Changes in Pulsatile Blood Flow in Autograft and Homograft Kidneys During Rejection

It is now established that a decrease in the blood flow of the homograft is an early sign of homograft rejection. In order to examine this decrease in blood flow carefully, a model was designed to permit daily serial measurements of pulsatile renal artery blood flow in unanesthetized animals having both an autograft and a homograft kidney. It was demonstrated that blood flow to a homograft kidney progressively decreases as rejection occurs, while blood flow to an autograft kidney in the same animal is unchanged. This decrease in homograft blood flow was accompanied by a change in the pulsatile pattern of the homo-graft renal artery blood flow, which was noted as early as the 2nd post-transplant day. The altered pulsatile flow pattern can be temporarily converted to a normal pattern by the intraarterial injection of vasodilating agents, provided that the injection is given before the late stage of rejection.