Inhibition of LH-induced and spontaneous meiotic maturation in mouse oocytes by Nα-tosyl-L-lysine chloromethylketone
✍ Scribed by Hashimoto, Naohiro ;Kishimoto, Takeo ;Nagahama, Yoshitaka
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 648 KB
- Volume
- 247
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
The effect of N alpha-tosyl-L-lysine chloromethylketone (TLCK), an inhibitor of trypsin-type proteases, on luteinizing hormone (LH)-induced and spontaneous meiotic maturation and follicular production of cAMP in mice was determined. When follicle-enclosed mouse oocytes were incubated with LH (1 micron/ml), they underwent the breakdown of the germinal vesicle (GVBD). TLCK (0.02-0.5 mM) inhibited LH-induced GVBD in folliculated oocytes. The concentration (0.5 mM) of TLCK that inhibited LH-induced GVBD did not significantly suppress LH-induced cAMP production by follicle cells. The effect of TLCK on spontaneous maturation in cumulus cell-enclosed and denuded oocytes was also determined. TLCK strongly inhibited spontaneous maturation in denuded oocytes only if it was added to the incubation medium for 1-3 h before oocytes were liberated from the follicular tissue. The inhibition of oocyte maturation by TLCK was significantly greater in cumulus cell-enclosed oocytes than in denuded oocytes, either with or without preincubation with TLCK. These results suggest that trypsin-type protease in oocytes participates in the process of meiotic maturation in mouse oocytes.