Date of Completion

9-9-2013

Embargo Period

9-9-2013

Keywords

PGE2, PGF2α, cellular respiration, steroidogensis, mitochondria

Major Advisor

Thomas A. Hoagland

Associate Advisor

John A. McCracken

Associate Advisor

John W. Riesen

Associate Advisor

Robert A. Milvae

Associate Advisor

Jacob P. Harney

Field of Study

Animal Science

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Mitochondria are essential to the process of cell respiration and steroidogenesis. Both of these processes impact the viability of the corpus luteum, which is required to maintain early pregnancy. In cattle and other species, progesterone supports gestation, regulates embryogenesis and works in concert with estrogen to maintain the reproductive tract. Many investigators have sought to understand the processes that control regression of the corpus luteum. Two prostaglandins, PGF2a and PGE2, have been implicated in the functioning of this transient gland. It is accepted by most researchers that the primary luteolysin responsible for functional and structural demise of the corpus luteum is PGF2a. However, there is ambiguity between reported effects of PGF2a and PGE2 on whole cells and on animals in vivo. Therefore, the specific effects of these prostaglandins on oxygen consumption and progesterone secretion in mitochondria isolated from bovine corpora lutea are the focus of this dissertation. A decrease in oxygen consumption and a concomitant decrease in ATP may contribute to luteolysis. These in vitro studies using isolated mitochondria may help to resolve these questions. The first objective was to determine the influence of PGF2a and PGE2 on the oxygen consumption of mitochondria isolated from bovine corpora lutea. The second objective was to determine the effect of both of these prostaglandins on mitochondrial progesterone production. This is the first time that the direct effects of PGF2a on mitochondrial cellular respiration and steroidogenesis have been studied in the corpora lutea of any species. These results will expand information in the area of ovarian physiology and may clarify the roles of PGF2a and PGE2 in corpus luteum function.

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