Nephrotoxic serum nephritis in rats. I. Distribution and specificity of the antigen responsible for the production of nephrotoxic antibodies.

Studies have been carried out to determine the distribution of antigen capable of inducing the formation in rabbits of antibodies nephrotoxic for the rat. The results indicate that the antigen is present both in cortex and medulla of rat kidney. It can be extracted to a limited extent with saline. It is non-dialyzable and destroyed by boiling. The nephrotoxic serum antigen is also present in rat lung and placenta, in amounts roughly comparable to that in kidney, and in a number of other rat organs in smaller amounts. These various tissues not only are capable of stimulating the production of nephrotoxic antibodies, but each tissue is also able to absorb the nephrotoxic antibodies induced by injections of other rat tissues. These studies indicate that the nephrotoxic serum antigen in various rat tissues is the same or closely related. The nephrotoxic serum antigen of the rat is distinct from that of the dog and the rabbit, but there appears to be a cross-reaction between the nephrotoxic serum antigens of the rat and mouse. It is concluded that the nephrotoxic serum antigen is not a specific component of kidney; it is neither limited to kidney in its distribution within the rat, nor is the rat antigen present in kidney tissue of 2 other species examined. Rather, it is probable that the antigen is to a large extent specific for tissue of a given species. The preponderance of renal injury following injections of the anti-organ sera presumably is due to the occurrence in the kidney of large amounts of the antigen in positions of physiological importance in which it is exposed directly to the circulating antibodies.