Dietary glucarate-mediated reduction of sensitivity of murine strains to chemical carcinogenesis.

Serum beta-glucuronidase activity is shown to differ quantitatively in the following strains of mice, listed in order of increasing activity: C3H, C57BL/6 less than BALB/c, DBA/2, ICR less than SENCAR, A/He. The level of the enzyme in the murine strains is shown to correlate with the urinary excretion of 17-ketosteroids, which in turn reflects the endogenous level of androgens. Dietary calcium D-glucarate, an in vivo beta-glucuronidase inhibitor, reduced the steady state level of both beta-glucuronidase and 17-ketosteroid excretion in the highly susceptible A/He and SENCAR strains to that of strains known to be resistant to chemical carcinogenesis. Sensitivity of the A/He strain is significantly reduced by dietary calcium glucarate, which is shown to inhibit DNA binding and the induction of pulmonary adenomas by benzo[a]pyrene.