Shepherd S P, Holzwarth M A
Neuroscience Program, University of Illinois, Urbana, USA.
J Neuroendocrinol. 1998 Jul;10(7):539-49. doi: 10.1046/j.1365-2826.1998.00236.x.
Phylogenetic, physiological and morphological evidence indicates that interactions between chromaffin and adrenocortical cells are involved in the differentiation and maintenance of function of both cell types. Chromaffin-adrenocortical interaction has become recognized as an important component of adrenocortical regulation; however, the mechanisms by which chromaffin cells modulate adrenocortical function are not well understood. To study directly chromaffin-adrenocortical cellular interactions, we developed primary frog (Rana pipiens) adrenal co-cultures. In these co-cultures, chromaffin cells extend processes that project towards or onto adrenocortical cells, mimicking their organization in vivo and indicating a potential for interaction between the two cell types. Cell survival and differentiation were optimized using a combination of NGF, FGF and histamine to enhance neurite outgrowth and fetal calf serum plus 10(-10) M ACTH to maintain steroidogenesis. Characterization of the cells by immunocytochemistry and histochemistry showed that chromaffin cells maintain expression of catecholamine biosynthetic enzymes and that adrenocortical cells maintain expression of steroidogenic enzymes. Furthermore, chromaffin cells release catecholamines upon stimulation with carbamylcholine or potassium while adrenocortical cells sustain a basal secretion rate of aldosterone and corticosterone that is augmented 10-40-fold by 0.1 nM to 10 nM ACTH. We therefore propose that these co-cultures serve as a useful model system to study the cellular and molecular mechanisms by which chromaffin cells modulate adrenocortical cell function.
系统发育、生理学和形态学证据表明，嗜铬细胞与肾上腺皮质细胞之间的相互作用参与了这两种细胞类型的分化和功能维持。嗜铬 - 肾上腺皮质相互作用已被认为是肾上腺皮质调节的一个重要组成部分；然而，嗜铬细胞调节肾上腺皮质功能的机制尚未完全清楚。为了直接研究嗜铬 - 肾上腺皮质细胞间的相互作用，我们建立了原代青蛙（豹蛙）肾上腺共培养体系。在这些共培养体系中，嗜铬细胞伸出突起，伸向或接触肾上腺皮质细胞，这与它们在体内的组织形式相似，表明这两种细胞类型之间存在相互作用的可能性。通过联合使用神经生长因子（NGF）、成纤维细胞生长因子（FGF）和组胺以促进神经突生长，并使用胎牛血清加10⁻¹⁰ M促肾上腺皮质激素（ACTH）来维持类固醇生成，从而优化细胞存活和分化。通过免疫细胞化学和组织化学对细胞进行表征，结果显示嗜铬细胞维持儿茶酚胺生物合成酶的表达，而肾上腺皮质细胞维持类固醇生成酶的表达。此外，嗜铬细胞在受到氨甲酰胆碱或钾刺激时释放儿茶酚胺，而肾上腺皮质细胞维持醛固酮和皮质酮的基础分泌率，0.1 nM至10 nM的ACTH可使其分泌率增加10至40倍。因此，我们认为这些共培养体系可作为一个有用的模型系统，用于研究嗜铬细胞调节肾上腺皮质细胞功能的细胞和分子机制。
