alpha-adrenergic blockade in preventing posttransplant edema of lung allograft

Effect of alpha-adrenergic blockers on pulmonary edema in lung transplantat ion was studied with a rat model of syngeneic left lung transplantation. Pr ior to harvesting, 0.1 mg of Prazocin or 0.4 mg of Yohimbin was given to th e donor. Pulmonary and systemic hemodynamics were measured under the right pulmonary arterial occlusion (RPAO) at different time points after grafting . Wet to dry weight ratio (W/D) of all transplants was also calculated. Sam e procedure was conducted in rats with normal and ischemic lung and in tran splanted animals without any treatments. While RPAO did not increase W/D in normal lung with a significant elevation in pulmonary arterial pressure (P AP), both these values significantly increased in transplanted lung. Transp lanted animals could not tolerate RPAO 24 hours after grafting, but mere to lerable later than 48 hours with elevated W/D and PAP. On the contrary, ani mals given Prazocin or Yohimbin mere all tolerable at 24 hours postsurgery. Yohimbin significantly improved W/D. Consequently, it was demonstrated tha t pulmonary edema of the graft reached its peak during first 24 to 48 hours after transplantation and was alleviated by the blockade of alpha-adrenerg ic recepter in the graft vessel. (C) 1999 Tohoku University Medical Press.