摘要：
We studied 14 moderately overweight Type 2 diabetic patients with essential hypertension in stable metabolic control after a run-in period, and again after 3 months of antihypertensive treatment with the angiotensin-converting enzyme (ACE) inhibitor captopril. Glucose tolerance was tested with a 75g oral glucose load (OGTT) and insulin sensitivity was measured by the insulin suppression test (IST) while dietary and drug treatment of the hyperglycemia was maintained constant. In the whole group, mean blood pressure (MBP) fell progressively over 3 months from a baseline value of 123 +/- 3 mmHg (1 mmHg = 0.133 kpa) to a final value of 115 +/- 2 mmHg (P < 0.005). After treatment, fasting plasma glucose, insulin, free fatty acid (FFA), potassium, and glycosylated hemoglobin concentrations were unchanged from baseline. There were no significant differences in glucose tolerance and insulin sensitivity between pre- and post-treatment values. Neither endogenous (oral glucose) nor exogenous (IST) insulin caused any change in plasma potassium concentration. This resistance to the hypokalemic action of insulin was not affected by captopril.
作者机构：
[CHEN, X; LIAO, DF] HUNAN MED UNIV,DEPT PHARMACOL,CHANGSHA 410078,PEOPLES R CHINA.;[LIAO, DF] HENGYANG MED COLL,DEPT PHARMACOL,HENGYANG 421001,PEOPLES R CHINA.
通讯机构：
[LIAO, DF] H;HENGYANG MED COLL,DEPT PHARMACOL,HENGYANG 421001,PEOPLES R CHINA.
摘要：
We report here the protective effect of the angiotensin converting enzyme inhibitors captopril and ramiprilat against damage due to oxygen free radicals on aortic endothelium in a superfusion cascade system. Oxygen free radicals were generated by electrolysis of Krebs solution. Acetylcholine was infused through the donor aortic segment and relaxation of the detector aortic ring was used to indicate the release of endothelium-derived relaxing factor (EDRF). The percentage of relaxation before and after electrolysis was compared to calculate the relaxation index. Electrolyzed Krebs solution impaired the release of EDRF, as shown by a reduction in the relaxation index with a concomitant decrease in the tissue levels of superoxide dismutase and 6-keto PGF1 alpha and increase in malondialdehyde in the donor vessel. Captopril (100 microM), 15 microM ramiprilat and 30 nM iloprost had a protective effect as shown by a significantly smaller reduction in the relaxation index and the level of 6-keto PGF1 alpha and by an attenuation of the production of malondialdehyde. In addition, 1 microM indomethacin almost eliminated the protection by captopril. We conclude that both the SH-containing angiotensin-converting enzyme inhibitor captopril and the non-SH-containing ramiprilat, as well as iloprost, a stable analog of prostacyclin, can protect rabbit aortic endothelium against damage due to oxygen free radicals. The mechanism of such protection may be partly associated with the facilitation of the release of prostacyclin and consequent reduction in lipid peroxidation.
