Effects of diltiazem on down-regulation of lymphocyte beta-adrenoceptors in patients with chronic congestive heart failure
Abstract
"AIM:
To determine whether diltiazem could reverse down-regulation of lymphocyte beta-adrenoceptor (beta-AR) in patients with chronic congestive heart failure (CHF).
METHODS:
Before and after the treatment with diltiazem in CHF patients, lymphocyte beta-AR density was measured with [3H]dihydroalprenolol radioligand binding assay, levels of free cytosolic calcium ([Ca2+]i) in platelets were estimated with fluorescent indicator Fura 2-AM, plasma norepinephrine (NE) levels were measured with 125I-radioimmunoassay.
RESULTS:
Lymphocyte beta-AR density was lower and [Ca2+]i in platelets was significantly higher in CHF patients than those in control. Plasma NE levels were higher in CHF patients than those in control. Diltiazem therapy reduced [Ca2+]i in platelets and increased lymphocyte beta-AR density in CHF patients without significant change of plasma NE concentration.
CONCLUSIONS:
Diltiazem partly reversed down-regulation of lymphocyte beta-AR density in CHF patients, and this effect was not related to the level of plasma NE, and might be attributed to intracellular [Ca2+]i decrease."
Keywords:
To determine whether diltiazem could reverse down-regulation of lymphocyte beta-adrenoceptor (beta-AR) in patients with chronic congestive heart failure (CHF).
METHODS:
Before and after the treatment with diltiazem in CHF patients, lymphocyte beta-AR density was measured with [3H]dihydroalprenolol radioligand binding assay, levels of free cytosolic calcium ([Ca2+]i) in platelets were estimated with fluorescent indicator Fura 2-AM, plasma norepinephrine (NE) levels were measured with 125I-radioimmunoassay.
RESULTS:
Lymphocyte beta-AR density was lower and [Ca2+]i in platelets was significantly higher in CHF patients than those in control. Plasma NE levels were higher in CHF patients than those in control. Diltiazem therapy reduced [Ca2+]i in platelets and increased lymphocyte beta-AR density in CHF patients without significant change of plasma NE concentration.
CONCLUSIONS:
Diltiazem partly reversed down-regulation of lymphocyte beta-AR density in CHF patients, and this effect was not related to the level of plasma NE, and might be attributed to intracellular [Ca2+]i decrease."