Serum and seminal plasma IGF-1 associations with semen variables and effect of IGF-1 supplementation on semen freezing capacity in buffalo bulls

Anim Reprod Sci. 2019 May:204:101-110. doi: 10.1016/j.anireprosci.2019.03.010. Epub 2019 Mar 20.

Abstract

The objective of the study was to establish correlation of seminal and serum IGF-1 with seminal attributes, estimate antioxidant potential of IGF-1 by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and to study the effect of IGF-1 supplementation on semen cryopreservation. For this study, buffalo bulls were divided into sub-fertile (n = 2) and normal (n = 5) on the basis of sperm mass motility and individual motility. The serum IGF-1 concentration of normal bulls was greater than in sub-fertile bulls, but there was no difference in the seminal IGF-1 concentration among the groups. The values from correlation analyses indicated that serum IGF-1 concentration is positively correlated with semen mass motility and sperm concentration. In the second experiment, IGF-1 did not have antioxidant activities when assessed with DPPH and FRAP assays. In the third experiment, the ejaculates of normal and sub-fertile bulls were cryopreserved using semen extender in which there was IGF-1 supplementation at 0 (control), 50, 100, 150, 200, 250, 350 and 450 ng/mL of extender. Supplementation of IGF-1 at 250 ng/ml resulted in improved sperm motility, longevity and membrane intactness as compared to control after cryopreservation of semen from normal buffalo bulls, but not sub-fertile bulls. In summary, serum IGF-1 concentration was correlated with sperm mass motility and concentration in buffalo bulls and supplementation of IGF-1 protected sperm during the cryopreservation process but effects were not due to direct antioxidant activity.

Keywords: Buffalo; Cryopreservation; IGF-1; Semen; Spermatozoa.

MeSH terms

  • Animals
  • Antioxidants / administration & dosage
  • Antioxidants / chemistry
  • Antioxidants / pharmacology
  • Buffaloes*
  • Cryopreservation / veterinary*
  • Dose-Response Relationship, Drug
  • Freezing
  • Insulin-Like Growth Factor I / administration & dosage
  • Insulin-Like Growth Factor I / chemistry
  • Insulin-Like Growth Factor I / pharmacology*
  • Male
  • Semen / chemistry*
  • Semen Preservation / veterinary*
  • Sperm Motility

Substances

  • Antioxidants
  • Insulin-Like Growth Factor I