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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVE NUTRIENT MANAGEMENT AND EFFICIENCY IN CATTLE Title: Vascular Endothelial Growth Factor (VEGF) mRNA Isoforms are Altered in Bovine Granulosa Cells (GC) by Circulating Progestin Concentrations (P4) and May Indicate Follicle Status and Oocyte Competence

Authors
item Slattery, Racheal - UNIV NEBRASKA, LINCOLN
item Clopton, Debra - UNIV NEBRASKA, LINCOLN
item Wood, Jennifer - UNIV NEBRASKA, LINCOLN
item Cushman, Robert
item Cupp, Andrea - UNIV NEBRASKA, LINCOLN

Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: November 12, 2008
Publication Date: July 1, 2009
Citation: Slattery, R., Clopton, D., Wood, J., Cushman, R., Cupp, A. 2009. Vascular Endothelial Growth Factor (VEGF) mRNA Isoforms are Altered in Bovine Granulosa Cells (GC) by Circulating Progestin Concentrations (P4) and May Indicate Follicle Status and Oocyte Competence [abstract]. Journal of Animal Science. 87 (E-Supplement 3):66 (Abstract # 85).

Technical Abstract: Previously, Melengestrol Acetate (MGA) fed for 14 d (0.5mg/cow/d; < 1 ng/ml P4) resulted in persistent follicles with increased size, decreased number of GC/follicular fluid (FF) volume, and less fertile oocytes. An experiment was conducted to determine effects of circulating P4 on amount of mRNA for pro- and anti-angiogenic vascular endothelial growth factor (VEGF) isoforms in GC of dominant (largest estrogen active; DOM) and subordinate (next largest; SUB) follicles. The hypothesis tested was that DOM developed with MGA will have reduced VEGF proto anti-angiogenic mRNA isoforms in GC compared to controlled intravaginal drug releasing device (CIDR) (control; 4-6 ng/ml of P4). Cows (n = 13) received prostaglandin F2a (PG) on d 1 and 7 and MGA for 14 d or GnRH on d 7 and a CIDR for 7 d (n = 14). On d 14, all cows received PG and CIDR’s were removed. Ovariectomies were conducted 36 h post-PG and GC, FF and blood was collected for analysis. Data were analyzed using PROC MIXED of SAS with mean separation by LSD. MGA DOM (n = 13) were larger (P < 0.001) and had decreased GC:FF ratio (P = 0.06); but, E2: P4 ratio did not differ from CIDR DOM (n = 14). Increased E2 was present in DOM (P < 0.001) compared to SUB (n = 16; 1047.6 ± 137 vs. n = 14; 161.4 ± 140 ng/ml) and P4 was greater (P = .001) in SUB compared to DOM (n = 14; 259.0 ± 44 vs. n = 16; 42.2 ± 43 ng/ml). Angiogenic VEGF164 isoform mRNA tended (P = 0.10) to be increased in DOM compared to SUB. In addition, VEGF165b isoform was greater (P = 0.05) in SUB compared to DOM (n = 14; 10.7 ± 3 vs. n = 16; 2.5 ± 3). Furthermore, VEGF164:VEGF165b mRNA isoform ratio was greater in DOM (n = 16; 1.1 ± 0.2 vs. n = 14; 0.4 ± 0.2; P < 0.05) vs. SUB. CIDR DOM (n = 14) tended (P = 0.08) to have a greater VEGF164:VEGF165b ratio than MGA DOM (n = 12). From these results, VEGF pro- to anti-angiogenic isoform ratio is greater in GC from healthy, estrogenic (dominant), nonpersistent follicles suggesting that ratio of VEGF mRNA isoforms is a good indicator of follicle status and oocyte competence.

Last Modified: 7/22/2014
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