GSH : Electrochemical assessment of adduct formation with nimodipine and propranolol

¹ Laboratory ot Pharmacology, Faculty of Chemical and Pharmaceutical Sciences;, Chilie.
² Laboratory of Electrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Po Box 233, Santiago, Chile.

Abstract

The present paper demonstrates through voltammetric methods and UV spectroscopy the feasibility of the in vitro adduct formation Glutathione-Nimodipine and Glutathione- Propranolol in absence of enzymatic catalysis. The effect of pH, temperature and reaction media on the adduct formation is assessed. Under physiological canditions (pH 7.4, 37°C) the apparent affinity constants were: Kapp GSH-NMD= 1.21-10⁶ M_-1; Kapp GSH-PRP=7.64-10³ M^_1 and a 1:1 molar ratio for both interactions were found. Thermodynamic data indicate that the adduct formations were spontaneous.

Résumé

En utilisant des techniques et spectroscopiques (U.V.) on montre la formation in vitro de complexes 1:1 entre le glutathion, la nimodipine et le propranolol, dans des conditions physiologiques (pH = 7,4, 37°C) et en absence de catalyse enzymatique. Les caractéristiques thermodynamiques (H, G, S) des complexes 1:1 ont été évaluées, entre autres les constantes apparentes d'affinité : Kapp GSH-NMD = 1.21-10⁶ M^_1 Kapp GSH-RPR = 7.64-10³ M^-1