Differences in tumour necrosis factor productive ability among rodents.

Large differences in tumour necrosis factor (TNF) productive ability 05337257erved among various strains of mice. DDY, CD-1, ICR and DBA/2 mice could produce a high titre of TNF activity, whereas Balb/c, C3H/HeJms and A/J mice produced a low titre of TNF activity. Administration of 200 micrograms/mouse of LPS to some strains of mice, i.e. DDD and C57B1/6J resulted in good production of TNF. ICR nu/nu mice produced the highest TNF activity among the nude mice. Balb/c nu/nu and DDD nu/nu mice exhibited very low titres of TNF activity. Nude mice required a rather higher dose of the priming agent, Propionibacterium acnes, than heterozygote littermates. Although it is commonly accepted that dual stimulation is necessary for TNF production, TNF activity was detected without the priming agent in SD rats and Golden hamsters by single injection of LPS. In these animals, much higher TNF production was observed after Propionibacterium acnes treatment than after a single injection of LPS. Large differences in TNF productive ability also existed among strains of rats. Although all animals receiving priming agents revealed hyperplasia of reticuloendothelial system, the sensitivity of the animals to LPS is considered to be the most important factor in their TNF productive ability.