Glucose-induced changes in protein kinase C and nitric oxide are prevented by vitamin E
Glucose-induced changes in protein kinase C and nitric oxide are prevented by vitamin E
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DOI：
10.1152/ajpendo.2000.278.1.e146
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发表时间：
2000-01-01
影响因子：
5.1
通讯作者：
Seftel, A
中科院分区：
文献类型：
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作者：
Ganz, MB;Seftel, A
蛋白激酶C(PKC)、活性氧产物和一氧化氮(NO)活性或表达的变化可能是糖尿病细胞行为改变的原因。这些变化被认为是勃起功能障碍的病理生理学的一部分。我们试图确定在高糖环境中生长的海绵体血管平滑肌细胞(CCSMC)是否表现出PKC亚型、NO和活性氧产物的活性和表达的变化，以及α-生育酚是否能阻止这些变化。大鼠CCSMC在5、15和30 mM的葡萄糖浓度中培养3、7和14天。用异构体特异性抗体检测PKC亚型的表达。在30 mM葡萄糖中培养2周的CCSMCs，PKC-β(2)-亚型表达上调(n=4；P<；0.01)，而α、β-、β-和β(1)-亚型的表达没有变化。与5 mM的葡萄糖相比，30 mM(n=4；P<；0.002)的NO在14天时以硝酸盐/亚硝酸盐的比率显著降低。用二氯二乙酸二氯荧光素双(乙酰氧甲基)(DCFH-DA)(n=5；P<；0.01)荧光探针检测14天后活性氧产物表达上调(P<0.01)。当这些细胞暴露于α-生育酚14天时，PKC-β(2)减少(57.8%；P<；0.01；n=4)，活性氧生成减少(71.1%；P<；0.001；n=4)，硝酸盐/亚硝酸盐比率(43.9%；P<；0.01，n=4)增加。这些结果提示，高糖环境下CCSMC中PKC、NO与活性氧产物的形成之间可能存在相互关系。
Changes in activity or expression of protein kinase C (PKC), reactive oxygen products, and nitric oxide (NO) may account for the alteration in cell behavior seen in diabetes. These changes have been proposed to be part of the pathophysiology of erectile dysfunction. We sought to ascertain if corpus cavernosal vascular smooth muscle cells (CCSMC) grown in a high glucose milieu exhibit changes in the activity and expression of PKC isoforms, NO, and reactive oxygen products and to find out if these changes are prevented by alpha-tocopherol. Rat CCSMC were grown in 5, 15, and 30 mM glucose concentrations for 3, 7, and 14 days. PKC isoform expression was assayed with isoform-specific antibodies. In CCSMCs grown in 30 mM glucose for 2-wk, PKC-beta(2)-isoform was upregulated (n = 4; P < 0.01), whereas the expression of alpha-, delta-, epsilon-, and beta(1)-isoforms was unchanged. NO as measured by nitrate-to-nitrite ratio was greatly diminished at 14 days in 30 mM (n = 4; P < 0.002) compared with 5 mM glucose. Reactive oxygen products were upregulated at 14 days when they were assayed by the fluorescent probe dichlorofluorescein diacetate bis(acetoxy-methyl) (DCFH-DA) (n = 5; P < 0.01). When these same cells were exposed to alpha-tocopherol for 14 days, there was a reduction of PKC-beta(2) (57.8%; P < 0.01; n = 4) and a reduction in reactive oxygen product formation (71.1%; P < 0.001; n = 4), along with an increase in nitrate-to-nitrite ratio (43.9%; P < 0.01, n = 4). These results suggest that there may be an interrelationship between PKC, NO, and reactive oxygen product formation in CCSMC exposed to a high glucose environment.