In Vivo Studies on Precipitin Production by the Rabbit Spleen

Abstract

Three-kilogram rabbits were injected intravenously, intrasplenically and intraportally with 4 or 40 mg of alum-precipitated bovine γ globulin (BGG). At both dosage levels the peak precipitin responses were as follows: intravenous >; intrasplenic = intraportal. Antibody responses of small groups given soluble BGG were intravenous = intraportal > intrasplenic. In an attempt to determine any correlation between antigen concentration in an organ and serum antibody levels, the distribution of soluble and alum-precipitated I¹³¹ human serum albumin (HSA) was studied in certain organs of normal rabbits at 15 minutes and 24 hours after intravenous, intrasplenic and intraportal injections. No good correlation was found. An unexpected finding was that, when injected intravenously, eight times as much antigen was found in the lungs 15 minutes after alum-precipitated antigen as after soluble antigen. Splenectomized rabbits produced about 40% as much antibody as controls following intravenous injection of alum-precipitated BGG.