Beta-adrenoceptor antagonist therapy in hyperthyroidism: effects on lymphocyte metabolic activity and the relation between aerobic and anaerobic metabolism in lymphocytes

Thyroid hormones are of major importance for the regulation of metabolic activity at the cell level in humans. An increased heat production has been demonstrated in lymphocytes from patients with hyperthyroidism. However, the lymphocyte oxygen consumption was not increased, indicating an increased dependency on anaerobic metabolism in lymphocytes exposed to thyroid hormone excess. The present study focused on the effects of beta-adrenoceptor antagonists on the metabolic activity in lymphocytes from hyperthyroid patients. Lymphocytes from patients on treatment with these drugs showed a heat production that was at a level similar to that of cells from normal subjects and significantly lower than lymphocytes from patients before treatment for hyperthyroidism and not on beta-blockers. Similarly, lymphocyte oxygen consumption was of the same order in hyperthyroid patients on beta-blockers as in euthyroid subjects. Treatment with beta-adrenoceptor antagonists seems to preclude an increase in the metabolic activity of lymphocytes, otherwise present in hyperthyroid patients. These data suggest that beta-adrenoceptor activity may play a role in the enhanced metabolic activity of these cells during thyroid hormone excess. A stimulating effect of thyroid hormones on the sensitivity of adrenoceptors might thereby be of greater importance than the calorigenic effect exerted