Douglas Shirley A, Stevenson Kate E, Knowles Penelope J, Bunn Stephen J
Department of Anatomy and Structural Biology, The University of Otago, P.O. Box 913, Dunedin, New Zealand.
Neurosci Lett. 2008 Nov 7;445(1):126-9. doi: 10.1016/j.neulet.2008.08.060. Epub 2008 Aug 28.
Isolated adrenal medullary chromaffin cells maintained in culture have been widely used to study neurosecretory events. Many of these studies have been conducted using cells obtained from the bovine adrenal. In this study we have cultured chromaffin cells from an alternative large animal model, the deer, and have conducted the first characterization of secretion from this preparation. Cervine chromaffin cells, preloaded with [3H]noradrenalin, displayed a strong secretory response to the cholinergic agonist carbachol, with a maximal secretion of approximately 28% cell content over 15 min. This response was reproduced by nicotinic but not muscarinic agonists and was similarly inhibited by nicotinic but not muscarinic antagonists. Nicotine-evoked secretion measured over a 15 min time period was inhibited approximately 50% by the L-type Ca2+-channel antagonist nifedipine and approximately 20% by N-type (omega-conotoxin GVIA) or N, P/Q-type (omega-conotoxin MVIIC) antagonists. In contrast the response was unaffected by omega-agatoxin IVA, a P/Q-type antagonist. In addition to nicotinic receptor stimulation, activation of PACAP or histamine H1 receptors resulted in a concentration-dependent increase in secretion. PACAP was approximately two-fold more effective than histamine although both were weaker secretagogues than nicotine. In contrast, cervine chromaffin cells did not respond to angiotensin II or bradykinin, two agents known to stimulate secretion from bovine chromaffin cells. These data provide an initial characterization of the secretory response from cervine adrenal medullary chromaffin cells indicating that there are marked similarities but also potentially significant differences between them and their far more extensively described bovine counterparts.
培养的分离肾上腺髓质嗜铬细胞已被广泛用于研究神经分泌事件。许多此类研究是使用从牛肾上腺获得的细胞进行的。在本研究中，我们培养了来自另一种大型动物模型——鹿的嗜铬细胞，并首次对该制剂的分泌进行了表征。预先加载[3H]去甲肾上腺素的鹿嗜铬细胞对胆碱能激动剂卡巴胆碱表现出强烈的分泌反应，在15分钟内最大分泌量约为细胞内容物的28%。这种反应由烟碱型而非毒蕈碱型激动剂重现，并且同样被烟碱型而非毒蕈碱型拮抗剂抑制。在15分钟时间段内测量的尼古丁诱发的分泌被L型钙通道拮抗剂硝苯地平抑制约50%，被N型（ω-芋螺毒素GVIA）或N、P/Q型（ω-芋螺毒素MVIIC）拮抗剂抑制约20%。相比之下，该反应不受P/Q型拮抗剂ω-蛛毒素IVA的影响。除了烟碱受体刺激外，PACAP或组胺H1受体的激活导致分泌浓度依赖性增加。PACAP的效力约为组胺的两倍，尽管两者都是比尼古丁弱的促分泌剂。相比之下，鹿嗜铬细胞对已知能刺激牛嗜铬细胞分泌的血管紧张素II或缓激肽没有反应。这些数据提供了鹿肾上腺髓质嗜铬细胞分泌反应的初步表征，表明它们与描述更为广泛的牛对应细胞之间存在明显的相似之处，但也可能存在显著差异。
