Effects of diltiazem on down-regulation of lymphocyte beta-adrenoceptors in patients with chronic congestive heart failure.
OBJECTIVE
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.
Zhang
X L
XL
Department of Cardiology, Zhong Da Hospital, Southeast University, Nanjing 210009, China.
Xu
B
B
Feng
Y
Y
D001792:Blood Platelets / Q000378:metabolism; D002118:Calcium / Q000097:blood*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology*; D015536:Down-Regulation; D005260:Female; D006333:Heart Failure / Q000097:blood*; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011943:Receptors, Adrenergic, beta / Q000097:blood*
D002121:Calcium Channel Blockers; D011943:Receptors, Adrenergic, beta; D004110:Diltiazem; D002118:Calcium; D009638:Norepinephrine