Ohata H, Seito N, Aizawa H, Nobe K, Momose K
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Biochem Biophys Res Commun. 1995 Mar 8;208(1):19-25. doi: 10.1006/bbrc.1995.1299.
We found that lysophosphatidic acid (LPA) sensitizes response in cytosolic free Ca2+ concentration ([Ca2+]i) to mechanical stimulation in cultured longitudinal muscle cells from guinea pig ileum. [Ca2+]i was transiently increased by spritzing of bath solution onto cells as mechanical stimulation in the presence of LPA, but not in absence of LPA. The effect was reversible and concentration-dependent (1-30 nM). Ga3+ but not nicardipine inhibited the [Ca2+]i transient in the presence of LPA. Phosphatidic acid also induced the sensitization, but the effective concentration was more than 10 times higher than in LPA. Histamine and carbachol did not have any sensitizing effect to mechanical stimulation. These results show that LPA sensitizes mechanoreceptor-linked response, suggesting that LPA may play an important role in mechanotransduction mechanisms as an endogenous regulatory factor.
我们发现，溶血磷脂酸（LPA）可使豚鼠回肠培养的纵行肌细胞中细胞溶质游离钙离子浓度（[Ca2+]i）对机械刺激的反应敏感化。在存在LPA的情况下，作为机械刺激，通过向细胞喷洒浴液可使[Ca2+]i短暂升高，但在不存在LPA时则不会。该效应是可逆的且呈浓度依赖性（1 - 30 nM）。在存在LPA的情况下，Ga3+而非尼卡地平可抑制[Ca2+]i瞬变。磷脂酸也可诱导敏感化，但有效浓度比LPA高10倍以上。组胺和卡巴胆碱对机械刺激没有任何敏感化作用。这些结果表明，LPA使机械感受器相关反应敏感化，提示LPA可能作为一种内源性调节因子在机械转导机制中发挥重要作用。
