Decreased beta-adrenergic receptor density in mononuclear leukocytes from thyroidectomized patients

Abstract. Beta-adrenergic receptor characteristics were investigated in peripheral blood mononuclear leukocytes taken from patients before and after partial thyroidectomy. In order to discriminate the effect of surgical stress per se from that of thyroidectomy, the analysis was also performed on patients before and after cholecystectomy. Receptor characteristics were determined by using dihydroalprenolol as ligand in direct equilibrium binding experiments. The binding affinity showed no changes either when two different surgical treatments were compared or when the same patient was analysed before and after the operation. On the contrary, a significant decrease in receptor density was found in thyroidectomized patients when compared pre- and post-operatively. This fall in receptor number seems to be linked with thyroid function since no statistically significant changes were observed in cholecystectomized patients in relation to surgical operation. This view is further supported by data on T3 serum levels, which show a significant fall after thyroidectomy but no statistically significant modifications after cholecystectomy. It is concluded that betaadrenoceptor modulation plays an important role in the relationship between thyroid and beta-adrenergic system.

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Left ventricular function and beta-adrenoceptors in rabbit failing heart

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1990.258.3.h634 ◽

1990 ◽

Vol 258 (3) ◽

pp. H634-H641 ◽

Cited By ~ 4

Author(s):

N. Gilson ◽

N. el Houda Bouanani ◽

A. Corsin ◽

B. Crozatier

Keyword(s):

Adrenergic Receptor ◽

Volume Overload ◽

Conscious State ◽

Left Ventricular ◽

Lv Function ◽

Receptor Density ◽

Beta Adrenergic Receptor ◽

Beta Adrenergic ◽

Beta Adrenoceptors ◽

Chronotropic Response

Few models of heart failure (HF) are available for physiological and pharmacological studies. We report here a model of pressure plus volume overload induced in rabbits in which left ventricular (LV) function was studied in the conscious state after instrumentation of the animals with LV pressure catheter and ultrasonic crystals measuring LV diameter. Beta-Adrenoceptors were studied on crude membranes obtained from control (C) and HF rabbits using [3H]CGP 12177. LV weights and end-diastolic diameters were significantly increased in the HF group compared with the C group (by 79 and 38%, respectively). The percentage of diameter systolic shortening was decreased, in the control state, in rabbits with HF (15.3 +/- 1.6%) as compared with C rabbits (29.6 +/- 2.5%) and remained lower in the HF group when end-systolic pressures were matched. Chronotropic response to isoproterenol injection was significantly decreased in rabbits with HF compared with that of C rabbits. Beta-Adrenergic receptor density was decreased in rabbits with HF (39.3 +/- 3.7 fmol/mg) compared with C rabbits (56.7 +/- 4.2 fmol/mg) without affinity changes. This model of chronic HF thus produces a marked hypertrophy with ventricular dilatation and a depression of LV function within 2 mo, factors that are associated with a reduced cardiac responsiveness to catecholamines and a decreased ventricular beta-adrenergic receptor density.

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Mechanisms of denervation supersensitivity in regionally denervated canine hearts

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.264.3.h815 ◽

1993 ◽

Vol 264 (3) ◽

pp. H815-H820 ◽

Cited By ~ 7

Author(s):

M. R. Warner ◽

P. L. Wisler ◽

T. D. Hodges ◽

A. M. Watanabe ◽

D. P. Zipes

Keyword(s):

Adrenergic Receptor ◽

Left Ventricular ◽

Receptor Density ◽

Beta Adrenergic Receptor ◽

Beta Adrenergic ◽

Functional Studies ◽

Denervation Supersensitivity ◽

Stimulatory G Protein ◽

Biochemical Analyses ◽

Gs Alpha

Mechanisms responsible for “denervation supersensitivity” in regionally denervated canine hearts were examined by measuring beta-adrenergic receptor density and affinity and the density of the alpha-subunit of the stimulatory G protein (Gs alpha). Sympathetic denervation was produced by applying an epicardial strip of phenol midway between the left ventricular (LV) base and apex. Six to eight days after denervation, dogs were anesthetized and then underwent functional studies (n = 4) or hearts were excised for biochemical analyses (n = 6). Biochemical studies were also done on 3 nondenervated hearts. Effective refractory periods (ERPs) were measured in innervated (base) and denervated (apex) LV myocardium. During sympathetic stimulation (2 and 4 Hz), the ERP shortened more (P < 0.05) at basal than at apical sites, whereas during norepinephrine infusion (0.05 to 0.5 mg.kg-1 x min-1), the ERP shortened more (P < 0.001) at apical than at basal sites. In regionally denervated hearts, however, the density and affinity of beta-adrenergic receptors did not differ significantly (P > 0.2) in nondenervated basal compared with denervated apical myocardium. Quantitative immunoblotting of the Gs alpha demonstrated that the density of the 47- and 52-kDa subunits was also similar (P > 0.6) in basal compared with apical myocardium from regionally denervated hearts. In addition, beta-adrenergic receptor density and affinity and Gs alpha density did not differ significantly (P > 0.5) in basal compared with apical myocardium from nondenervated control hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effect of age and hypoxia on beta-adrenergic receptors in rat heart

