'Gelbsilber' rabbits: a closed colony of high responders to the lactic dehydrogenase isoenzyme LDH-H4. Possible mechanisms controlling the response.

'Gelbsilber' (GS) rabbits which had been maintained for an unknown time as a closed colony, were found to respond uniformly well to the pig lactic dehydrogenase isoenzyme of the H4 type (P-LDH-H4), to which most New Zealand white (NZW) rabbits produced no detectable antibody. Two to three per cent of the splenic lymphoid cells of GS rabbits after secondary immunization were found to produce antibody to P-LDH-H4, while no such cells were detected in NZW rabbits. No differences were detected between the electrophoretic mobility of endogenous LDH of GS and NZE rabbits. The immunoglobulins of GS rabbits were heterogeneous with respect to immunoglobulin light and heavy chain allotypes. It was concluded that in GS rabbits the response to LDH-H4 is controlled by and Ir gene and that these animals might be useful in studying the genetic control of the immune response in rabbits.