Date of Award
Master of Science
F. Neal Schrick
Jim Godkin, Alan Mathew
Two experiments were conducted to determine the effect of prostaglandin F2α, (PGF2α) on in vitro and in vivo development of preimplantation rat embryos. In Trial 1 of the first experiment, seven-hundred-twenty three 8-cell embryos from superovulated female Sprague-Dawley rats were collected four days after natural mating. Embryos were cultured in alpha- Minimum Essential Medium (αMEM) supplemented with 0.1% polyvinyl alcohol (control;n=179) or control medium supplemented with one of the following levels of prostaglandin F2α 1) 0.1 ng/ml(n=176) , 2) 1.0 ng/ml(n=176) or 3) 10 ng/ml(n=162). After 24 hours of incubation in their respective treatments, stages of embryonic development were recorded and morphologically normal embryos were transferred to control media for an additional 24 h. Following 24 h of culture, 63% of control embryos had continued development to the morula or blastocyst stage. However, only 20, 15, and 16% of the embryos treated with 0.1, 1.0, and 10 ng/ml PGF2α, respectively, continued development to the morula and blastocyst stage. All levels of prostaglandin F2α decreased the number of embryos developing to the expanded blastocyst stage after 48 h of culture (p<0.01). Furthermore, a second trial was performed in which embryos were placed with corpora lutea in 2 of 4 treatments, consisting of the following: 1)control (αMEM;n=30), 2)control-luteal (corpora lutea + αMEM;n=30), 3)PGF-luteal (corpora lutea + 10 ng/ml PGF2α;n=30) and 4)PGF-control (10ng/ml PGF2α +αMEM;n=41). The percentage of embryos in the CL + αMEM treatment that reached the blastocyst stage (43.3%) was not statistically different from the controls (37.8%;p>.10). However, the co-culture of corpora lutea and PGF2α tended (p<0.07) to increase the negative effects of PGFzc, on blastocyst development (19%) when compared to the PGF2α group.
To investigate the effects of PGF2a on in vivo development of preimplantation embryos, prostaglandin F2α (0.5 and 1 mg) was administered to rats twice daily during Days 4-7 of pregnancy. All animals were also injected with 4 mg/day of progesterone from Days 4-11 of treatment. On Day 11, animals were euthanized by CO2 overdose and the number of implantation sites determined. Prostaglandin F2α, was not effective in terminating pregnancy or reducing litter size.
These data suggest that increased levels of prostaglandin F2α, have a direct negative effect on in vitro embryonic development. However, exogenous PGF2α, had no effect on embryonic survival, suggesting that PGF2α may not attain embryotoxic concentrations within the uterus, possibly because of conversion to PGE2.
Buuck, Michael Joseph, "Effects of prostaglandin F₂α on in vitro and in vivo development of preimplantation rat embryos. " Master's Thesis, University of Tennessee, 1997.