FSH bioactivity is strongly enhanced by kinetic incubation of pre-antral hamster follicles.
Isolation of meiotic arrested oocytes from mammalian ovaries involves a resumption of the meiosis. Studying the effect of FSH on this process it was found that doses up to of 0.1 IU/ml did not maintain the meiotic arrest in hamster oocytes in pre-antral follicles during static incubation conditions. However, when the FSH medium was replaced at 120, 60 and 30 min the resumption of the meiosis gradually decreased. Using a replacement frequency of 30 min a complete log dose-curve was constructed (ED50: 0.5 mU/ml; minimum effective dose: 0.1 mU/ml). The lack of a FSH response during static incubation was not caused by exhaustion of its bioactivity: mixing of the FSH containing medium, obtained from a 4 hours' static incubation, resulted in an inhibition similar to the inhibition that occurred during the replacement procedure.


CONCLUSIONS
FSH is able to maintain the meiotic arrest in pre-antral follicle enclosed oocytes at low doses only when the medium is in circulation.
Goverde
H J
HJ
Division of Endocrinology & Reproduction (III), Catholic University, Nijmegen, The Netherlands.
van de Venne
W P
WP
D000818:Animals; D001681:Biological Assay / Q000379:methods; D002478:Cells, Cultured; D006224:Cricetinae; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007700:Kinetics; D008540:Meiosis / Q000187:drug effects; D008647:Mesocricetus; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
D003470:Culture Media; D005640:Follicle Stimulating Hormone