Larson L, Olofsson J, Hellberg P, Brannstrom M, Selstam G, Hedin L
Department of Physiology, University of Goteborg, Sweden.
Prostaglandins. 1991 Feb;41(2):111-21. doi: 10.1016/0090-6980(91)90024-a.
Luteinizing hormone (LH) stimulates prostaglandin biosynthesis and steroidogenesis in preovulatory (PO) follicles prior to ovulation. Since the ovulatory process shares many similarities with an inflammatory reaction, mediators of the inflammatory response, such as bradykinin (BK) have been suggested to modulate the effects of LH. In the present study the effect of BK (5 microM) on: 1) prostaglandin biosynthesis (PGE2, PGF2 alpha and 6-keto-PGF1 alpha), 2) the levels of two enzymes in the cyclo-oxygenase pathway, prostaglandin endoperoxide synthase (PGS) and prostacyclin synthase (PCS), and 3) cyclic adenosine 3'5'-monophosphate (cAMP) and progesterone response of PO follicles incubated in vitro were examined. LH (0.1 microgram/ml) stimulated the accumulation of cAMP and progesterone in the medium, while BK had no effect on these parameters. BK exerted a slight stimulatory effect on PGE2, and PGF2 alpha, (p less than or equal to 0.01) but not on 6-keto-PGF1 alpha synthesis, but no changes in PGS or PCS levels could be detected. The effect of LH on prostaglandin biosynthesis was much more pronounced, with an increase of PGE2, PGF2 alpha and 6-keto-PGF1 alpha. LH also induced PGS. The combination of LH and BK did not alter these responses compared to that of LH alone. This study demonstrates that BK stimulates prostaglandin biosynthesis in PO follicles. In contrast to LH, this effect of BK does not seem to involve the adenylate cyclase system, since BK did not stimulate cAMP production. BK did not affect the levels of PGS or PCS, and the stimulatory effect of BK is suggested to involve an increase in the availability of substrate for the cyclo-oxygenase pathway.
促黄体生成素（LH）在排卵前刺激排卵前（PO）卵泡中的前列腺素生物合成和类固醇生成。由于排卵过程与炎症反应有许多相似之处，因此有人提出炎症反应的介质，如缓激肽（BK）可调节LH的作用。在本研究中，研究了BK（5 microM）对以下方面的影响：1）前列腺素生物合成（PGE2、PGF2α和6-酮-PGF1α）；2）环氧化酶途径中两种酶，前列腺素内过氧化物合酶（PGS）和前列环素合酶（PCS）的水平；3）体外培养的PO卵泡的环磷酸腺苷（cAMP）和孕酮反应。LH（0.1微克/毫升）刺激培养基中cAMP和孕酮的积累，而BK对这些参数没有影响。BK对PGE2和PGF2α有轻微的刺激作用（p≤0.01），但对6-酮-PGF1α的合成没有影响，并且未检测到PGS或PCS水平的变化。LH对前列腺素生物合成的影响更为明显，PGE2、PGF2α和6-酮-PGF1α均增加。LH还诱导了PGS。与单独使用LH相比，LH和BK的组合并未改变这些反应。本研究表明，BK刺激PO卵泡中的前列腺素生物合成。与LH不同，BK的这种作用似乎不涉及腺苷酸环化酶系统，因为BK没有刺激cAMP的产生。BK不影响PGS或PCS的水平，并且BK的刺激作用被认为涉及环氧化酶途径底物可用性的增加。
