Infertility in female guinea pigs injected with testis.

Abstract

The degree of fertilization failure and embryo loss was measured in female guinea pigs injected with guinea pig testis homogenate and Freund’s adjuvant. Controls were injected with saline and adjuvant. The fertilization rate was 91.6% in 26 control animals and 88.0% in 36 experimental animals. Embryo survival was estimated by comparing the number of normal fetuses at 25 or 60 days of gestation with the number of corpora lutea adjusted for fertilization rate. The average percentage of embryos surviving in 46 antigen-treated females was 45.8 compared to 72.7 in 19 controls. Embryo loss usually involved whole litters and occurred early enough for the females to return to estrus by 15.8 ± 3.2 days. Prebreeding estrous cycles on the same animals averaged 14.8 ± 1.0 days. These results indicated that, in guinea pigs injected with testis and adjuvant, the major cause of infertility is early embryonic death. The mechanism is not known but is presumed to involve a reaction of antibodies in the uterus with antigens borne by the embryo.