ALKALINE BUFFERS RELEASE EDRF FROM BOVINE CULTURED AORTIC ENDOTHELIAL-CELLS
ALKALINE BUFFERS RELEASE EDRF FROM BOVINE CULTURED AORTIC ENDOTHELIAL-CELLS
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DOI：
10.1111/j.1476-5381.1991.tb09783.x
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发表时间：
1991-06-01
影响因子：
7.3
通讯作者：
VANE, JR
中科院分区：
文献类型：
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作者：
MITCHELL, JA;DENUCCI, G;VANE, JR
1用生物测定法和放射免疫法分别测定牛主动脉内皮细胞(EC)释放内皮衍生松弛因子(EDRF)和前列环素(PGI2)。2缓激肽(BK，3~30pmol)、二磷酸腺苷(ADP，2~6nmo1)和离子载体莫能菌素(40~100nmo1)。通过EC柱注射的L-精氨酸游离碱(FB；10-20 mU-mol)或D-精氨酸FB(10-20 mU-mol)可释放类似量的EDRF，并使灌流EC的Krebs液的pH从7.5-8.0升至8.6-9.5。碳酸钠(Na2CO3)，一种碱性缓冲液，引起Krebs溶液的pH值发生相同的变化，也引起相同的EDRF释放。L或D-精氨酸盐酸盐通过EC柱注射时，既不能引起EDRF的释放，也不能增加Krebs溶液的pH。3双甘油脂肪酶(RHC 80267)或激酶(R59022)的抑制剂能抑制BK或ADP诱导的EDRF的释放，但能增强L-精氨酸FB、莫能菌素(40-100nmol)或碱性缓冲液(Na2CO3)诱导的EDRF的释放。R59022和RHC 80267可促进内皮细胞释放EDRF。4不加氯化钙时，碱性缓冲液(Na2CO3，pH 8.6-9.5)或L-精氨酸Fb(10-20mU-mol)诱导的EDRF释放与BK(3-30pmol)或腺苷二磷酸(2-6nmol)诱导的相比，被选择性地抑制。5 N(G)-单甲基L精氨酸(NMMA；30-mU-M)可抑制BK(10-30pmoL)或碱性缓冲液(Na2CO3或D-Arginine Fb；pH 8.6-9.5)诱导的EDRF释放。这种抑制作用可被L部分逆转，但不能被D-精氨酸FB或盐酸(30-100mU-M)逆转。6通过EC柱注入BK(10pmol)、ADP(2nmol)或花生四烯酸(30nmol)可释放前列环素。然而，莫能菌素(40nmol)或碱性缓冲液(pH 8.6-9.5)不能释放可检测到的6-氧-前列腺素F1-α前列腺素I2。7因此，外部浴液的碱化可以通过一种不涉及受体激活的机制从培养的EC释放EDRF，该机制依赖于细胞外钙的存在。
1 Release of endothelium-derived relaxing factor (EDRF) and prostacyclin (PGI2) from bovine cultured aortic endothelial cells (EC) was measured by bioassay and radioimmunoassay, respectively.2 Bradykinin (BK, 3-30 pmol), adenosine diphosphate (ADP, 2-6 nmol) or the sodium ionophore monensin (40-100 nmol) injected through a column of EC released EDRF. L-Arginine free base (FB; 10-20-mu-mol) or D-arginine FB (10-20-mu-mol) injected through the column of EC released similar amounts of EDRF and also caused an increase in pH of the Krebs solution perfusing the EC from 7.5-8.0 to 8.6-9.5. Sodium carbonate (Na2CO3) an alkaline buffer which caused the same changes in the pH of the Krebs solution also induced the same release of EDRF. The hydrochloride salts of L- or D-arginine did not cause either release of EDRF when injected through the column of EC or increases in the pH of the Krebs solution.3 Inhibitors of either diacylglycerol lipase (RHC 80267) or kinase (R59022) inhibited the release of EDRF induced by BK or ADP but potentiated the release induced by L-arginine FB, monensin (40-100 nmol) or alkaline buffer (Na2CO3). R59022 and RHC 80267 infused through the EC increased the basal release of EDRF.4 When calcium chloride was omitted from the Krebs solution the release of EDRF induced by alkaline buffer (Na2CO3; pH 8.6-9.5) or L-arginine FB (10-20-mu-mol) was selectively inhibited when compared to that induced by BK (3-30 pmol) or ADP (2-6 nmol). This inhibition was reversed when calcium (2.5 mM) was restored.5 N(G)-monomethyl-L-arginine (NMMA; 30-mu-M) inhibited release of EDRF induced by BK (10-30 pmol) or alkaline buffers (Na2CO3 or D-arginine FB; pH 8.6-9.5). This inhibition was partially reversed by L- but not D-arginine FB or HCl (30-100-mu-M).6 Prostacyclin was released when BK (10 pmol), ADP (2 nmol) or arachidonic acid (30 nmol) were injected through the column of EC. However, monensin (40 nmol) or alkaline buffers (pH 8.6-9.5) did not release detectable amounts of PGI2 as measured by radioimmunoassay for 6-oxo-prostaglandin F1-alpha.7 Thus alkalinisation of the external bathing solution can release EDRF from cultured EC by a mechanism which does not involve receptor activation and which depends on the presence of extracellular calcium.