Moonen P, Klok G, Keirse M J
Prostaglandins. 1984 Sep;28(3):309-21. doi: 10.1016/0090-6980(84)90019-4.
Concentrations of prostaglandin endoperoxide synthase (i.e. cyclooxygenase; PGH synthase) and prostacyclin synthase (PGI synthase) were quantified with specific radioimmunometric assays in human myometrium during the last trimester of pregnancy (n = 23) and in non-pregnant controls (n = 8). Pregnant myometrium contained 3 times more PGH synthase per mg microsomal protein than non-pregnant myometrium (p less than 0.01) but there was no increase with increasing gestational age in the third trimester nor with the onset of labor. In pregnancy, as compared to the non-pregnant state, there was no significant change in the PGI synthase content of myometrial microsomes, but significantly more PGI synthase was recovered in other subcellular fractions (p less than 0.01). This suggests that pregnancy affects preferential changes in the subcellular distribution of PGI synthase in myometrial cells. Relative to its PGI synthase content pregnant myometrium contained twice as much PGH synthase as non-pregnant myometrium (p less than 0.01). This may offer further evidence that PGH synthase rather than PGI synthase itself is the rate limiting factor in myometrial PGI2 production. On the other hand, the much larger increase in PGH synthase than in PGI synthase in pregnant as compared to non-pregnant myometrium, may serve to promote preferential synthesis of prostaglandins that are potent myometrial stimulants and of critical importance in human parturition.
采用特异性放射免疫测定法，对妊娠晚期（n = 23）的人子宫肌层和非妊娠对照组（n = 8）的前列腺素内过氧化物合酶（即环氧化酶；PGH合酶）和前列环素合酶（PGI合酶）浓度进行了定量。每毫克微粒体蛋白中，妊娠子宫肌层所含的PGH合酶比非妊娠子宫肌层多3倍（p < 0.01），但在妊娠晚期，PGH合酶含量并不随孕周增加而增加，也不随分娩发动而增加。与非妊娠状态相比，妊娠时子宫肌层微粒体中的PGI合酶含量无显著变化，但在其他亚细胞组分中回收的PGI合酶显著增多（p < 0.01）。这表明妊娠影响子宫肌层细胞中PGI合酶亚细胞分布的优先变化。相对于其PGI合酶含量，妊娠子宫肌层所含的PGH合酶是非妊娠子宫肌层的两倍（p < 0.01）。这可能进一步证明，PGH合酶而非PGI合酶本身是子宫肌层PGI2产生的限速因素。另一方面，与非妊娠子宫肌层相比，妊娠子宫肌层中PGH合酶的增加幅度远大于PGI合酶，这可能有助于促进前列腺素的优先合成，这些前列腺素是强效的子宫肌层刺激剂，对人类分娩至关重要。
