Effect of Testicle Extract on Primary Tuberculous Infection and Reinfection in Guinea Pigs

Abstract

1. Effect on Primary Infection. Testicle extract greatly increased the extent of the local lesions resulting from the intradermal or subcutaneous injection of virulent human tubercle bacilli into guinea pigs. When compared with lesions resulting from the injection of an equal number of tubercle bacilli suspended in salt solution, the increase was estimated at from 10 to 15 fold. The testicle extract was prepared by mincing bull testicle in 2 volumes of physiological salt solution, straining the material through cloth and finally filtering through a Berkefeld V candle. Kept at ice-box temperature, the extract maintains its activity for a long period of time. Two groups of 6 guinea pigs were used in the first experiment, in which the injection was made intradermally. One group was injected with a mixture of 1.0 cc. of testicle extract and 1.0 cc. of a suspension of H-37 strain of human tubercle bacilli in salt solution, containing 0.1 mg. of organisms, moist weight. The other group of 6 guinea pigs was injected with 2.0 cc. of a suspension of tubercle bacilli in salt solution, containing 0.1 mg. of organisms. The lesions resulting from these intradermal infections in the case of the testicle extract group were very large, spreading over the entire flank, from 5 to 6 cm. in width and from 7 to 8 cm. in length. The controls showed small nodules which ulcerated and drained, at the most 1.5 to 2.0 cm. in diameter.

A second experiment was performed using 2 groups of 10 guinea pigs, in which the injections were made subcutaneously in the groin. The dosage and quantities of testicle extract were the same as in the first experiment above.