Contractile Hyporesponsiveness to Norepinephrine of Forearm Veins in Chronic Renal Failure

The results demonstrate that norepinephrine-mediated contractions of forearm veins are markedly decreased in dialyzed patients. Endothelium-derived relaxing factors are not involved in this effect. The reduced contractile response is most likely caused by a decreased calcium entry through voltage- and receptor-dependent calcium channels.