Brief Definitive Report Effect of Ingested Sperm on Fecundity in the Rat

T h e control o f female fertility by al imentary tract vaccination with sperm antigens has remained a theoretical possibility connect ing observations of sperm immunogenici ty and consequent infertility in various species, including humans (for review see references 1-3), with the translation o f gut mucosal immune reactivity to anatomically r emote mucosal sites, including the female genital tract (4-6). Here one reports that the intragastric administrat ion of live epididymal rat sperm to adult isohistogeneic female virgin rats resulted in shortto longterm infertility related to the appearance o f antisperm antibodies in genital tract secretions. This finding supports the concept of a common mucosal immune system (7) in that an immune response to non-self tissue antigens genera ted in gut-associated lymphoid tissues may be expressed at o ther mucosal sites and that such a response to sperm antigens in the female genital tract may diminish fecundity.