Razi Journal of Medical Sciences

The development of radioligand - binding studies has greatly advanced our knowledge of the molecular pharmacology of beta - adrenoceptors. Using this technique it became possible for the first time to directly determine the tissue concentration of beta - adrenoceptors, and by this, the responsiveness of tissues to beta - adrenergic stimulation. One major insight into the molecular pharmacology of beta - adrenoceptors to come from radioligand - binding studies was that the tissue concentration of beta - adrenergic is not a fixed number, but is rather dynamically regulated by a variety of drugs, hormones, physiological and pathologic conditions.

In addition to the changes that occur in receptor characteristics, post - receptor events may be influenced by different pathologic states which in turn affect beta - adrenoceptor responsiveness.