5-脂氧合酶的代谢产物对大鼠垂体细胞促黄体生成素释放的外源性作用。

Exogenous action of 5-lipoxygenase by its metabolites on luteinizing hormone release in rat pituitary cells.

作者信息

Przylipiak A, Kiesel L, Habenicht A J, Przylipiak M, Runnebaum B

机构信息

Department of Gynecology and Obstetrics, University of Heidelberg, F.R.G.

出版信息

Mol Cell Endocrinol. 1990 Feb 12;69(1):33-9. doi: 10.1016/0303-7207(90)90086-n.

DOI:10.1016/0303-7207(90)90086-n

PMID:2157615

Abstract

The stimulatory effect of exogenously administered potato 5-lipoxygenase (0.1-0.3 U/2 ml) on luteinizing hormone (LH) release was demonstrated in rat anterior pituitary cells in a superfusion system. Nordihydroguaiaretic acid (NDGA), an inhibitor of 5-lipoxygenase, abolished the effect of the enzyme on LH secretion. The secretory effect on LH after 5-lipoxygenase administration was biphasic and dependent on Ca2+ indicating that 5-lipoxygenase affects LH release through its oxygenation reaction. Another series of experiments demonstrated that activation of 5-lipoxygenase, expressed as production of leukotriene (LT) B4 and C4 (728 +/- 127 pg/10(6) cells and 178 +/- 23 pg/10(6) cells, respectively) occurs in rat pituitary cells after addition of Ca2+ ionophore A23187. However, LTB4 and LTC4 were not formed by pituitary cells that had previously been desensitized by gonadotropin-releasing hormone (GnRH), the physiological ligand of LH release. These results are consistent with a role of 5-lipoxygenase metabolites in the mechanism of GnRH-induced LH secretion.

摘要

在外源给予马铃薯5-脂氧合酶（0.1 - 0.3 U/2 ml）对大鼠垂体前叶细胞促黄体生成素（LH）释放的刺激作用，在一个灌流系统中得到证实。5-脂氧合酶抑制剂去甲二氢愈创木酸（NDGA）消除了该酶对LH分泌的作用。给予5-脂氧合酶后对LH的分泌作用呈双相性且依赖于Ca2+，表明5-脂氧合酶通过其氧化反应影响LH释放。另一系列实验表明，在添加Ca2+离子载体A23187后，大鼠垂体细胞中5-脂氧合酶被激活，表现为白三烯（LT）B4和C4的产生（分别为728±127 pg/10(6)细胞和178±23 pg/10(6)细胞）。然而，先前已被促性腺激素释放激素（GnRH，LH释放的生理配体）脱敏的垂体细胞不会形成LTB4和LTC4。这些结果与5-脂氧合酶代谢产物在GnRH诱导的LH分泌机制中的作用一致。