Wegner J A, Martinez-Zaguilan R, Gillies R J, Hoyer P B
Department of Physiology, Arizona Health Sciences Center, University of Arizona, Tucson 85724.
Am J Physiol. 1994 Jan;266(1 Pt 1):E50-6. doi: 10.1152/ajpendo.1994.266.1.E50.
Thapsigargin (TG) and A23187 were used to examine the regulation of cytosolic free calcium (Cai2+) in ovine large and small luteal cells. Thapsigargin (50 nM) induced a sustained increase of Cai2+ in fura 2-acetoxymethyl ester (AM)-loaded cells (large = 1.32 +/- 0.07-fold, small = 1.45 +/- 0.07-fold, P < 0.05). A23187 (1 microM) induced a rapid transient increase of Cai2+ (large = 1.37 +/- 0.07-fold, small = 1.46 +/- 0.10-fold, P < 0.05). In large cells, 0.5 microM prostaglandin F2 alpha (PGF2 alpha) increased Cai2+ 1.54 +/- 0.11-fold. Pretreatment with 50 nM TG abolished the PGF2 alpha-induced calcium response. Pretreatment with PGF2 alpha attenuated (P < 0.05) the TG-induced Cai2+ increase. Progesterone secretion was significantly (P < 0.05) inhibited by incubation with 50 nM TG, 1 microM A23187, and 0.5 microM PGF2 alpha in large but not small cells. These data suggest that PGF2 alpha releases calcium from a TG-sensitive intracellular calcium pool in ovine large luteal cells.
毒胡萝卜素（TG）和A23187用于检测绵羊大、小黄体细胞中胞质游离钙（Cai2+）的调节情况。毒胡萝卜素（50 nM）可使负载fura 2 - 乙酰氧基甲酯（AM）的细胞中Cai2+持续升高（大细胞 = 1.32 ± 0.07倍，小细胞 = 1.45 ± 0.07倍，P < 0.05）。A23187（1 μM）可使Cai2+快速短暂升高（大细胞 = 1.37 ± 0.07倍，小细胞 = 1.46 ± 0.10倍，P < 0.05）。在大细胞中，0.5 μM前列腺素F2α（PGF2α）可使Cai2+升高1.54 ± 0.11倍。用50 nM TG预处理可消除PGF2α诱导的钙反应。用PGF2α预处理可减弱（P < 0.05）TG诱导的Cai2+升高。在大细胞而非小细胞中，50 nM TG、1 μM A23187和0.5 μM PGF2α孵育可显著（P < 0.05）抑制孕酮分泌。这些数据表明，PGF2α可从绵羊大黄体细胞中对TG敏感的细胞内钙库释放钙。
