Impact of induced levels of specific free radicals and malondialdehyde on chicken semen quality and fertility.
Over the past decades, scientists endeavored to comprehend oxidative stress in poultry spermatozoa and its relationship with fertilizing ability, lipid peroxidation (LPO), free-radical scavenging systems, and antioxidant therapy. Although considerable progress has been made, further improvement is needed in understanding how specific reactive oxygen species (ROS) and malondialdehyde (MDA, a toxic byproduct of LPO) disrupt organelles in avian spermatozoon. Hence, this study examined functional changes in chicken spermatozoa after incubation with different ROS, and their implications for the fertility. First, semen samples from 14 roosters were individually diluted and aliquoted into five equal parts: control, superoxide anion, hydrogen peroxide (H2O2), hydroxyl radicals, and MDA. After incubation with these molecules, aliquots were analyzed for motility, plasma membrane and acrosome integrity, mitochondrial activity, and LPO and DNA damage. Hydrogen peroxide was more detrimental for sperm motility than hydroxyl radicals, whereas the superoxide anion and MDA exhibited no differences compared with controls. In turn, plasma membrane and acrosome integrity, mitochondrial activity, LPO and DNA integrity rates were only affected by hydroxyl radicals. Thereafter, semen aliquots were incubated under the same conditions and used for artificial insemination. In accordance to our in vitro observations, H2O2and hydroxyl radicals sharply reduced egg fertility, whereas superoxide anion and MDA only induced slight declines. Thus, chicken sperm function was severely impaired by H2O2and hydroxyl radicals, but their mechanisms of action seemingly comprise different pathways. Further analysis regarding susceptibility of spermatozoon organelles to specific radicals in other poultry will help us to understand the development of interspecific differences in scavenging systems and to outline more oriented antioxidant approaches.
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Bruno R
BR
Rui
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Fábio Y
FY
Shibuya
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Allison J T
AJT
Kawaoku
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
João D A
JDA
Losano
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Daniel S R
DSR
Angrimani
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Andressa
A
Dalmazzo
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil.
Marcilio
M
Nichi
Department of Animal Reproduction, College of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, SP, Brazil. Electronic address: ricpereira@usp.br.
Ricardo J G
RJG
Pereira
D000177:Acrosome / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens / Q000502:physiology*; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro; D005609:Free Radicals / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism*
D005609:Free Radicals; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D006861:Hydrogen Peroxide
Avian spermatozoa; Oxidative stress; Poultry; Reactive oxygen species; Reproduction