Regulation of Human Leukocyte Beta Receptors by Endogenous Catecholamines

Abstract

Ten niessee 37232 AB S T R A C T High levels of beta receptor agonist have previously been showin to dowvn-regulate beta receptor density on circulating leukocytes in man; however, the factors controlling receptor density under physiological conditionis have not previously beein de-fined. To determine whether beta receptor density is normally down-reguilated by circulating, physiological levels of catecholamlines we have examined the relationship between receptor density and catecholamine levels. Urinary epinephrine and norepinephrine were significantly reciprocally correlated to lymphocyte receptor density. A similar relationship existed between beta receptor density and supine plasma epinephrine, norepinephrine, upright epinephrine, and norepinephrine levels. Change in sodium intake from 10 to 400 meq/d cauised a 52% increase in lymphocyte and a 48% increase in polymorphonuclear beta receptor density. The changes in receptor density were accompanied by an increase in the sensitivity to isoproterenol measured as a fall in the dose of isoproterenol required to raise the heart rate by 25 beats per minute. Beta receptor density on both lymphocyte and polymorphonuclear cells was significantly correlated to the cardiac sensitivity to isoproterenol.

Participation of endogenous catecholamines in the regulation of left ventricular mass in progeny of hypertensive parents.

“…These are smaller than those obtained with antihypertensive therapy in patients with established hypertension. " 14 19 However, this discrepancy is not surprising since the follow-up periods in those studies were longer than ours. Furthermore, hypertensive individuals have greater LVM than our subjects, who were still normotensive, and it has been demonstrated29 that there is a significant correlation between the initial LVM and the magnitude of the change in this parameter induced by therapy.…”

Neonatal Adaptation: Cardiac Adrenergic Effector Mechanisms after Birth in Newborn Sheep

“…BAR down-regulation also occurs in response to chronic in vivo adrenergic stimulation. Both elevated endogenous catecholamines and exogenous administration of selective @-agonists result in reduced leukocyte or adipocyte BAR density if exposure is prolonged for several days to weeks (6)(7)(8)(9)(10).…”

“…This contention is based on data supporting rapid alterations of receptor density (4,5). However, after prolonged adrenergic stimulation, receptor recovery is reported to occur over several days to weeks (6)(7)(8)(9). Furthermore, if undetected fluctuations of Bmax did occur, they were not reflected by depressed cardiovascular function or instability.…”

Effects of chronic metoprolol and sulphinpyrazone on human lymphocyte beta‐adrenoceptors.

“…However the effect of such therapy on human lymphocyte ,B-adrenoceptors is still an open question. After chronic propranolol ,Badrenoceptors were found increased (Aarons et al, 1980;Fraser et al, 1981), unchanged (Zohar et al, 1983) or decreased (Goldstein et al, 1981) while prolonged pindolol treatment induced a marked and persistent receptor decrease (Molinoff & Aarons, 1983). The experimental procedures and the treatment schedule of all these studies, including ours, differed widely, making it hard to compare them directly and impossible to draw any firm conclusions.…”