The role of thyroid hormones in the control of beta-adrenergic receptors in rat mammary gland.

We have studied the effect of hyperthyroidism and hypothyroidism on the lactating rat mammary gland number of beta-adrenergic receptors and basal intracellular cyclic AMP levels. We also describe the effects of isoproterenol, cholera toxin and forskolin challenge on these parameters. Using cyclic AMP levels as an indication of receptor functionality our results indicate that both thyroid states are accompanied by a decrease in the response to beta-adrenergic receptor stimulation.