Biology of Reproduction, Vol 21, 1143-1152, Copyright © 1979 by Society for the Study of Reproduction

Induction of Uterine Leukocytosis and Its Effect on Pregnancy in Rats

¹ Reproductive Physiology, Oregon Regional Primate Research Center, Beaverton, Oregon 97006

Glycogen, a leukocyte chemotactic agent, was used to induce transient leukocytosis in rat uteri during pregnancy. Large numbers of polymorphonuclear leukocytes (PMNLs) were attracted to the uterine endometrium and lumen after a single intrauterine injection of soluble glycogen (ligated horns) or glycogen-releasing gelatin beads (nonligated horns). Glycogen treatment on Days 3 through 5 of pregnancy (Day 5 = implantation) caused complete termination of pregnancy and significantly reduced fertility on Days 2 and 6 of pregnancy. However, fertility was unaffected by glycogen treatment after Day 6 of pregnancy even though a substantial leukocytic response was also elicited by glycogen in rats during later stages of gestation. This study indicates that glycogeninduced uterine leukocytosis effectively terminates pregnancy before and during the implantation stage. We propose that leukocyte chemotactic agents such as glycogen may prove clinically useful as abortifacient agents or may be used to improve the contraceptive efficiency of intrauterine devces.

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ACKNOWLEDGMENTS The research reported in this article, Publication No. 1058 of the Oregon Regional Primate Research Center, was supported by the Program for Applied Research on Fertility Regulation, Northwestern University, under contract AID/csd-3608. The authors wish to thank Mary Boudreaux and Belinda Toyooka for excellent technical assistance and Patsy Kimzey for helping with the preparation of this manuscript.