Effects of prostaglandin F₂α on in vitro and in vivo development of preimplantation rat embryos

Author

Michael Joseph Buuck

Date of Award

5-1997

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

F. Neal Schrick

Committee Members

Jim Godkin, Alan Mathew

Abstract

Two experiments were conducted to determine the effect of prostaglandin F_2α, (PGF_2α) 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 F_2α 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 PGF_2α, respectively, continued development to the morula and blastocyst stage. All levels of prostaglandin F_2α 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 PGF_2α;n=30) and 4)PGF-control (10ng/ml PGF_2α +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 PGF_2α tended (p<0.07) to increase the negative effects of PGFzc, on blastocyst development (19%) when compared to the PGF_2α group.

To investigate the effects of PGF2a on in vivo development of preimplantation embryos, prostaglandin F_2α (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 F_2α, was not effective in terminating pregnancy or reducing litter size.

These data suggest that increased levels of prostaglandin F_2α, have a direct negative effect on in vitro embryonic development. However, exogenous PGF_2α, had no effect on embryonic survival, suggesting that PGF_2α may not attain embryotoxic concentrations within the uterus, possibly because of conversion to PGE₂.

Recommended Citation

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.
https://trace.tennessee.edu/utk_gradthes/6788