Chorionic gonadotropin secretion is associated with an inhibition of follicular growth and an improvement in oocyte competence for in vitro maturation in the mare
This study reports the follicular growth and oocyte competence for in vitro maturation and fertilization under the influence of circulating eCG. Three to 7 successive ultrasound-guided follicular punctures were performed on 4 pregnant mares from Day 23 until Day 75 of pregnancy and on 5 control mare...
Saved in:
Published in | Biology of reproduction Vol. 58; no. 3; pp. 760 - 768 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Madison, WI
Society for the Study of Reproduction
01.03.1998
Society for the Study of Reproduction - Oxford Academic |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | This study reports the follicular growth and oocyte competence for in vitro maturation and fertilization under the influence
of circulating eCG. Three to 7 successive ultrasound-guided follicular punctures were performed on 4 pregnant mares from Day
23 until Day 75 of pregnancy and on 5 control mares whose embryonic vesicle was crushed on Day 22. All follicles larger than
5 mm were punctured 24 h after the largest follicle reached 18 mm. Expanded cumulus oocyte complexes (COCs) were stained at
recovery to analyze the nuclear stage. Compact COCs were cultured in vitro for 46 h and either stained or processed for in
vitro fertilization (IVF) and stained 26 h after IVF. In the control group, no mares showed an increase in eCG levels, whereas
all the pregnant mares had concentrations higher than 100 ng/ml from Day 37. The number of follicles flushed during each puncture
attempt significantly decreased with time for 3 of 4 pregnant mares. No significant change in this number was observed for
the 5 control mares. The maturation rate of the oocytes from follicles 10-14 mm was significantly higher in the pregnant vs.
the control group (14 of 17, 82%, vs. 13 of 30, 43%). The difference was not significant for the oocytes from follicles smaller
than 9 mm or larger than 15 mm. After IVF, no oocyte was fertilized. The results led us to conclude that eCG is associated
with an inhibition of follicular growth and an improvement in oocyte competence for in vitro maturation. |
---|---|
Bibliography: | L53 1997067505 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-3363 1529-7268 |
DOI: | 10.1095/biolreprod58.3.760 |