Cigarette smoking affects specific sperm oxidative defenses but does not cause oxidative DNA damage in infertile men.
OBJECTIVE
To evaluate the effects of tobacco consumption on the oxidative defenses of sperm, the glutathione system (GS), and sperm DNA oxidation.


METHODS
Double-blind experimental study.


METHODS
Andrology laboratory in a university-affiliated private setting.


METHODS
One hundred seventeen semen samples from infertile males.


METHODS
None.


METHODS
(a) sperm GS enzymatic activity with respect to glutathione peroxidase isoforms GPx-1 and GPx-4, glutathione reductase (GR), and cellular glutathione (GSH) content (n = 29); (b) GPx-1, GPx-4, and GR mRNA expression analysis (n = 33); (c) oxidative DNA damage quantification using OXIDNA assay kit (n = 55). Two groups were established: nonsmoking and smoking males. The t tests were employed to detect significant differences between groups.


RESULTS
We identified a significant decrease in sperm GPx-4 activity but not in GPx-1 and GSH activity in smokers compared with nonsmokers. A significant decrease was also observed in GPx-1, GPx-4, and GR mRNA expression in the former group. Interestingly, we did not observe any significant variation in the percentage of cells with oxidative damage of the DNA or in the average level of oxidation of affected cells with respect to the smoking condition of the male.


CONCLUSIONS
We demonstrate that smoking has a negative impact on intracellular antioxidant enzymes but that effect does not increase oxidative DNA damage. Thus, the effects of reduced oxidative defenses in sperm as a result of cigarette smoking are yet to be elucidated.
Viloria
Thamara
T
IVI Valencia, Universidad de Valencia, Valencia, Spain. tviloria@ivi.es
Meseguer
Marcos
M
Martínez-Conejero
José Antonio
JA
O'Connor
J E
JE
Remohí
José
J
Pellicer
Antonio
A
Garrido
Nicolás
N
D004249:DNA Damage / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D012333:RNA, Messenger / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects*; D013094:Spermatozoa / Q000378:metabolism* / Q000473:pathology; D000094765:Glutathione Peroxidase GPX1
D012333:RNA, Messenger; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human