|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ovary |
Eutheria Foundation, Cross Plains, Wisconsin 53528
Color Doppler transrectal ultrasound was used to evaluate blood flow area in the wall of dominant anovulatory follicles versus ovulatory follicles in mares during the transition between anovulatory and ovulatory seasons. Daily examinations were done in 11 control mares toward the end of the anovulatory season. In 13 separate mares, follicular fluid was collected from 30-mm follicles, and blood flow areas from control mares were used as a basis for designating the sampled follicle as either anovulatory or ovulatory. Blood flow area in the controls ranged from 0.18 to 0.35 cm2 in six mares on the day of a 30-mm anovulatory follicle and from 0.25 to 0.86 cm2 in 11 mares on the day of a 30-mm ovulatory follicle; the ranges did not overlap except for one follicle. In the controls, mean blood flow area was lower (P < 0.05) in the anovulatory group than in the ovulatory group for each day beginning with the first Doppler examination at 25 mm. For plasma LH in controls, an effect of follicle group (P < 0.0001) and an interaction (P < 0.0001) of group by day reflected lower (P < 0.05) concentrations in the anovulatory group on Days 6, 2, and 58 (Day 0 = 30-mm follicle). For plasma FSH, an interaction (P < 0.0001) reflected higher (P < 0.05) concentrations in the anovulatory group on Days 3 and 14. More (P < 0.05) statistically identified FSH surges occurred in the anovulatory group during Days 7 to 8. In the sampled mares, follicular-fluid concentrations of estradiol, free insulin-like growth factor-1, inhibin-A, and vascular endothelial growth factor were lower (P < 0.05) in 30-mm designated anovulatory follicles than in 30-mm designated ovulatory follicles. Results were interpreted as follows: 1) The future anovulatory dominant-sized follicle developed under an LH deficiency, 2) the LH deficiency led to reductions in blood flow area and in concentrations of follicular-fluid factors, and 3) the reduction in follicle production of FSH suppressors resulted in higher plasma FSH concentrations.
2 Correspondence: O.J. Ginther, Department of Animal Health and Biomedical Sciences, 1656 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706. FAX: 608 262 7420; ginther{at}svm.vetmed.wisc.edu
3 Current address: Laboratory of Reproductive Endocrinology, Faculty of Agriculture, Okayama University, Tsushima Naka, Okayama 700-8530, Japan
This article has been cited by other articles:
![]() |
E L Gastal, M O Gastal, and O J Ginther Relationships of changes in B-mode echotexture and colour-Doppler signals in the wall of the preovulatory follicle to changes in systemic oestradiol concentrations and the effects of human chorionic gonadotrophin in mares. Reproduction, April 1, 2006; 131(4): 699 - 709. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |