Skip to main content
ARS Home » Southeast Area » Little Rock, Arkansas » Arkansas Children's Nutrition Center » Research » Publications at this Location » Publication #151496
Title: INSULIN-LIKE GROWTH FACTOR-I AND INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-2 AND -5 IN EQUINE SEMINAL PLASMA: ASSOCIATION WITH SPERM CHARACTERISTICS AND FERTILITY

Author
item MACPHERSON, M - UNIV/FLORIDA
item SIMMEN, ROSALIA - UAMS
item SIMMEN, FRANK - UAMS
item HERNANDEZ, J - UNIV/FLORIDA
item SHEERIN, B - UNIV/FLORIDA
item VARNER, D - UNIV/FLORIDA
item LOOMIS, P - TEXAS A&M UNIV
item CADARIO, M - SELECT BREEDER SERV INC
item MILLER, C - SELECT BREEDER SERV INC
item BRINSKO, S - UNIV/FLORIDA
item RIGBY, S - UNIV/FLORIDA
item BLANCHARD, T - UNIV/FLROIDA

Submitted to: Biology of Reproduction
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2002
Publication Date: 8/15/2002
Citation: MACPHERSON, M.L., SIMMEN, R., SIMMEN, F.A., HERNANDEZ, J., SHEERIN, B.R., VARNER, D.D., LOOMIS, P., CADARIO, M.E., MILLER, C.D., BRINSKO, S.P., RIGBY, S., BLANCHARD, T.L. INSULIN-LIKE GROWTH FACTOR-I AND INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-2 AND -5 IN EQUINE SEMINAL PLASMA: ASSOCIATION WITH SPERM CHARACTERISTICS AND FERTILITY. BIOLOGY OF REPRODUCTION. 2002. v. 67. p. 648-654.

Interpretive Summary: We studied semen from stallions that were being used for breeding of mares and semen from animals that were not currently being used for breeding purposes. Our goal was to identify what was different in the protein composition of the semen from different stallions and that might be associated with increased reproductive success of particular stud animals. We identified a positive association of breeding success of stallions with the presence of a particular protein, named IGF-I, within the semen. We believe that this protein may help in making healthier sperm. This is particularly interesting since IGF-I is known to be a protein whose levels in the body is under nutritional control.

Technical Abstract: The objectives of this study were 1) to determine whether insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) were present in seminal plasma of stallions; 2) to compare semen parameters (IGF proteins, sperm numbers, morphology, and motility) from stallions at sexual rest (SR) and when sexually active (SA); 3) to compare semen parameters between stallions with high and low seminal plasma IGF-I concentrations; and 4) to examine the relationship between seminal plasma IGF-I concentrations and fertility parameters of stallions. Ejaculates were collected from stallions at SR (n = 51) and SA (n = 46). Concentrations of IGF-I and IGFBP-2 in seminal plasma samples were determined by radioimmunoassay. Presence of IGFBPs in equine seminal plasma was verified using immunoprecipitation and Western ligand blot procedures. IGF-I, IGFBP-2, and IGFBP-5 were present in equine seminal plasma. Concentrations of IGF-I, IGF-I/protein, total IGF-I, IGFBP-2, IGFBP-2/protein, and total IGFBP-2 were not significantly different (P > or = 0.13) in seminal plasma between stallions at either SR or SA. At SR, stallions with higher seminal plasma IGF-I had more total IGFBP-2 per ejaculate (P < 0.01), more morphologically normal sperm (P = 0.05), and higher first-cycle pregnancy rates (P = 0.02). At SA, stallions with higher seminal plasma IGF-I had fewer cycles per pregnancy (P = 0.02). An association of seminal plasma IGF-I concentration with sperm motility, sperm morphology, and pregnancy rates in bred mares suggests that IGF-I may play a role in sperm function.