Rate of carbon clearance in three strains of germfree mice

¹ Lobund Laboratory, Department of Biology, University of Notre Dame, Notre Dame, Indiana

Three strains of germfree mice (ND-1, ND-2, C₅₇), along with conventional controls, were compared in terms of their ability to rid the blood stream, via the reticuloendothelial system, of intravenously injected colloidal carbon. K values of ND-1 germfree mice were lower than values for their conventional controls, but there was no difference between ND-2 and C₅₇ germfree and their controls. Germfree ND-1 mice had lower K values than germfree ND-2 or C₅₇. Clearance rates were correlated to relative combined weights of liver and spleen. There was no significant difference in values among these animals, indicating that although the liver + spleen weights of ND-1 were lower, these organs were not atrophied or nonfunctional. When the germfree mice with smaller liver + spleen weights were "conventionalized," relative liver + spleen weight increased as did their K values. No such increase was noted with conventionalized ND-2 mice. In other laboratories, ND-1 mice were found to be more susceptible to infectious agents than ND-2.