H-2, Ah, and aging: the immune response and the inducibility of P-450 mediated monooxygenase activities, xanthine oxidase, and lipid peroxidation in H-2 congenic mice on C57BL/10, C3H, and A strain backgrounds.

The effects of beta-naphthoflavone (beta-NF, 80 mg/kg i.p. for 2 consecutive days) on P-450-dependent and -independent enzymes, lipid peroxidation and xanthine oxidase were investigated in 9 strains of young (3-month-old) male mice. Three H-2 congenic strains on each of three different genetic backgrounds were studied. The backgrounds were C57BL/10 (abbreviated as B10), C3H, and A strain mice. The reported longevities (weeks) as expressed in 10th decile of survivorship are significantly different among the H-2 congenic strains on each of these backgrounds: it ranges from 155 to 170 weeks in B10, from 138 to 150 in C3H and from 114 to 134 in A background mice. The inducibility of aryl hydrocarbon hydroxylase (AHH) with beta-NF was highest in B10, intermediate in C3H/He and non-inducible in other C3H mice and in all mice on the A strain background. Within the B10 background, inducibility of AHH varied widely among mice of different H-2 haplotypes: 549 +/- 34 (H-2k), 360 +/- 72 (H-2b) and 349 +/- 47 (H-2r) percent of the mean control values (n = 5; mean +/- S.D.), without change in activities of P-450-independent enzymes. In C3H mice the H-2k haplotype showed inducibility (213 +/- 34%), while other haplotypes, specifically H-2b and H-2j, did not. beta-NF increased the activities of xanthine oxidase in B10 and A background strains, without interbackground differences. Lipid peroxidation was significantly increased in A background strains and in an H-2 dependent manner. The relationship between Ah responsiveness and reported longevities of these nine strains is discussed.