Tumor necrosis factor-like cytotoxicity and anorexia in Ascaris suum infected pigs.

Tumor Necrosis Factor-Like Cytotoxicity (TNF-LC) was examined in sera from 12 pigs experimentally infected with Ascaris suum. The difference of TNF-LC levels between eight infected and four uninfected controls was not significant. When an endotoxin challenge was intravenously administered 1 month after the first dose of A. suum, the levels of TNF-LC in the sera of infected pigs were one-third that of the controls 125 min post-challenge (PC). In a more detailed study on four infected and two uninfected control pigs, TNF-LC was monitored every 10-15 min until 125 min after endotoxin challenge. The TNF-LC levels in these pigs increased at 40 min PC, reached maximum in another 10-25 min and then decreased. This pattern was seen in all except one infected pig. The infected pigs showed milder shock symptoms and their serum TNF-LC levels returned to pre-challenge levels 30 min earlier than controls.