Greenberg A, Zinder O
Cell Tissue Res. 1982;226(3):655-65. doi: 10.1007/BF00214792.
The regulation of secretion of catecholamines from bovine adrenal medulla cells was investigated by use of an improved and highly efficient method for isolating viable and responsive cells from this tissue. The method involves an in situ collagenase perfusion affecting only the connective tissue matrix of the medulla while leaving the cortex intact. The cells released both epinephrine and norepinephrine in response to stimulation by 100 microM acetylcholine. The ratio of epinephrine to norepinephrine in the medium following non-stimulated (basal) release, was similar to that found in the intact cells. On the other hand, a lower ratio of epinephrine to norepinephrine was found in the medium following stimulation by acetylcholine due mainly to preferential secretion of norepinephrine. This release ceased after 15 min of incubation and consisted of 15--20% of the catecholamines initially present in the cells. Exogenous epinephrine was found to inhibit total catecholamine secretion; however, it stimulated norepinephrine release. Addition of isoproterenol caused a stimulation of release while propranolol was inhibitory. Norepinephrine inhibited total release not favoring any specific catechol. Other alpha-agonists, such as clonidine, also had an inhibitory effect. These results suggest a receptor-mediated mechanism for the fine regulation of secretion from the adrenal medulla.
利用一种改进的高效方法从牛肾上腺髓质组织中分离出有活力且有反应的细胞，对儿茶酚胺从牛肾上腺髓质细胞的分泌调节进行了研究。该方法包括原位胶原酶灌注，此过程仅影响髓质的结缔组织基质，而使皮质保持完整。细胞在受到100微摩尔乙酰胆碱刺激时会释放肾上腺素和去甲肾上腺素。非刺激（基础）释放后培养基中肾上腺素与去甲肾上腺素的比例，与完整细胞中的比例相似。另一方面，乙酰胆碱刺激后培养基中肾上腺素与去甲肾上腺素的比例较低，这主要是由于去甲肾上腺素的优先分泌。这种释放在孵育15分钟后停止，且占细胞中最初存在的儿茶酚胺的15% - 20%。发现外源性肾上腺素会抑制儿茶酚胺的总分泌；然而，它会刺激去甲肾上腺素的释放。加入异丙肾上腺素会导致释放增加，而普萘洛尔则具有抑制作用。去甲肾上腺素抑制总释放，对任何特定儿茶酚无偏好。其他α - 激动剂，如可乐定，也有抑制作用。这些结果表明存在一种受体介导的机制，用于对肾上腺髓质的分泌进行精细调节。
