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I.—On the Pregnancy Rate in the Lactating Mouse and the Effect of Suckling on the Duration of Pregnancy

Published online by Cambridge University Press:  15 September 2014

L. Mirskaia  and
F. A. E. Crew
L. Mirskaia
Affiliation:
Department of Animal Genetics, University of Edinburgh
F. A. E. Crew
Affiliation:
Department of Animal Genetics, University of Edinburgh
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Summary

1. The pregnancy rate of primiparæ, suckling their young, was, in this experiment, 24·1 per cent.; that of multiparæ suckling their young, 50 per cent. It is shown that this difference is not due to differences in the incidence of ovulation associated with postpartum œstrus. The suggested explanation of this difference between puberal and adult groups is that a certain level of somatic maturity is a prerequisite for full reproductive activity.

2. In all cases the duration of pregnancy was prolonged. The degree of prolongation was variable and could not be related to the number of young in the uterus or suckling. The results provide no support for the suggestion that this prolongation, due to delayed implantation of the fertilised ova, is to be referred to an inhibitory action on the part of the mammary gland. The suggestion is made that the delayed implantation and prolonged pregnancy are due to inability on the part of the corpus luteum to cater adequately for implantation and lactation synchronously.

Type
Proceedings
Information
Proceedings of the Royal Society of Edinburgh , Volume 51 , 1932 , pp. 1 - 7
Copyright
Copyright © Royal Society of Edinburgh 1932

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References

BIBLIOGRAPHY

Clauberg, C. (1930), “Experimentelle Untersuchungen zur Frage eines Mäusetestes für des Hormon des Corpus luteum,” Zentralbl. für Gynaekologie, 19.Google Scholar
Corner, G. W., and W. M., Allen (1929), “Physiology of the Corpus Luteum. II. Production of a Special Uterine Reaction (progestational proliferation) by Extracts of the Corpus Luteum,” Amer. Jour. Phys., 88, 326.Google Scholar
Crew, F. A. E., and Mirskaia, L., (a) (1930), “On the Effect of the Removal of the Litter upon the Reproductive Rate of the Female Mouse,” Quart. Jour. Exp. Phys., 20, 3; (b) (1930), “The Lactation Interval in the Mouse,” Quart. Jour. Exp. Phys., 20, 2.Google Scholar
Daniel, J. Frank (1910); “Observations on the Period of Gestation in White Mice,” Jour. Exp. Zool., 9, 1.Google Scholar
Grüter, F. (1930), “Experiments upon the Effect of Hormones upon Milk Secretion with Special Reference to the Cow and the Goat,” Proc. Second Internat. Cong., Sex Res. (in press).Google Scholar
Kirkham, W. B. (1916), “The Prolonged Gestation Period in Suckling Mice,” Anat. Rec., 2, 2; (1918); “Observations of the Relation between Suckling and the Rate of Embryonic Development in Mice,” Jour. Exp. Zool., 27.Google Scholar
Mirskaia, L., and Crew, F. A. E. (1930), “On the Genetic Nature of the Time of Attainment of Puberty in the Female Mouse,” Quart. Jour. Exp. Phys., 20, 4.Google Scholar