An experimental approach to the breast cancer, reserpine problem.

Reserpine was administered intraperitoneally 3 times weekly to inbred female Syrian BIO hamsters of the 15.16 strain previously shown to be susceptible to methylcholanthrene (MC) induction of mammary cancer. Other groups of hamsters received non-carcinogenic doses of MC along with the reserpine administrations, and an additional group received a carcinogenic dose of MC alone. This last group demonstrated that BIO 15.6 females were indeed susceptible to MC mammary cancer induction, since 4 mg of MC administered by stomach tube (a total dose of 200 mg) caused mammary cancer in 52% of the animals. Mammary cancer was not observed in any of the animals given reserpine or reserpine in combination with the non-carcinogenic dose of MC.