大鼠动情周期及妊娠早期卵巢中明胶酶A活性变化

VARIATION OF GELATINASES ACTIVITY IN RAT OVARY DURING ESTROUS CYCLE AND EARLY PREGNANCY

用酶谱法测定了大鼠动情周期以及正常妊娠早期和假孕早期不同时间卵巢中明胶酶A活性的变化 ,并观察了甾体激素对明胶酶A活性变化的影响。结果显示 :在不同的周期及妊娠期卵巢中均存在 6 7kD为主的明胶酶A ,但未发现有明胶酶B存在。明胶酶A活性变化如下 :1)在大鼠的动情前期明胶酶A的活性最高 ,间情期最低 ;2 )在妊娠早期(1～ 7天 )的卵巢中 ,明胶酶A的活性在妊娠第 4天达到最高 ,第 1～ 3天及第 5、 6天其活性也较高 ,但第 7天则明显下降 ;3)在假孕 (1～ 7天 )大鼠的卵巢中 ,明胶酶A的活性在假孕第 1天最高 ,第 2、 3天略下降 ,从第 4天到第 7天 ,其活性都处于较低水平 ;4)动情后期大鼠皮下注射雌二醇 (0 1mg/只 ) 2 4小时后 ,明胶酶A活性明显上升。注射孕酮则无明显变化。结果提示 :雌二醇很可能通过调节大鼠卵巢中的明胶酶A参与排卵和 /或黄体的萎缩 ;

Gelatinases were extracted from rat ovaries during estrous cycle, early pregnancy and early pseudopregnancy. Gelatinases activities were detected by zymography. The relationship between steroid hormones and ovary gelatinases activities was also observed. The results showed that active MMP2 (mainly 67 kD) existed in every sample, but another gelatinase member, MMP9, was not detected in rat ovaries. It was shown that: 1) MMP2 activity reached the highest level during proestrus, and was lowest during diestrus; 2) MM2 acti vity was increased from the first day of pregnancy, peaked on day 4 of pregnancy; but decreased significantly at day 7 of the pregnancy. 3) MMP2 activity was obviously higher on day 1 of pseudopregnancy than on the other days, and its activity decreased gradually, reached the very low level at day 4 of pseudopregnancy and maintained the low level until day 7; 4) MMP2 activity was decreased significantly 24 hours after injection of 17βestradiol ( 01 mg) at metaestrus, while MMP2 activity had no change after progesterone (04 mg) injection. These results indicate that MMP2 activity in rat ovary is regulated by estradiol during estrous cycle. It might be possible that MMP2 is involved in ovulation and/or corpus luteum atrophy and might have effects on luteum hormone secretion, therefore, involved in early pregnancy.