|
|
||||||||
Biology of Reproduction, Vol 57, 278-285, Copyright © 1997 by Society for the Study of Reproduction
ARTICLES |
PA Fowler and CA Price
Department of Obstetrics & Gynaecology, University of Aberdeen, Scotland, United Kingdom. p.a.fowler@abdn.ac.uk
This study aimed to determine whether superovulation in cattle stimulates gonadotropin surge-attenuating/inhibiting factor (GnSAF/IF) bioactivity, as it does in humans. Blood samples were collected from cows (n = 7 per treatment) at -4, 8, 20, 32, 44, 56, and 68 h after injections of saline, eCG, or FSH. Equal volumes of plasma at each treatment and time point were pooled, and GnSAF/IF and inhibin bioactivities were measured using an established rat pituitary cell culture bioassay. Plasma from saline- and eCG-treated cows had little effect on GnRH-induced LH secretion (116.3 +/- 8.3%-81.6 +/- 6.0% of control), while plasma from FSH-treated cows produced a time-dependent suppression of GnRH-induced LH secretion, falling to 64.6 +/- 4.0% of the control value at 56 h after first FSH injection (p < 0.001). The GnSAF/IF bioactivity from the 56-h plasma eluted at pH 5.73 by pseudochromatofocusing-similar to the GnSAF/IF isoelectric point value of 5.81 determined using serum from superovulated women. Plasma from FSH-treated cows reduced basal FSH secretion more than plasma from eCG- treated cows (to 55.5 +/- 5.7% and 63.2 +/- 6.6% of the control value, respectively, p < 0.01) although immunoreactive inhibin concentrations were similar between the two groups. We conclude that FSH, but not eCG, treatment causes a time-dependent production of circulating GnSAF/IF bioactivity in cattle.
This article has been cited by other articles:
![]() |
E. Karligiotou, P. Kollia, A. Kallitsaris, and I.E. Messinis Expression of human serum albumin (HSA) mRNA in human granulosa cells: potential correlation of the 95 amino acid long carboxyl terminal of HSA to gonadotrophin surge-attenuating factor Hum. Reprod., March 1, 2006; 21(3): 645 - 650. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A Fowler and N. Spears The cultured rodent follicle as a model for investigations of gonadotrophin surge-attenuating factor (GnSAF) production Reproduction, June 1, 2004; 127(6): 679 - 688. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Fowler, T. Sorsa-Leslie, P. Cash, B. Dunbar, W. Melvin, Y. Wilson, H. D. Mason, and W. Harris A 60-66 kDa protein with gonadotrophin surge attenuating factor bioactivity is produced by human ovarian granulosa cells Mol. Hum. Reprod., September 1, 2002; 8(9): 823 - 832. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |