Modification of hyperacute canine renal homograft and pig-to-dog heterograft rejection by the intra-arterial infusion of citrate.

Abstract

Recent studies from our laboratories have attempted to clarify the events of hyperacute heterograft and homograft rejection.1, 7, 15, 17, 18 These investigations, as well as those from other laboratories, 3, 5, 6, 14 have emphasized the complexity of this fulminating variety of rejection as well as the nearly simultaneous contributing roles played by preformed humoral antibodies, coagulation, formed blood elements, and complement. It might be anticipated that therapy which interfered with the foregoing etiologic factors could mitigate the vigor of hyperacute rejection. Furthermore, if heterografts and homografts transplanted to naturally or deliberately presensitized recipients undergo rejection by analogous mechanisms, successful treatment under either of these experimental conditions should be applicable to both. In this communication, it will be shown that sodium citrate, a calcium-binding agent, has the same type of ameliorating effect upon heterograft rejection as has already been reported by Linn and associates11 upon hyperacute homograft rejection. Since free calcium ions are required for coagulation, for complement activation, and for a number of other biologic processes, it cannot be stated unequivocally by what means the protection occurred.