Role of Ca2+ and cyclic AMP in the regulation of the production of prostacyclin by the vascular endothelium.
Role of Ca2+ and cyclic AMP in the regulation of the production of prostacyclin by the vascular endothelium.
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DOI：
10.1073/pnas.79.2.495
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发表时间：
1982
影响因子：
11.1
通讯作者：
A. Brotherton;J. Hoak
中科院分区：
文献类型：
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作者：
A. Brotherton;J. Hoak
用缓冲液、凝血酶（0.5单位/ml）、离子载体A23187（10微米）、花生四烯酸（20微米）、前列腺素H2 (PGH2)（4微米）培养人脐静脉内皮细胞，通过6-酮- pgf α的放射免疫测定，产生纳摩尔量的前列腺环素（PGI2）分别为36 +/- 2、276 +/- 13、485 +/- 32、533 +/- 22和532 +/- 22。内皮预孵养1 mM 8-（N，N-二乙基氨基）-辛基-3,4,5-三甲氧基苯甲酸酯（细胞质Ca2+拮抗剂）或4 mM 1-甲基-3-异丁基黄嘌呤（环核苷酸磷酸二酯酶活性抑制剂），阻断凝血酶或A23187诱导的PGI2释放，减少花生四烯酸诱导的释放约50%，但对pgh2诱导的释放没有影响。内皮细胞cAMP放射免疫分析显示，4 mM MIX平均增加3.9倍的基础水平（每4.5 × 10(5)个细胞1.85 +/- 0.14 pmol cAMP）。在没有MIX的情况下，PGI2（0.4微米）对cAMP水平没有显著影响，但在4毫米MIX的情况下，cAMP水平增加了2倍。研究结果表明：(i) PGI2生物合成的刺激是由Ca2+介导的，（ii）增加的cAMP抑制PGI2的产生，（iii） cAMP磷酸二酯酶活性调节PGI2诱导的细胞内cAMP浓度的增加。
Incubation of primary monolayer cultures of human umbilical vein endothelial cells with buffer, thrombin (0.5 unit/ml), ionophore A23187 (10 microM), arachidonic acid (20 microM), prostaglandin H2 (PGH2) (4 microM) resulted in prostacyclin (PGI2) production in nanomolar quantities to the extent of 36 +/- 2, 276 +/- 13, 485 +/- 32, 533 +/- 22, and 532 +/- 22, respectively, as measured by radioimmunoassay of 6-keto-PGF alpha. Preincubation of the endothelium with 1 mM 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate, an antagonist of cytoplasmic Ca2+, or with 4 mM 1-methyl-3-isobutylxanthine (MIX), an inhibitor of cyclic nucleotide phosphodiesterase activity, blocked PGI2 release induced by thrombin or A23187, decreased arachidonic acid-induced release by approximately 50%, but had no effect on PGH2-induced release. Radioimmunoassay of cAMP in the endothelium showed that the basal level (1.85 +/- 0.14 pmol of cAMP per 4.5 x 10(5) cells) was increased by an average of 3.9-fold with 4 mM MIX. PGI2 (0.4 microM) had no significant effect on cAMP levels in the absence of MIX, but caused a 2-fold increase with 4 mM MIX. The findings suggest that: (i) the stimulation of PGI2 biosynthesis is mediated by Ca2+, (ii) increased cAMP inhibits PGI2 production, and (iii) cAMP phosphodiesterase activity modulates PGI2-induced increases in the intracellular concentration of cAMP.