Reduced sensitivity to catecholamine in Werner's syndrome fibroblasts.

The beta-adrenergic receptor-coupled adenylate cyclase system has been investigated in normal and Werner's syndrome fibroblasts. The basal levels of cAMP in Werner and normal control cells were similar, whereas the isoproterenol-induced increase in cAMP levels was far less for Werner cells than for control cells. In the broken cell preparations isoproterenol stimulated the adenylate cyclase of only control cells, not of Werner cells, although NaF or prostaglandin E1 stimulated the enzyme of both cells to the same extent. The beta-adrenergic receptor concentrations analyzed with hydrophilic radioligand were nearly equal in Werner and in control cells. A reduction of functional activity of the beta-adrenergic receptor in Werner cells is thus suggested.