Role of prostaglandin in the control of ovulation in the Japaneseeel Anguilla japonica
The in vitro effects of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and prostaglandins (PGE1, PGE2, PGF1α,PGF2α) on ovulation in the Japanese eel Anguillajaponica were examined. Oocytes with follicle layers at themigratory nucleus stage (approximately 850–900 µmdiameter) were removed using a polyethylene cannula from artificiallymatured fish. At concentrations of 10 and 100 ng/mL,DHP was found to induce both germinal vesicle breakdown and ovulation.The prostaglandins, except for PGE1, effectively inducedovulation of previously matured oocytes by DHP treatment in vitro.Prostaglandin F2α was the most effective. Asignificant increase in ovulation rate was observed even at a concentrationof 0.01 µg/mL PGF2α.Indomethacin blocked the in vitro ovulation induced by DHPand addition of PGF2α reversed indomethacin-blockedovulation. Actinomycin D and cycloheximide blocked DHP-induced ovulationand PGF2α reversed the effects of both inhibitors. Theseresults indicate that DHP induces ovulation through endogenous prostaglandinsynthesis in the follicle layers of the Japanese eel.
Document Type: Research Article
Affiliations: 1: National Research Instituteof Aquaculture, Fisheries Research Agency, Nansei, Mie 516-0193and 2: Inland Station, National ResearchInstitute of Aquaculture, Fisheries Research Agency, Tamaki, Mie 519-0423, Japan
Publication date: 2003-04-01