ENDOCRINE FACTORS INFLUENCING TUMOR DEVELOPMENT, THE EFFECT OF THE GONADOTROPINS AND OF THEEL1N UPON THE MARSH-BUFFALO ADENOCARCINOMA AND LYMPHQSARCOMA1

Abstract

Parenteral adm. of prolan, equine gonadotrophin, or pituitary gonadotrophic preps. produced acinar development of the mammary gland in the young (2 mos.) Marsh-Buffalo mouse comparable to that found at the age of 1 yr. Exogenous theelin even in sublethal doses failed to produce this effect. Sublethal doses of theelin (3.8 rag. per mouse in 5 mos.) were required to enhance carcinogene-sis in the Marsh-Buffalo virgin [female] mouse. The increase obtained for both the adenocarcinoma of the breast and for lymphosarcoma was only doubtfully significant. Prolan failed to influence the onset of the adenocarcinoma of the breast or lymphosarcoma in virgin [female][female] whether first administered before sexual maturity (720 u. per mouse in 12 mos.), whether first dosed at the age of 60-90 days (660 u. per mouse in 9 mos.), or whether given in massive doses (2700 u. per mouse in 9 mos.). Pregnant mare''s serum (750 u. per mouse in 11 mos.) and purified pregnant mare''s serum hormone (950 u. per mouse in 14 mos.) significantly retarded the onset and decreased the incidence of adenocarcinoma in virgin [female] mice. Either subcut. or intraperit. injs. of pituitary gonadotrophic hormone prep. over a period of 13 mos. significantly retarded the onset and decreased the incidence of adenocarcinoma in virgin [female] mice. Mice which had received the intermittent doses of prolan, mare''s serum preps. and pituitary gonadotrophic preps. became pregnant after 1 yr. of treatment. Marsh-Buffalo mice were cancer susceptible and theelin resistant when compared with other cancer susceptible strains of mice.