Complete Inhibition of Occurrence of Spontaneous Hepatomas in Highly Susceptible (C3H × YBR)F₁ Male Mice by Hypophysectomy

Summary

No hepatomas occurred in genetically highly susceptible A^vA and Aa male (C3H × YBR)F₁ hybrid mice hypophysectomized at 6 weeks of age and maintained to the advanced age of 16 months. Hepatomas were found in 100 percent of the intact control A^vA male hybrids of the same age, with an average of 5.6 hepatomas per animal, and in 88 percent of the intact control Aa male hybrids of the same age, with an average of 3 hepatomas per animal. The greater occurrence of hepatomas in the A^vA than in the Aa controls confirms the previous observation that the A^v gene increases the occurrence of spontaneous hepatomas. The effect, on occurrence of neoplasms, of this gene and of other factors that influence normal growth is discussed.