Effects of nitric oxide synthase inhibitors on porcine oocyte meiotic maturation.
As an important biological messenger, nitric oxide (NO) exhibits a wide range of effects during physiological and pathophysiological processes, including mammalian oocyte meiotic maturation. The present study investigated whether NO derived from two nitric oxide synthase (NOS) isoforms, inducible NOS (iNOS) or endothelial NOS (eNOS), is involved in the meiotic maturation of porcine oocytes. Meanwhile, the cumulus cells' function in meiotic maturation and their interaction with oocyte development and degeneration were also investigated using cumulus-enclosed oocytes (CEOs) and denuded oocytes (DOs). Different inhibitors for NOS were supplemented to the medium. Cumulus expansion, cumulus cell DNA fragmentation and oocyte meiotic resumption were evaluated 48 h after incubation. Aminoguanidine (AG), a selective inhibitor for iNOS, suppressed cumulus expansion and inhibited CEOs to resume meiosis (p < 0.05), but did not inhibit cumulus cell DNA fragmentation. Both Nomega-nitro-L-arginine (L-NNA) and Nomega-nitro-L-arginine methyl ester (L-NAME), inhibitors for both iNOS and eNOS, delayed cumulus expansion, inhibited cumulus cell DNA fragmentation and inhibited CEOs to resume meiosis. Such effects were not seen in DOs. These results indicate that iNOS-derived NO is necessary for cumulus expansion and meiotic maturation by mediating the function of the surrounding cumulus cells, and eNOS-derived NO is also involved in porcine meiotic maturation.
College of Biological Sciences, China Agricultural University, Beijing and Anhui Agricultural University, Anhui, China.
Yong
Y
Tao
Huirong
H
Xie
Haiyan
H
Hong
Xiufen
X
Chen
Jie
J
Jang
Guoliang
G
Xia
D000818:Animals; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006146:Guanidines / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D019335:Nitroarginine / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects; D013552:Swine
D004791:Enzyme Inhibitors; D006146:Guanidines; D019335:Nitroarginine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C004479:pimagedine; D019331:NG-Nitroarginine Methyl Ester