Impaired regulation of beta-adrenoceptors in patients on maintenance haemodialysis.

Abstract

In patients on maintenance haemodialysis the number of lymphocyte beta 2-adrenoceptors (determined by (+/-)-125 iodocyanopindolol binding) was not different from that in healthy controls; lymphocyte cyclic AMP responses to (-)-isoprenaline (10(-8)-10(-4) M) or NaF (10 and 50 mM), however, were significantly reduced. Dynamic exercise on a bicycle (80% of maximum heart rate) for 15 minutes caused in 10 healthy volunteers a fourfold increase in plasma catecholamines; concomitantly lymphocyte beta 2-adrenoceptor number increased by about 55 per cent. In contrast, in patients on maintenance haemodialysis exercise induced only a twofold increase in plasma catecholamines and did not affect beta 2-adrenoceptor number. It is concluded that in chronic uraemia regulation and responsiveness of beta-adrenoceptors is impaired.