牛甲状腺前列腺素合酶的进一步特性研究。

Further characterization of bovine thyroid prostaglandin synthase.

Friedman Y, Lang M, Burke G

Biochim Biophys Acta. 1975 Aug 26;397(2):331-41. doi: 10.1016/0005-2744(75)90122-9.

Abstract

Prostaglandin synthase activity (EC 1.14.99.1) was demonstrated in bovine thyroid homogenates. 2. The synthase was characterized and shares many characteristics of the well-studied seminal vesicle enzyme and can be inhibited by indomethacin and eicosa-5,8,11,14-tetraynoic acid. 3. The enzyme is localized in the microsomal fraction and is probably associated with the plasma membranes. 4. Thyrotropin, but no other hormone tested, increased the activity of the enzyme when added to a microsomal fraction obtained from bovine thyroid. This effect is tissue-specific since thyrotropin has no effect on bovine seminal esicle or lung prostaglandin synthase. 5. Thyrotropin, cyclic AMP and the phosphodiesterase inhibitors, theophylline and quazodine increase enzyme activity when preincubated with bovine thyroid slices. 6. EDTA, when included in the pre-incubation mixture, enhances the thyrotropin effect on the enzyme but not the cyclic AMP, theophylline, or quazodine augmentation of enzyme activity in bovine thyroid slices. This suggests that phospholipase A is involved in the thyrotropin stimulation of prostaglandin formation.

摘要

在牛甲状腺匀浆中证实了前列腺素合酶活性（EC 1.14.99.1）。2. 对该合酶进行了特性鉴定，它具有许多已充分研究的精囊酶的特征，并且可被吲哚美辛和5,8,11,14-二十碳四炔酸抑制。3. 该酶定位于微粒体部分，可能与质膜相关。4. 当将促甲状腺激素添加到从牛甲状腺获得的微粒体部分时，它会增加该酶的活性，但所测试的其他激素均无此作用。这种效应具有组织特异性，因为促甲状腺激素对牛精囊或肺前列腺素合酶没有影响。5. 当与牛甲状腺切片预孵育时，促甲状腺激素、环磷酸腺苷以及磷酸二酯酶抑制剂茶碱和喹唑嗪会增加酶活性。6. 当预孵育混合物中含有乙二胺四乙酸（EDTA）时，它会增强促甲状腺激素对该酶的作用，但不会增强环磷酸腺苷、茶碱或喹唑嗪对牛甲状腺切片中酶活性的增强作用。这表明磷脂酶A参与了促甲状腺激素对前列腺素形成的刺激作用。