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. 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 wre determined by using dihydroalprenolol as ligand in direct equilibrium binding experiments. The binding affinity showed no changes when 2 different surgical treatments were compared or when the same patient was analyzed 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 [triiodothyronine] serum levels, which show a significant fall after thyroidectomy but no statistically significant modifications after cholecystectomy. .beta.-Adrenoceptor modulation apparently plays an important role in the relationship betwewen the thyroid and .beta.-adrenergic system.