Journal of Applied Physiology ◽

10.1152/jappl.1991.71.6.2094 ◽

1991 ◽

Vol 71 (6) ◽

pp. 2094-2098 ◽

Cited By ~ 19

Author(s):

S. L. Mader ◽

C. L. Downing ◽

E. Van Lunteren

Keyword(s):

Adrenergic Receptors ◽

Adrenergic Receptor ◽

Left Ventricular ◽

Hypoxic Exposure ◽

Receptor Density ◽

Beta Adrenergic Receptors ◽

Beta Adrenergic Receptor ◽

Beta Adrenergic ◽

Young Rats ◽

Age Related

Previous reports suggest that hypoxia downregulates cardiac beta-adrenergic receptors from young rats. Because aging alters response to stress, we hypothesized an age-related alteration in the response to hypoxia. Male Fischer-344 rats, aged 3 and 20 mo, were divided into control and hypoxic groups. The hypoxic rats were exposed to hypobaric hypoxia (0.5 atm) for 3 wk. After hypoxic exposure, body weight decreased, hematocrit increased, right ventricular weight increased, and left ventricular weight decreased in all animals. beta-Adrenergic receptor density declined after hypoxic exposure in the young but not in the older animals, a change that was confined to the left ventricle. beta-Adrenergic receptor density in the right ventricle was significantly lower in the older animals than in the young animals. Plasma catecholamines (norepinephrine, epinephrine) drawn after the animals were killed (stress levels) decreased in young rats and increased in old rats after the exposure to hypoxia. Hypoxia is a useful physiological stress that elucidates age-related changes in cardiac beta-adrenergic receptor and catecholamine regulation that have not previously been described.

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Effect of eosinophil peroxidase on beta-adrenergic receptor density on guinea pig lung membrane

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(92)90261-i ◽

1992 ◽

Vol 189 (3) ◽

pp. 1613-1619 ◽

Cited By ~ 5

Author(s):

Shinji Motojima ◽

Takeshi Fukuda ◽

Sohei Makino

Keyword(s):

Guinea Pig ◽

Adrenergic Receptor ◽

Receptor Density ◽

Beta Adrenergic Receptor ◽

Beta Adrenergic ◽

Eosinophil Peroxidase ◽

Lung Membrane

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Skeletal muscle beta-adrenoceptor distribution and responses to isoproterenol in hyperthyroidism

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1992.262.4.e504 ◽

1992 ◽

Vol 262 (4) ◽

pp. E504-E510 ◽

Cited By ~ 3

Author(s):

W. H. Martin ◽

E. Korte ◽

T. K. Tolley ◽

J. E. Saffitz

Keyword(s):

Skeletal Muscle ◽

Adrenergic Receptor ◽

Human Skeletal Muscle ◽

Muscle Fibers ◽

Type I ◽

Receptor Density ◽

Adrenergic Stimulation ◽

Beta Adrenergic Receptor ◽

Beta Adrenergic ◽

Isoproterenol Infusion

To determine whether hyperthyroidism selectively increases beta-adrenergic receptor density in vessels or fibers of human skeletal muscle, we characterized beta-receptor distribution autoradiographically in muscle biopsies of 18 subjects aged 26 +/- 1 yr before and after daily administration of 100 micrograms 3,5,3'-triiodothyronine (T3) for 2 wk. To establish whether vascular and metabolic responses to beta-adrenergic stimulation are concomitantly altered, we quantified calf blood flow and plasma concentrations of glucose, lactate, glycerol, free fatty acids (FFA), insulin, and C-peptide during graded-dose isoproterenol infusion in eight of these individuals. Differences in beta-adrenergic receptor density among muscle fiber types and vascular components were highly significant (type I greater than type IIa greater than type IIb muscle fibers, P less than 0.001; and type I muscle fibers greater than resistance arterioles, P less than 0.05). Hyperthyroidism increased beta-adrenergic receptor density in all types of muscle fibers (+31-50%; P less than 0.01) but not in resistance arterioles. There was no change in calf blood flow or plasma glucose, glycerol, FFA, insulin, or C-peptide responses to isoproterenol. A rise in lactate during stages 3 and 4 of isoproterenol infusion (P less than 0.01) was observed before but not after T3 administration. Thus hyperthyroidism increases beta-adrenergic receptor density in fibers but not vessels of human skeletal muscle without increasing either metabolic or vascular responses to selective beta-adrenergic stimulation.

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