未成熟、青春期及假孕大鼠卵巢鸟氨酸脱羧酶的调节
Ovarian ornithine decarboxylase regulation in the immature, the pubescent, and the pseudopregnant rat.
作者信息
Nureddin A
出版信息
Proc Natl Acad Sci U S A. 1978 May;75(5):2530-4. doi: 10.1073/pnas.75.5.2530.
Ovarian ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) regulation was investigated in immature, pubescent, and pseudopregnant rats. After initial induction of the enzyme by injection of lutropin in the immature rat, continued daily injections resulted in a graded decrease in the activity of the enzyme. In the 32-day-old rat, the induction and subsequent decline in enzymic activity after a single injection of lutropin could only be partially reversed by injections of the hormone at 4-hr intervals. This decrease could not be attributed to a decrease in ovarian in vivo uptake of the hormone. In the pseudopregnant rat, ovarian ornithine decarboxylase is highly refractory to induction by either a single injection or repeated injections of lutropin. This refractoriness occurs despite a 2- to 3-fold increase in ovarian in vivo uptake of the hormone compared to that in the 32-day-old rat. It is suggested that the refractoriness observed with all three tissues is a function of cell differentiation.
研究了未成熟、青春期和假孕大鼠卵巢鸟氨酸脱羧酶（L-鸟氨酸羧基裂解酶，EC 4.1.1.17）的调节情况。在未成熟大鼠中通过注射促黄体激素初步诱导该酶后，持续每日注射会导致酶活性逐渐下降。在32日龄大鼠中，单次注射促黄体激素后酶活性的诱导及随后的下降，仅通过每隔4小时注射该激素能部分逆转。这种下降不能归因于卵巢对该激素体内摄取的减少。在假孕大鼠中，卵巢鸟氨酸脱羧酶对单次注射或重复注射促黄体激素的诱导具有高度抗性。尽管与32日龄大鼠相比，该激素在卵巢的体内摄取增加了2至3倍，但仍出现这种抗性。提示在所有这三种组织中观察到的抗性是细胞分化的一种功能。
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