Johnson D C, Sashida T
J Endocrinol. 1977 Jun;73(3):463-71. doi: 10.1677/joe.0.0730463.
Pregnant mare serum gonadotrophin given intravenously to immature rats caused a maximal (x 70) increase in ornithine decarboxylase activity (ODC) at 3 h; enzyme activity declined to about ten times the control levels by 9 h and a second rise began after about 20 h. Anti-PMSG given 30 min after PMSG reduced the peak response by 70%. Actinomycin D, or cycloheximide, completely prevented an increase in ODC when given with PMSG, but only cycloheximide lowered the enzyme activity when given 18 h later. Ovine FSH plus LH also produced a peak in ODC at 3 h but the activity decreased quickly and by 9 h it was at the control level. Secretion of endogenous FSH and LH, induced by hourly injections of LH releasing hormone (LH-RH) increased ODC to the same extent as did the exogenous hormones; ODC was still higher than in the controls 4 h after the last dose of LH-RH. Increased endogenous levels of FSH and LH did not consistently raise ovarian cyclic AMP content and the increases found were much less than those obtained after injection of PMSG or FSH+LH. The results indicate that increased ODC is induced and maintained by the continual presence of gonadotrophin. The dependence of increased ODC upon increased cyclic AMP cannot be unequivocally determined because of important differences in the timing of the responses and the difficulty in determining biologically significant changes in cyclic AMP.
给未成熟大鼠静脉注射孕马血清促性腺激素（PMSG）后3小时，鸟氨酸脱羧酶（ODC）活性出现最大增幅（增至70倍）；酶活性在9小时时降至对照水平的约10倍，约20小时后开始第二次升高。在PMSG注射30分钟后给予抗PMSG，可使峰值反应降低70%。放线菌素D或环己酰亚胺与PMSG同时给予时，可完全阻止ODC活性升高，但在18小时后给予时，只有环己酰亚胺能降低酶活性。羊促卵泡素（FSH）加促黄体素（LH）也在3小时时使ODC出现峰值，但活性迅速下降，9小时时已降至对照水平。每小时注射促黄体素释放激素（LH-RH）诱导内源性FSH和LH分泌，使ODC升高的程度与外源性激素相同；在最后一剂LH-RH注射4小时后，ODC仍高于对照水平。内源性FSH和LH水平升高并未持续提高卵巢环磷酸腺苷（cAMP）含量，且所发现的升高幅度远小于注射PMSG或FSH+LH后获得的升高幅度。结果表明，ODC活性升高是由促性腺激素的持续存在诱导并维持的。由于反应时间存在重要差异以及难以确定cAMP具有生物学意义的变化，因此无法明确确定ODC活性升高对cAMP升高的依赖性。
