Changes of gonadotrophin surge inhibiting/attenuating factor activity in pig follicular fluid in relation to follicle size.
The activity of GnSI/AF was measured in pig follicular fluid (pFF) from 58 individual follicles of various sizes, by bioassay using rat pituitary cells, to investigate the relationship between gonadotrophin surge inhibiting/attenuating factor (GnSI/AF) activity and follicular development. In addition, the correlation between GnSI/AF and inhibin activities and the content of sex steroids (oestradiol, progesterone and testosterone) of follicles was examined. The activity of GnSI/AF in pFF varied significantly (0.155-1.69 U microliter-1) with size of the follicle. The activities (mean +/- SEM) were intermediate and constant in follicles with diameters from 3 to 5 mm (0.583 +/- 0.080 U microliter-1, n = 24), were higher and reached the highest value in follicles with diameters between 6 and 8 mm (0.863 +/- 0.068 U microliter-1, n = 21), and were lower, reaching the lowest value in follicles with diameters of 9 and 10 mm (0.401 +/- 0.089 U microliter-1, n = 13). In contrast, inhibin activity was almost constant during the development of follicles, although individual values varied from 0.9 to 2.5 U microliters-1. For follicles with diameters of 4-8 mm, inhibin activity was 1.754 +/- 0.042 U microliters-1 (n = 39); activity was higher in the smallest follicles with diameters of 3 mm (2.063 +/- 0.015 U microliters-1, n = 6) and was lower in follicles with diameter of 9 mm, reaching the lowest value in follicles with diameter of 10 mm (1.176 +/- 0.068 U microliters-1, n = 7); inhibin activity was not significantly correlated with GnSI/AF activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Kita
M
M
Department of Gynecology and Obstetrics, Faculty of Medicine, Kyoto University, Japan.
Taii
S
S
Kataoka
N
N
Shimatsu
A
A
Nakao
K
K
Mori
T
T
D000818:Animals; D001681:Biological Assay / Q000379:methods; D002478:Cells, Cultured; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D015571:Follicular Fluid / Q000378:metabolism*; D042341:Gonadal Hormones; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000378:metabolism; D007265:Inhibins / Q000378:metabolism; D007986:Luteinizing Hormone / Q000378:metabolism; D006080:Ovarian Follicle / Q000033:anatomy & histology* / Q000502:physiology; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism; D011506:Proteins; D011863:Radioimmunoassay; D051381:Rats; D013552:Swine
D042341:Gonadal Hormones; D011506:Proteins; C080538:attenuin; D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone