ABSTRACT
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Humans , Drug Interactions/physiology , Antihypertensive Agents , Pharmacy Service, Hospital/trendsABSTRACT
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Subject(s)
Humans , Drug Interactions , Drug Incompatibility , Adverse Drug Reaction Reporting Systems , Medication Systems, Hospital/trendsABSTRACT
BACKGROUND: Oxidative stress is considered to play a role in the pathogenesis of diabetic nephropathy. Angiotensin-converting enzyme (ACE) inhibitors are hypotensive drugs with a well-known effect in preventing the progression of chronic renal failure. Their mechanism of action is not clearly established. METHODS: The effect of enalaprilat on hydrogen peroxide (H2O2) production by cultured murine mesangial cells exposed to 5.5 (basal condition), 30 and 50 mM glucose concentrations was examined over 8 h. A fluorimetric method quantifying, in arbitrary units, the intracellular dichlorofluorescein (DCFH) oxidation to the highly fluorescent compound 2'7'dichlorofluorescein (DCF) from the non-fluorescent probe dichlorofluorescein-diacetate (DCFH-DA) was employed (a method not previously reported for cultured mesangial cells). Experiments were repeated three times in quadruplicate wells. RESULTS: H2O2 production by mesangial cells exposed to 50 mM glucose was significantly increased after 1 h, compared to cells exposed to 5.5 and 30 mM glucose. This observation was not reproduced with 50 mM mannitol. Addition of 100 ng/ml enalaprilat to cells with 50 mM glucose significantly inhibited H2O2 production during the 8 h of the assay. This response was similar to that obtained with 100 ng/ml catalase. Increasing enalaprilat concentrations (10, 50 and 100 ng/ml) also significantly decreased the constitutive H2O2 generation in the presence of 5.5 mM glucose. Angiotensin II and saralasin, both at 1 microM, did not modify H2O2 production by cells exposed to 5.5 mM glucose. In contrast, 1 microM staurosporine, a protein kinase C (PKC) antagonist, significantly decreased H2O2 generation in the presence of 50 mM glucose. CONCLUSION: Enalaprilat has an antioxidant effect in cultured mesangial cells. This action is not linked to ACE inhibition, but may be related to an inhibition of the PKC system.
