Effects of menidipine on dihydropyridines binding sites in cardiac and cerebral membranes from old rats with left ventricular hypertrophy.
OBJECTIVE
To study the effects of menidipine (Men) on the affinity and density of dihydropyridines (DHP) binding sites in the cell membranes of left ventricle (LV) and brain in elderly renovascular hypertensive rats (RVHR) with LV hypertrophy.


METHODS
Renovascular hypertension was produced by clipping the left renal artery in 20-month-old rats. The affinity and density of DHP binding sites in the cell membranes of LV and brain were assessed by radioligand assay.


RESULTS
Men (20 mg.kg-1.d-1 ig for 9 wk) decreased markedly the systolic blood pressure and the LV weight (P < 0.01). Though not affecting the density of DHP receptor (Bmax), Men markedly decreased the total number of DHP binding sites in hypertrophied LV (from 5.95 +/- 0.62 to 4.0 +/- 1.1 pmol.LV). Men also reduced Bmax of DHP binding sites in the thalamus (from 522 +/- 27 to 371 +/- 24 pmol/g protein) and hippocampus (from 498 +/- 26 to 332 +/- 32 pmol/g protein).


CONCLUSIONS
Men reversed the LV hypertrophy from renovascular hypertension accompanied with reduced total number of DHP binding sites in the cell membranes of LV and Bmax of the cell membranes of thalamus and hippocampus from elderly LV hypertrophied rats.
Xi
T
T
Department of Cardiovascular Pharmacology, Nanjing Medical University, China.
Rao
M R
MR
D000818:Animals; D001921:Brain / Q000473:pathology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism*; D020746:Calcium Channels, L-Type; D002462:Cell Membrane / Q000378:metabolism; D006978:Hypertension, Renovascular / Q000150:complications / Q000378:metabolism*; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000473:pathology; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011869:Radioligand Assay; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; C116374:menidipine; D009543:Nifedipine