Free epinephrine in the ischemic blood of muscle transplants in the rabbit.

A stimulated autotransplantation of the rectus femoris muscle in the rabbit was performed by clamping of the blood vessels for 2 h and cutting and suturing of the nerve. Four months after this operation, isometric contractions of the reinnervated muscle were recorded. Comparing controls and postoperation cases, the recovered strength measured about 65%. Due to operation stress, the epinephrine content in plasma was about 420 pg/ml; in plasma of the ischemic muscle it was enhanced to more than 600 pg/ml. During or immediately after ischemia, conjugated epinephrine is assumed to be converted to the free hormone. In systemic blood additionally about 200 pg/ml epinephrine were identified as glucuronides. The activity of adenylate cyclase increased, while the acetylcholine esterase decreased to one-half after nerve cutting.