caused a smaller (2-fold) increase in P accumulation than was observed with LH (10-fold). When tested in combination, however, TPA decreased the P response to LH by approximately 25%. These effects of TPA on basal and LH-stimulated PG and P accumulation were very similar to the actions of GnRH. We, therefore, investigated the effect of exposure to the combination of GnRH and TPA. A GnRH agonist, [D-Ala6,des-Gly-NH2(10)] GnRH ethylamide (GnRHa; 10 ng/ml) caused a 4-fold increase in PGE accumulation. The effect of TPA on PGE accumulation was also additive to that of GnRHa. TPA, on the other hand, did not affect the 2.5-fold P response to GnRHa. Neither stimulation or inhibition of PGE or P accumulation was observed in the presence of a nontumor-promoting phorbol ester. Furthermore, TPA did not affect basal or LH-stimulated cAMP accumulation or basal or LH-stimulated protein kinase A activity. These data indicate that protein kinase C activation can influence granulosa cell PG and P accumulation.
促肿瘤佛波酯被认为通过激活一种钙和脂质依赖性蛋白激酶（蛋白激酶C）来影响细胞功能。由于这类蛋白激酶可能参与卵巢颗粒细胞的代谢，因此研究了佛波酯对前列腺素（PG）和孕酮（P）积累的影响。从注射20国际单位孕马血清促性腺激素（PMSG）48小时后的未成熟（28 - 29日龄）大鼠获取细胞，并孵育长达5小时。一种促肿瘤佛波酯，12 - O - 十四烷酰佛波醇13 - 乙酸酯（TPA），浓度为25纳克/毫升，在5小时时使前列腺素E（PGE）和6 - 酮 - 前列腺素F1α（6 - keto - PGF1α）的积累增加了4倍。促黄体生成素（LH，10纳克/毫升）分别使PGE和6 - keto - PGF1α的积累增加了7倍和4倍。当联合测试时，TPA和LH引起的PGE和6 - 酮 - PGF1α的增加是相加的。与LH的作用一样，TPA对PG合成的刺激在延迟2 - 3小时后出现。到孵育5小时时，暴露于TPA的细胞在全匀浆中显示出PG合酶活性增加。TPA使P的积累增加幅度较小（2倍），而LH引起的增加幅度为10倍。然而，联合测试时，TPA使P对LH的反应降低了约25%。TPA对基础及LH刺激的PG和P积累的这些影响与促性腺激素释放激素（GnRH）的作用非常相似。因此，我们研究了暴露于GnRH和TPA组合的影响。一种GnRH激动剂，[D - Ala6，des - Gly - NH2(10)]GnRH乙酰胺（GnRHa，10纳克/毫升）使PGE的积累增加了4倍。TPA对PGE积累的影响与GnRHa的影响也是相加的。另一方面，TPA不影响对GnRHa的2.5倍P反应。在存在非促肿瘤佛波酯的情况下，未观察到对PGE或P积累的刺激或抑制作用。此外，TPA不影响基础或LH刺激的环磷酸腺苷（cAMP）积累，也不影响基础或LH刺激的蛋白激酶A活性。这些数据表明蛋白激酶C的激活可影响颗粒细胞PG和P的积累。
