虫草素对大鼠垂体细胞促肾上腺皮质激素释放因子刺激及类固醇对促肾上腺皮质激素分泌抑制作用的影响。

Effect of cordycepin on CRF stimulation and steroid inhibition of ACTH secretion by rat pituitary cells.

作者信息

Brattin W J, Portanova R

出版信息

Mol Cell Endocrinol. 1978 Jan;9(3):279-89. doi: 10.1016/0303-7207(78)90070-9.

PMID:203501

Abstract

Isolated pituitary cells prepared from adrenalectomized rats secrete ACTH in response to CRF, and this response is inhibited by corticosterone. Both the stimulation of release by CRF and the inhibition of release by corticosterone are antagonized by cordycepin (3'-deoxyadenosine). Inhibition of CRF-stimulated secretion by cordycepin is apparently not related to inhibition of RNA synthesis, since high doses of actinomycin D do not affect ACTH secretion. More likely, cordycepin's inhibition of secretion stems from its inhibition of adenylate cyclase activity. Inhibition of corticosterone action by cordycepin is qualitatively similar to that previously reported actinomycin D. This effect of both drugs is probably due to inhibition of RNA synthesis. Significantly, a low dose of cordycepin has a greater inhibitory effect on corticosterone action than on total cellular RNA synthesis. Cordycepin is reported to preferentially inhibit messenger RNA synthesis, and low dose preferentially inhibits appearance of cytoplasmic RNA in pituitary cells. These data suggest that corticosterone-induced RNA is a cytoplasmic (messenger) RNA.

摘要

从肾上腺切除的大鼠制备的垂体细胞在促肾上腺皮质激素释放因子（CRF）作用下分泌促肾上腺皮质激素（ACTH），而这种反应会被皮质酮抑制。CRF对释放的刺激以及皮质酮对释放的抑制均被虫草素（3'-脱氧腺苷）拮抗。虫草素对CRF刺激分泌的抑制显然与RNA合成的抑制无关，因为高剂量放线菌素D并不影响ACTH分泌。更有可能的是，虫草素对分泌的抑制源于其对腺苷酸环化酶活性的抑制。虫草素对皮质酮作用的抑制在性质上与先前报道的放线菌素D相似。这两种药物的这种作用可能是由于RNA合成的抑制。值得注意的是，低剂量虫草素对皮质酮作用的抑制比对总细胞RNA合成的抑制作用更大。据报道，虫草素优先抑制信使RNA合成，低剂量优先抑制垂体细胞中细胞质RNA的出现。这些数据表明，皮质酮诱导的RNA是一种细胞质（信使）RNA。