Endothelin-1 stimulates prostaglandin E2 production in an extracellular calcium-independent manner in cultured rat mesangial cells.
Endothelin-1 stimulates prostaglandin E2 production in an extracellular calcium-independent manner in cultured rat mesangial cells.
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在培养的大鼠系膜细胞中，Endothelin-1 以不依赖细胞外钙的方式刺激前列腺素 E2 的产生。
DOI：
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发表时间：
1991
影响因子：
3.2
通讯作者：
T. Kamada
中科院分区：
文献类型：
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作者：
M. Fukunaga;S. Ochi;T. Takama;K. Yokoyama;Y. Fujiwara;Y. Orita;T. Kamada
为了研究内皮素-1 （ET-1）在调节肾小球功能中的可能作用，我们在培养的大鼠系膜(M)细胞中检测了ET-1受体的存在及其生物学作用。采用Sprague-Dawley大鼠离体肾小球首次传代培养的M细胞。用125I-ET-1检测ET-1的结合。采用IP3特异性结合法测定肌醇1,4,5-三磷酸（IP3）含量。在fura-2负载细胞中测量细胞内钙（iCa2+）。放射免疫法测定前列腺素E2 （PGE2）水平。在M细胞中存在两类ET-1特异性结合位点（Kd分别为0.24和4.4 nmol/L， Bmax分别为130和1070 fmol/mg）。ET-1 （10(-7) mol/L）诱导IP3快速、短暂升高，随后iCa2+短暂、持续升高。尼卡地平（10(-6)mol/L）仅抑制iCa2+的持续升高。ET-1 (10（-9) mol/L ~ 10(-7) mol/L）显著刺激PGE2生成，且具有浓度依赖性。尼卡地平（10(-6)mol/L）和地尔硫卓（10(-6)mol/L）对PGE2的产生没有抑制作用。我们得出结论，M细胞具有特异性的ET-1受体，与磷酸肌苷的转化和PGE2的产生有关，ET-1产生PGE2可能是通过细胞外钙独立机制。我们的研究结果表明ET-1通过调节M细胞中PGE2的产生在肾小球功能的调节中起重要作用。
To study a possible role of endothelin-1 (ET-1) in the regulation of glomerular function, we examined the presence of receptors for, and the biological action of, ET-1 in cultured rat mesangial (M) cells. The first-subcultured M cells prepared from isolated glomeruli of Sprague-Dawley rats were used. ET-1 binding was assayed by using 125I-ET-1. Inositol 1,4,5-trisphosphate (IP3) was determined by IP3-specific binding assay. Intracellular calcium (iCa2+) was measured in fura-2 loaded cells. Prostaglandin E2 (PGE2) was measured by radioimmunoassay. In M cells there existed two classes of binding sites specific for ET-1 (Kd was 0.24 and 4.4 nmol/L, Bmax was 130 and 1070 fmol/mg, respectively). ET-1 (10(-7) mol/L) induced a rapid and transient increase in IP3, followed by transient and sustained increases in iCa2+. Nicardipine (10(-6) mol/L) inhibited only the sustained increase in iCa2+. ET-1 (10(-9) mol/L to 10(-7) mol/L) significantly stimulated PGE2 production with the concentration dependency. Nicardipine (10(-6) mol/L) and diltiazem (10(-6) mol/L) did not inhibit the PGE2 production. We conclude that M cells have specific ET-1 receptors linked to phosphoinositide turnover and PGE2 production, and PGE2 production by ET-1 may be through an extra-cellular calcium-independent mechanism. Our results suggest that ET-1 plays an important role in the regulation of glomerular functions by modulating PGE2 production in M cells.