| Research Title |
Associations of the bovine follicular health, mitotic activity and intrafollicular amounts of IGFBP-4 on 5 or 6 of the first follicular wave |
| Date of Distribution |
7 August 2010 |
| Conference |
| Title of the Conference |
8th International Ruminant Reproduction Symposium |
| Organiser |
Society of Reproduction in Domestic Ruminants |
| Conference Place |
Hilton Hotel |
| Province/State |
Anchorage |
| Conference Date |
3 August 2010 |
| To |
7 August 2010 |
| Proceeding Paper |
| Volume |
2010 |
| Issue |
67 |
| Page |
123 |
| Editors/edition/publisher |
Nottingham University Press |
| Abstract |
Insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBPs) have been found to play a
crucial role in the selection of bovine dominant follicles. Dominant follicles are characterized by
greater mitotic activity and lower amounts of IGFBP-4 whereas atretic follicles are characterized by
apoptosis of granulosa cells. No associations have yet been made, however, between mitotic activity,
follicular health and intrafollicular amounts of IGFBP-4. The aim of the study, therefore, was to
investigate the interactions of mitotic activity, follicular health and intrafollicular of IGFBP-4. Eight
mature Thai native crossbred beef cows (60±7 mo of age; 461±14 kg BW) received two injections
(11 d apart) of a PGF2a analogue (Estrumate®) to synchronize estrus. Ovaries were collected from
a slaughterhouse on d 5 or 6 of the subsequent estrous cycle. Surface diameter of all follicles > 3
mm was determined. Follicular fluid was gently aspirated and stored at -20°C until determination
of protein and IGFBP-4 by Bradford and Western blot analysis as previously described1. Follicular
health was determined morphologically and classified as previously described2. Mitotic activity of
granulosa and theca cells was evaluated by immmunohistochemistry using a monoclonal PCNA
antibody (Cell Signaling Technology, CA, USA). The labeling index was calculated as the number
of PCNA labeled nuclei expressed as percentage of total nuclei3. A total of 19 healthy and 10 unhealthy
follicles were analyzed. Follicular diameters in healthy follicles were smaller than unhealthy
follicles (6.9±0.7 vs. 9.6±1.5 mm; P<0.01). Regardless of follicular health, labeling index (%) of
granulosa and theca cells were greatest (34.0±3.5 and 29.2±2.3; P<0.05) in small follicles (3 to
6 mm) compared with large follicles (>10 mm; 22.1±2.9 and 19.4±3.3) but were not different
when compared with medium size follicles (7 to 10 mm; 31.7±3.9 and 26.4±3.0). Intrafollicular
amounts of IGFBP-4 quantitated by densitometry were expressed arbitrarily in units. Follicular fluid
amounts of IGFBP-4 were less (P<0.05) in healthy follicles regardless of follicular size. The interaction
of mitotic activity and intrafollicular amounts of IGFBP-4 may play significant roles in follicular
growth and atresia. |
| Author |
|
| Peer Review Status |
มีผู้ประเมินอิสระ |
| Level of Conference |
นานาชาติ |
| Type of Proceeding |
Abstract |
| Type of Presentation |
Oral |
| Part of thesis |
true |
| Presentation awarding |
false |
| Attach file |
|
| Citation |
0
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Publication
Journal Publication
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