Follicular fluid concentrations of free insulin-like growth factor (IGF)-I during follicular development in mares
The objective of the present study was to evaluate changes in concentrations of free insulin-like growth factor (IGF)-I in follicular fluid (FFL) during follicle development in the mare. Mares ( n = 14) were classified as either in the follicular phase ( n = 8) or luteal phase ( n = 6). Follicles (...
Gespeichert in:
Veröffentlicht in: | Domestic animal endocrinology 2005-11, Vol.29 (4), p.573-581 |
---|---|
Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The objective of the present study was to evaluate changes in concentrations of free insulin-like growth factor (IGF)-I in follicular fluid (FFL) during follicle development in the mare. Mares (
n
=
14) were classified as either in the follicular phase (
n
=
8) or luteal phase (
n
=
6). Follicles (
n
=
92) were categorized as small (6–15
mm;
n
=
54), medium (16–25
mm;
n
=
23) or large (>25
mm;
n
=
15) and FFL was collected. Free IGF-I levels in FFL in large follicles of follicular phase mares were greater (
P
<
0.05) than in large follicles of luteal phase mares and small or medium follicles of luteal and follicular phase mares. Free IGF-I concentrations were greater (
P
<
0.05) in large follicles of luteal phase mares than small but not medium follicles of luteal phase mares. FFL ratio of estradiol:progesterone paralleled changes in free IGF-I. Free IGF-I concentrations were negatively correlated (
P
<
0.05) with insulin-like growth factor binding protein (IGFBP)-2, -4 and -5 but not IGFBP-3 levels. In addition, free IGF-I concentrations in FFL were positively correlated (
P
<
0.01) with FFL estradiol, progesterone, androstenedione, estradiol:progesterone ratio, total IGF-I and total IGF-II. We conclude that increases in intrafollicular levels of bioavailable (free) IGF-I are associated with increased steroidogenesis in developing mare follicles. |
---|---|
ISSN: | 0739-7240 1879-0054 |
DOI: | 10.1016/j.domaniend.2005.03.003 |