ConclusionThere is a continuing debate in regard to the relative contribution of TGF and myogenic mechanisms in the control autoregulation in the kidney. Much of the controversy, relating to the relative importance of each mechanism can possibly be explained simply by considering the species from which evidence is derived. Differences in autoregulatory behavior between the rat and the dog, as noted by Navar et al. (20), have been attributed by some investigators to the effects of anesthesia (8). However. in the current review, most of our comparisons were based on data obtained from anesthetized rats and dogs. Thus we propose that the factors responsible for autoregulatory control are indeed different between the dog and the rat. It is our opinion that based on the available evidence. TGF plays a substantial role in the autoregulation of RBF in the dog, while having only a minimal influence in the rat.