THE INFLUENCE OF DECIDUAL TISSUE UPON PSEUDOPREGNANCY¹

Abstract

THERE seems to be a difference of opinion regarding the influence of decidual tissue upon the duration of pseudopregnancy in rats and mice. Ershoff and Deuel (1943) and Peckham and Greene (1948) found that deciduomata extended the period of pseudopregnancy in the rat which is at variance with the results obtained earlier by Astwood and Greep (1938) and also with the observations by Kamell and Atkinson (1948) on mice. It seems now that this lack of agreement probably was due to differences in size of deciduomata as Olsen et al. (1951) have found that pseudopregnancy in rats is prolonged beyond its normal duration in proportion to the amount of decidual tissue present. The present paper includes an extension of these observations on the quantitative relationship between the amount of decidual tissue and the length of pseudopregnancy as well well as information contributing to an explanation of the reaction.