Effect of casting on forearm resistance vessels in young men.

The aim of this study was to determine whether physical deconditioning, induced by 6 wk of forearm casting, and the conditioning effects of recovery from casting would elicit changes in the response of forearm resistance vessels to substances that modulate vascular resistance. Forearm blood flow (FBF) responses to intrabrachial infusion of NGmonomethyl-L-arginine (LNMMA) and norepinephrine (NE) were examined in six subjects recovering from Colles', scaphoid, or metacarpal fractures within 72 h of cast removal and again after a 6-wk recovery period. Vascular responses were also examined in six noncasted controls. The FBF responses of casted and control subjects did not differ, and no changes occurred over the 6-wk study period. These results suggest that the effect of forearm casting and recovery from casting do not greatly influence control of vascular tone, including the basal activity of the NO dilator system in vivo.