Endocrinology, Vol 133, 491-495, Copyright © 1993 by Endocrine Society

ARTICLES

Plasma membrane changes in the rat corpus luteum induced by oxygen radical generation

X Wu, K Yao and JC Carlson
Department of Biology, University of Waterloo, Ontario, Canada.

The luteolytic mechanism was investigated in rat corpora lutea (CL). This study focused on the changes that occur in the plasma membrane. Previous experiments with rat luteal cells indicated that in vitro generation of superoxide radicals by xanthine oxidase disrupted LH- stimulated cAMP production and progesterone secretion similar to the effect of prostaglandin F2 alpha, the luteolytic hormone. In the present study, we observed that xanthine oxidase treatment of plasma membrane samples from CL caused a large decrease in fluidity, which also occurs during prostaglandin F2 alpha-induced luteolysis. This fluidity change was blocked by catalase, bromophenacyl bromide, an inhibitor of phospholipase-A activity, indomethacin, and free radical scavengers, and it was reversed by removal of FFA from the membrane. In addition, xanthine oxidase treatment caused phospholipid breakdown, formation of neutral lipids, a burst of inorganic peroxides, and a sustained rise in the level of lipid peroxides. These results indicate that free radical generation causes several changes that disrupt the plasma membrane of CL cells, and they raise the possibility that phospholipid breakdown could be involved in the mechanism that inhibits LH stimulation of steroidogenesis during luteolysis.

This article has been cited by other articles:

				L. Luo, H. Chen, and B. R. Zirkin Temporal Relationships Among Testosterone Production, Steroidogenic Acute Regulatory Protein (StAR), and P450 Side-Chain Cleavage Enzyme (P450scc) During Leydig Cell Aging J Androl, January 1, 2005; 26(1): 25 - 31. [Abstract] [Full Text] [PDF]

				H. Chen, J. Liu, L. Luo, and B. R. Zirkin Dibutyryl Cyclic Adenosine Monophosphate Restores the Ability of Aged Leydig Cells to Produce Testosterone at the High Levels Characteristic of Young Cells Endocrinology, October 1, 2004; 145(10): 4441 - 4446. [Abstract] [Full Text] [PDF]

				J. R. Pepperell, D. M. Porterfield, D. L. Keefe, H. R. Behrman, and P. J. S. Smith Control of ascorbic acid efflux in rat luteal cells: role of intracellular calcium and oxygen radicals Am J Physiol Cell Physiol, September 1, 2003; 285(3): C642 - C651. [Abstract] [Full Text] [PDF]

				H. Chen, M. P. Hardy, and B. R. Zirkin Age-Related Decreases in Leydig Cell Testosterone Production Are Not Restored by Exposure to LH in Vitro Endocrinology, May 1, 2002; 143(5): 1637 - 1642. [Abstract] [Full Text] [PDF]

				S. Takiguchi, N. Sugino, S. Kashida, Y. Yamagata, Y. Nakamura, and H. Kato Rescue of the Corpus Luteum and an Increase in Luteal Superoxide Dismutase Expression Induced by Placental Luteotropins in the Rat: Action of Testosterone Without Conversion to Estrogen Biol Reprod, February 1, 2000; 62(2): 398 - 403. [Abstract] [Full Text]

				N. Sugino, S. Takiguchi, S. Kashida, H. Takayama, Y. Yamagata, Y. Nakamura, and H. Kato Suppression of Intracellular Superoxide Dismutase Activity by Antisense Oligonucleotides Causes Inhibition of Progesterone Production by Rat Luteal Cells Biol Reprod, October 1, 1999; 61(4): 1133 - 1138. [Abstract] [Full Text]

				J. A. McCracken, E. E. Custer, and J. C. Lamsa Luteolysis: A Neuroendocrine-Mediated Event Physiol Rev, April 1, 1999; 79(2): 263 - 323. [Abstract] [Full Text] [PDF]