前列腺素Fα对犬甲状腺环磷酸腺苷水平及功能的影响。

Effects of prostaglandins F alpha on dog thyroid cyclic AMP level and function.

作者信息

van Sande J, Cochaux P, Decoster C, Boeynaems J M, Dumont J E

出版信息

Biochim Biophys Acta. 1982 May 5;716(1):53-60. doi: 10.1016/0304-4165(82)90202-1.

Abstract

Prostaglandins F1 alpha and F2 alpha, at high concentrations (greater than or equal to 28 microM) enhanced cyclic AMP accumulation in dog thyroid slices. At lower concentrations, they inhibited the cyclic AMP accumulation induced by thyrotropin (TSH), prostaglandin E1, and cholera toxin. This effect was rapid in onset and of short duration, calcium-dependent and suppressed by methylxanthines. Prostaglandin F alpha also inhibited TSH-induced secretion and activated iodide binding to proteins. These characteristics are similar to those of carbamylcholine action, except that prostaglandins F did not enhance cyclic GMP accumulation. The effect of prostaglandin F alpha was not inhibited by atropine, phentolamine and adenosine deaminase and can therefore not be ascribed to an induced secretion of acetylcholine, norepinephrine or adenosine. It is suggested that prostaglandins F act by increasing influx of extracellular Ca2+. Arachidonic acid also inhibited the TSH-induced cyclic AMP accumulation. However this effect was specific for TSH, it was enhanced in the absence of calcium and was not inhibited by methylxanthines or by indomethacin at concentrations which completely block its conversion to prostaglandin F alpha. Arachidonic acid action is sustained. This suggests that arachidonic acid inhibits thyroid adenylate cyclase at the level of its TSH receptor and that this effect is not mediated by prostaglandin F alpha or any other cyclooxygenase product.

摘要

前列腺素F1α和F2α在高浓度（大于或等于28微摩尔）时可增强犬甲状腺切片中环磷酸腺苷（cAMP）的积累。在较低浓度时，它们会抑制促甲状腺激素（TSH）、前列腺素E1和霍乱毒素诱导的cAMP积累。这种作用起效迅速且持续时间短，依赖于钙，并被甲基黄嘌呤所抑制。前列腺素Fα还抑制TSH诱导的分泌，并激活碘与蛋白质的结合。这些特性与氨甲酰胆碱的作用相似，只是前列腺素F不会增强环磷酸鸟苷（cGMP）的积累。前列腺素Fα的作用不受阿托品、酚妥拉明和腺苷脱氨酶的抑制，因此不能归因于乙酰胆碱、去甲肾上腺素或腺苷的诱导分泌。有人认为前列腺素F通过增加细胞外Ca2+的内流起作用。花生四烯酸也抑制TSH诱导的cAMP积累。然而，这种作用对TSH具有特异性，在无钙的情况下增强，并且不受甲基黄嘌呤或吲哚美辛的抑制，而吲哚美辛在完全阻断其转化为前列腺素Fα的浓度下仍无抑制作用。花生四烯酸的作用是持续的。这表明花生四烯酸在TSH受体水平抑制甲状腺腺苷酸环化酶，并且这种作用不是由前列腺素Fα或任何其他环氧化酶产物介导的。