Abstract: | Parasiticidal activity of normal peritoneal exudate cells on microfilariae of Dirofilaria immitis in diffusion chambers implanted into normal guinea pigs was evoked by intraperitoneal passive transfer of anti-D. immitis serum. The immune serum was fractionated into supernatant and sediment by ammonium sulfate precipitation. The parasiticidal effect was reproduced with the supernatant and, to a less extent, with the sediment. Anti-D. immitis serum from the animals sensitized 5 days before was also effective in this respect. From these results it can be concluded that the factor responsible for the phenomenon is some other factor(s) than the antibody. In addition, the in vitro cytotoxicity test demonstrated an enhanced Mf-killing activity of sensitized peritoneal exudate cells by adding with anti-D. immitis serum. |