| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Regular Article |
a Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853
ABSTRACT
Low molecular weight insulin-like growth factor binding proteins (IGFBPs), particularly IGFBP-4, are believed to inhibit the actions of insulin-like growth factors (IGFs). We showed previously that ovarian follicular dominance in cattle is associated with the presence of a protease that degrades IGFBP-4. To test the hypothesis that specific IGFBP-4 proteolysis is associated with selection of the dominant follicle, we induced codominant follicles (co-DFs) during the first follicular wave of the estrous cycle. The ovaries of Holstein heifers were examined twice daily by ultrasonography; when the largest follicle reached 6 mm in diameter, saline (control, n = 5) or 2 mg of recombinant bovine (rb) FSH (FSH, n = 5) was injected i.m. every 12 h for 48 h. Follicular fluid was collected by aspiration from the two largest follicles/heifer 12 h after the last injection. IGFBPs in follicular fluid were quantified by Western ligand blotting/phosphorimaging. IGFBP-4 protease activity was measured by incubating follicular fluid with recombinant human (rh) IGFBP-4 substrate, followed by ligand blotting/phosphorimaging to quantify the percent of substrate loss and Western immunoblotting to detect specific proteolytic fragments. Co-DFs of FSH heifers did not differ (P > 0.05) from the single dominant follicle of controls in size, or in concentration of progesterone or level of IGFBP-4 in follicular fluid. In contrast, the largest subordinate follicle of control heifers was smaller, with lower progesterone and higher IGFBP-4 in the follicular fluid (P < 0.05). Concentrations of estradiol in follicular fluid were high in dominant follicles, intermediate in co-DFs, and low in subordinate follicles (P < 0.05). IGFBP-4 protease activity in co-DFs was similar (P > 0.05) to that of dominant follicles, but fourfold higher (P < 0.05) than that of subordinate follicles. The results strongly suggest that an FSH-dependent IGFBP-4 protease is associated with selection of the dominant follicle in cattle.
First decision: 13 November 2000.
1 Supported by National Institutes of Health grant HD38276 to J.E.F. and a Fulbright-Universidad Nacional de Río Cuarto (Argentina) Fellowship to G.M.R.
2 Correspondence. FAX: 607 253 3476; jf11{at}cornell.edu
This article has been cited by other articles:
|
|
 |
|
  H. Lopez, R. Sartori, and M. C. Wiltbank Reproductive Hormones and Follicular Growth During Development of One or Multiple Dominant Follicles in Cattle Biol Reprod, April 1, 2005; 72(4): 788 - 795. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Matsui, B. Sonntag, S. S. Hwang, T. Byerly, A. Hourvitz, E. Y. Adashi, S. Shimasaki, and G. F. Erickson Pregnancy-Associated Plasma Protein-A Production in Rat Granulosa Cells: Stimulation by Follicle-Stimulating Hormone and Inhibition by the Oocyte-Derived Bone Morphogenetic Protein-15 Endocrinology, August 1, 2004; 145(8): 3686 - 3695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. J. Spicer Proteolytic Degradation of Insulin-Like Growth Factor Binding Proteins by Ovarian Follicles: A Control Mechanism for Selection of Dominant Follicles Biol Reprod, May 1, 2004; 70(5): 1223 - 1230. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Quirk, R. G. Cowan, R. M. Harman, C.-L. Hu, and D. A. Porter Ovarian follicular growth and atresia: The relationship between cell proliferation and survival J Anim Sci, January 1, 2004; 82(13_suppl): E40 - 52. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Sisco, L. J. Hagemann, A. N. Shelling, and P. L. Pfeffer Isolation of Genes Differentially Expressed in Dominant and Subordinate Bovine Follicles Endocrinology, September 1, 2003; 144(9): 3904 - 3913. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. M. Rivera and J. E. Fortune Proteolysis of Insulin-Like Growth Factor Binding Proteins -4 and -5 in Bovine Follicular Fluid: Implications for Ovarian Follicular Selection and Dominance Endocrinology, July 1, 2003; 144(7): 2977 - 2987. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. M. Rivera and J. E. Fortune Selection of the Dominant Follicle and Insulin-Like Growth Factor (IGF)-Binding Proteins: Evidence that Pregnancy-Associated Plasma Protein A Contributes to Proteolysis of IGF-Binding Protein 5 in Bovine Follicular Fluid Endocrinology, February 1, 2003; 144(2): 437 - 446. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Monget, S. Mazerbourg, T. Delpuech, M.-C. Maurel, S. Maniere, J. Zapf, G. Lalmanach, C. Oxvig, and M. T. Overgaard Pregnancy-Associated Plasma Protein-A Is Involved in Insulin-Like Growth Factor Binding Protein-2 (IGFBP-2) Proteolytic Degradation in Bovine and Porcine Preovulatory Follicles: Identification of Cleavage Site and Characterization of IGFBP-2 Degradation Biol Reprod, January 1, 2003; 68(1): 77 - 86. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Spears, S. Baker, V. Srsen, R. Lapping, J. Mullan, R. Nelson, and V. Allison Mouse Ovarian Follicles Secrete Factors Affecting the Growth and Development of Like-Sized Ovarian Follicles In Vitro Biol Reprod, December 1, 2002; 67(6): 1726 - 1733. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Mazerbourg, M. T. Overgaard, C. Oxvig, M. Christiansen, C. A. Conover, I. Laurendeau, M. Vidaud, G. Tosser-Klopp, J. Zapf, and P. Monget Pregnancy-Associated Plasma Protein-A (PAPP-A) in Ovine, Bovine, Porcine, and Equine Ovarian Follicles: Involvement in IGF Binding Protein-4 Proteolytic Degradation and mRNA Expression During Follicular Development Endocrinology, December 1, 2001; 142(12): 5243 - 5253. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.M. Rivera, Y.A. Chandrasekher, A.C.O. Evans, L.C. Giudice, and J.E. Fortune A Potential Role for Insulin-Like Growth Factor Binding Protein-4 Proteolysis in the Establishment of Ovarian Follicular Dominance in Cattle Biol Reprod, July 1, 2001; 65(1): 102 - 111. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
