Abstract
γM alloantibody (allo γM) was produced in Lewis (Le) rats after a 5- to 7-day residence of Brown Norway (BN) renal grafts. The isolated, purified and isotopically labeled allo γM fixed to spleen, lung, liver and erythrocytes after intravenous injection into BN target rats, but did not fix to kidney unless the renal vein was clamped for 3 min. Allo γM fixed promptly in BN kidneys grafted into Le recipients. In such kidneys allo γM specifically bound to endothelia of glomerular and intertubular capillaries and of medium-sized arteries. It did not bind in vivo to renal tubular cells but did so in vitro. At least two γM antibodies were detected. One reacted with kidney, spleen cells and erythrocytes, the second only with spleen cells. Intravenous infusion of allo γM into target BN rats produced extensive pulmonary hemorrhages but the production of these lesions lacked specificity. Allo γM elicited by renal graft was strain but not organ specific, i.e., it reacted with transplantation antigens shared by kidney and by other organs and tissues of the immunizing strain. Its role in the rejection process could not be established.