Andreis P G, Neri G, Mazzocchi G, Musajo F, Nussdorfer G G
Department of Anatomy, University of Padua, Italy.
Endocrinology. 1992 Jul;131(1):69-72. doi: 10.1210/endo.131.1.1319330.
CRF dose-dependently enhanced corticosterone (B) secretion by rat adrenal slices including both cortex and medulla. Conversely, CRF did not exert any B response by fragments of adrenocortical autotransplants, which are completely deprived of chromaffin tissue. However, autotransplant quarters exhibited a dose-dependent response to ACTH qualitatively similar to that of adrenal slices, although markedly less intense. The maximal B response of adrenal slices to CRF (10(-8) M) was completely annulled by corticotropin-inhibiting peptide (10(-6) M), a competitive inhibitor of ACTH, which totally blocked the secretory response to ACTH (10(-8) M) of both kinds of preparations. ACTH immunoreactivity was present in the adrenal gland of control rats, but was undetectable in autotransplanted adrenocortical nodules. Moreover, adrenal fragments mainly composed of chromaffin tissue released detectable amounts of ACTH in response to high concentrations of CRF (10(-8)/10(-6) M). These findings suggest that chromaffin medullary cells play a pivotal role in the direct adrenocortical secretagogue effect of CRF, probably by releasing ACTH, which, in turn, may evoke, in a paracrine manner, the glucocorticoid response.
促肾上腺皮质激素释放因子（CRF）能剂量依赖性地增强包含皮质和髓质的大鼠肾上腺切片的皮质酮（B）分泌。相反，CRF对完全去除嗜铬组织的肾上腺皮质自体移植碎片未产生任何B反应。然而，自体移植的四分之一组织对促肾上腺皮质激素（ACTH）呈现出与肾上腺切片在性质上相似的剂量依赖性反应，尽管强度明显较低。肾上腺切片对CRF（10^(-8) M）的最大B反应被促肾上腺皮质激素抑制肽（10^(-6) M）完全消除，促肾上腺皮质激素抑制肽是ACTH的竞争性抑制剂，它完全阻断了两种制剂对ACTH（10^(-8) M）的分泌反应。ACTH免疫反应性存在于对照大鼠的肾上腺中，但在自体移植的肾上腺皮质结节中无法检测到。此外，主要由嗜铬组织组成的肾上腺碎片在高浓度CRF（10^(-8)/10^(-6) M）作用下释放出可检测量的ACTH。这些发现表明，嗜铬髓质细胞在CRF的直接肾上腺皮质促分泌作用中起关键作用，可能是通过释放ACTH，而ACTH反过来可能以旁分泌方式引发糖皮质激素反应。
