title: Inhibition of LH-induced and spontaneous meiotic maturation in mouse oocytes by N alpha-tosyl-L-lysine chloromethylketone.
abstract: 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.
authors.affiliation: Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Hashimoto
authors.forename: T
authors.initials: T
authors.lastname: Kishimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000032:analysis / Q000096:biosynthesis; D005260:Female; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D009924:Organ Culture Techniques; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D011863:Radioimmunoassay; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology*
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D014107:Tosyllysine Chloromethyl Ketone; D007986:Luteinizing Hormone; D000242:Cyclic AMP