STUDIES ON THE UTERUS

Abstract

From observations of 47 ? rabbits Reynolds concludes that marked uterine activity in the non-pregnant rabbit is associated with oestrus. Feeble activity has been twice seen in oestrus; moderate activity has been seen 7 times. Anoestrus is usually associated with only feeble activity, or none at all. The motility of the uterus of a rabbit deprived of its ovaries during oestrus becomes irregular and progressively less in 2-4 days. Complete quiescence eventually supervenes. The change has been demonstrated in the same rabbit, by obtaining records both before and after castration. Replacement therapy in castrate rabbits with Theelin and Estrogen, commercial water and lipid soluble oestrogenic extracts, may impart to the quiescent uterus activity such as usually occurs in the presence of the ovaries during oestrus. Hence the author concludes that the ovary of the non-pregnant rabbit normally exerts a profound effect upon the motility of the uterus. Occasional irregularities in uterine motility seen during oestrus indicate that certain unknown extra-ovarian influences sometimes modify or completely annul the effect of the ovary on the motility of the uterus. The minimal effective dose of Theelin as administered was less than 2 rat units per kgm. body wt. in recently castrated rabbits. In rabbits ovari-ectomized for 3 weeks, 20 rat units per kgm. is the minimal effective dose.