著者

Korzekwa Anna J. 奥田 潔 Woclawek-Potocka Izabela 村上 周子 SKARZYNSKI Dariusz J

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.52, no.3, pp.353-361, 2006-06-01

被引用文献数

9 54

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We previously showed in <i>in vivo</i> and <i>in vitro</i> studies that nitric oxide (NO) is engaged in luteolysis in cattle. Nitric oxide produced locally in the bovine corpus luteum (CL) inhibits progesterone (P4) synthesis and is suggested to be a component of the luteolytic cascade induced by uterine prostaglandin (PG) F₂_α. In the present study, the molecular mechanisms of NO action during structural luteolysis were studied in cultured bovine luteal cells (Days 15-17 of the estrous cycle). The effects of the NO donor (NONOate; 10^-4M) on DNA fragmentation, cell viability, P4 production and caspase-3 activity were compared with those of PGF₂_α (10^-6M). Moreover, mobilization of intracellular calcium [Ca²⁺]_i and gene expressions of Fas-L, Fas, bcl-2, bax, and caspase-3 in the cells were determined by semi-quantitative RT-PCR after NONOate treatment. Caspase-3 activity was examined calorimetrically. Contrary to PGF₂_α NONOate decreased cell viability. DNA fragmentation after NONOate treatment increased by more than with PGF2₂_α. NONOate increased mobilization of [Ca²⁺]_i in the cells. Although the NO donor did not affect Fas-L and bcl-2 gene expression, it stimulated Fas and bax mRNA and caspase-3 expression. The ratio of bcl-2 to bax mRNA level decreased in the cells treated with NONOate. Moreover, NONOate stimulated caspase-3 activity more effectively than PGF₂_α. The overall results suggest that NO is a luteolytic factor that plays a crucial role in regulation of the estrous cycle in structural luteolysis by inducing apoptosis of luteal cells in cattle.<br>