Matsui T
Department of Pharmacology, Jikei University School of Medicine, Tokyo, Japan.
Biochem Biophys Res Commun. 1991 Aug 15;178(3):1266-72. doi: 10.1016/0006-291x(91)91030-g.
We examined the effect of extracellular ATP on intracellular calcium concentration ([Ca2+]i) in bovine adrenocortical fasciculata cells. The suspended cells and the monolayer cells on coverslips were loaded with fura2. We found that ATP caused a rapid transient rise [Ca2+]i in dose-dependent manner in the presence of extracellular Ca2+ and that the rise in [Ca2+]i caused by ATP was biphasic. We did not observe the second phase in the absence of extracellular Ca2+. These results suggest that the first rise in [Ca2+]i caused by ATP is due to Ca2+ release from intracellular Ca2+ stores and subsequent rise due to Ca2+ influx across the plasma membrane. Furthermore, we found that the first phase of the monolayer cells consisted of two peaks. So it is possible that Ca2+ release from intracellular Ca2+ stores caused by ATP is induced by two different manners in adrenocortical fasciculata cells. In addition, monolayer cells are more useful than suspended ones in the examination of Ca2+ mobilization in adrenocortical fasciculata cells.
我们研究了细胞外ATP对牛肾上腺皮质束状带细胞内钙浓度（[Ca2+]i）的影响。将悬浮细胞和盖玻片上的单层细胞用fura2进行负载。我们发现，在细胞外Ca2+存在的情况下，ATP以剂量依赖性方式引起[Ca2+]i快速短暂升高，且ATP引起的[Ca2+]i升高是双相的。在没有细胞外Ca2+的情况下，我们未观察到第二相。这些结果表明，ATP引起的[Ca2+]i的首次升高是由于细胞内Ca2+储存库释放Ca2+，随后的升高是由于Ca2+跨质膜内流。此外，我们发现单层细胞的第一相由两个峰值组成。因此，在肾上腺皮质束状带细胞中，ATP引起的细胞内Ca2+储存库释放Ca2+可能是由两种不同方式诱导的。此外，在研究肾上腺皮质束状带细胞中的Ca2+动员时，单层细胞比悬浮细胞更有用。
