Acute and long-term effects of acebutolol on systemic and renal hemodynamics, body fluid volumes, catecholamines, active renin, aldosterone, and lymphocyte beta-adrenoceptor density.
Acebutolol is a relatively new beta-adrenoceptor blocking antagonist, possessing both beta 1-adrenoceptor selectivity and partial agonist activity (PAA). Its acute (24 h, 400 mg, twice daily) and long-term effects (3 weeks) on systemic and renal hemodynamics, body fluid volumes, hormones, and beta-adrenoceptor density on lymphocytes were studied in a single-blind placebo-controlled trial, in 10 hypertensive patients. The initial response to acebutolol (1-2 h) was a fall in heart rate (HR) (-9.6 +/- 2.7%), cardiac output (-16.0 +/- 3%), and stroke volume (SV) (-10.7 +/- 0.2%), and an increase in systemic vascular resistance (SVR) (18.0 +/- 3.9%). Mean arterial pressure (MAP) began to fall 2-3 h after dosing in parallel with a decrease in SVR. At the end of the acute study, MAP and SVR were decreased by 18.1 +/- 2.7% and 15.6 +/- 5.6%, respectively. By that time, HR and SV had returned to control values despite blockade of beta-adrenoceptors. After 3 weeks of treatment (mean dose of acebutolol 480 mg twice daily), the fall in MAP was 10.1 +/- 2.7% and HR was decreased by 13.0 +/- 2.3%. Renal blood flow and glomerular filtration rate did not change. Acute and long-term treatment had no effect on the density of lymphocyte-membrane beta-adrenoceptors. This could be explained by acebutolol's beta 1 selectivity or, alternatively, this could be due to the drug's PAA.
D000070:Acebutolol / Q000008:administration & dosage / Q000494:pharmacology*; D001834:Body Water / Q000032:analysis; D002395:Catecholamines / Q000378:metabolism*; D004334:Drug Administration Schedule; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage; D008214:Lymphocytes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D012079:Renal Circulation / Q000187:drug effects; D012083:Renin / Q000378:metabolism
D002395:Catecholamines; D011943:Receptors, Adrenergic, beta; D000070:Acebutolol; D012083:Renin; D007545:Isoproterenol