The binding of the dihydropyridine calcium channel antagonist [3H]nitrendipine to whole rat brain synaptosomes was studied. Binding was specific, saturable, and of high affinity (Kd = 170 pM). The calcium channel antagonist diltiazem enhanced [3H]nitrendipine binding in synaptosomes in concentrations of 1 and 10 μM. Equilibrium saturation analysis demonstrated that this effect was mediated by a decrease in the dissociation constant, due to a 3-fold reduction in the rate of ligand-receptor complex dissociation. It is concluded that diltiazem allosterically modulates the calcium channel drug receptor labeled by [3H]nitrendipine in this preparation.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Sep 30 1982|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology