Evidence for down-regulation of 3H-nitrendipine recognition sites in mouse brain after long-term treatment with nifedipine or verapamil.

Mice were fed powdered food which contained nifedipine, verapamil or diltiazem for 28 days. Long lasting treatment with nifedipine (0.28 mg/g b.w./day) or verapamil (0.27 mg/g b.w./day), but not with diltiazem (0.38 mg/g b.w./day) reduced the number of 3H-nitrendipine recognition sites in membranes prepared from cerebral cortex, caudate nucleus, and hippocampus. In addition, the veratridine-elicited stimulation of 45Ca-uptake in slices of the same brain areas was decreased in mice which were fed nifedipine or verapamil for 28 days.