Interactions between calcium entry blocking drugs and carbonic anhydrase.

The interactions between some of the most common calcium entry blocker drugs (CEB) and the enzyme carbonic anhydrase (CA) are studied in the present work by an electroanalytical approach. The study comprises drugs belonging to the classes of phenylalkylamines, dihydropyridines, benzothiazepines and piperazines. The evaluation of the potential inhibitory power towards CA was performed either by measuring the speed of CO2 diffusion taking place from a buffered solution of NaHCO3, or by monitoring the metabolic activity of yeast cells. The results obtained according to both of these procedures have shown that verapamil and gallopamil are endowed with a relevant inhibitory power on CA catalytic activity, whereas all the other compounds, tested in the same experimental conditions, did not show any effect on CA activity.