OBJECTIVEHeavy metals such as cadmium (Cd) are widely distributed in the environment as industrial pollutants and characterized by their ability to affect the male reproductive system. The objective of the present study was to test the effect of Cd in the concentration range from 10 to 1000 micromol/L, in vitro, on the membrane and DNA integrity, motility, and ability of sperm to undergo acrosomal exocytosis in Holstein bull spermatozoa.

METHODSBull semen samples were processed for sperm analyses using semen-diluting fluid, PBS. Membrane integrity of the processed bull sperm was evaluated by lipoperoxidation (LPO) test. Gelatin digestion test was performed to determine the ability of bull spermatozoa to undergo acrosomal exocytosis. Single cell gel electrophoresis (SCGE) assay was performed to detect the DNA strand breaks and alkali labile damages in the individual cell.

RESULTSWe found a significant increase in the lipoperoxidation (LPO) indicating the deleterious effect of Cd on the sperm membrane integrity. This effect was prominent at the concentration of 1000 micromol/L Cd. There was a negative correlation between LPO rate and the percentage of motile spermatozoa (r = -0.94, P < 0.001). The gelatin digestion test indicated that Cd caused a decline in the percentage of acrosomal exocytosis of bull spermatozoa. A reverse correlation was also found between LPO rate and the percentage of halos (r = -0.97, P < 0.001). Data obtained from the comet assay revealed that Cd was capable of inducing DNA breaks in the sperm nuclei. Almost 93% of DNA damages were double-stranded breaks. The correlation between LPO rate and the percentage of DNA breaks was found to be 0.95 (P < 0.001).

CONCLUSIONCollectively, Cd induced membrane impairments, lowered motility, DNA breaks and a decreased rate in the acrosome reaction of bull spermatozoa, leading to sperm dysfunction. Entering Cd in the male gonads and seminal plasma may exert deleterious effects on the animal sperm cells.

Acrosome Reaction ; Animals ; Cadmium ; toxicity ; Cattle ; DNA Breaks ; Lipid Peroxidation ; Male ; Semen ; drug effects ; Sperm Motility

OBJECTIVETobacco smoking is recognized as a general health hazard, and evidence indicates that cigarette smoking affects reproductive health in both men and women. The aim of this study was to provide evidence that cigarette smoking affects male fertility via altering the semen and sperm quality.

METHODSWe evaluated the direct effect of seminal plasma (SP) (in the different dilutions with PBS, 1/0; 1/1; 1/2; 1/6; 1/10) from smokers (SM) on spermatozoa from non-smokers (NSM).

RESULTSExposure of spermatozoa from NSM to the SP from SM yielded an impairment in the membrane integrity by elevation in MDA (Malondialdehyde) levels, a decline in the sperm viability, and a decrease in the number of halos (clear regions around sperm heads due to acrosome reaction on the gelatin slides), in a certain time course.

CONCLUSIONExposure of spermatozoa from the SM to the SP from the NSM resulted in the improvement in sperm dysfunction. It may indicate that removal of smokers SP and then subsequent reconstitution with SP containing sufficient antioxidant systems could be of clinical significance in the various assisted reproductive technologies (ARTs) applied for smokers.

Acrosome Reaction ; physiology ; Adult ; Cell Membrane ; physiology ; Humans ; Male ; Semen ; physiology ; Smoking ; adverse effects ; Sperm Count ; Sperm Motility ; physiology ; Spermatozoa ; physiology

In recent years, the quality of human sperm and its fertility potential have decreased dramatically. This may suggest that the quality of semen has deteriorated partly due to the effects of increasing toxic factors in the environment. Infertility remains a major problem in society, and recent data show that as many as one in four couples is trying to solve the problem. Male infertility accounts for 40% of infertility cases. Many environmental agents such as tobacco smoke and nicotine and genetic factors have been implicated in the poor sperm function and resultant infertility. The article is a review of the impacts of nicotine on human fertility potential. According to our results, nicotine is proved to be a potent pro-oxidant to the biological samples like spermatozoa population and is able to alter the fertility potential of man by inducing the membrane impairments, altering the GSH metabolism cycle, changing the sperm morphology and motility, and also inducing the DNA fragmentation. Antioxidant supplementation could reverse partially the negative effect of nicotine on sperm functions. However, further studies are necessary to illuminate the other dark sides of nicotinic infertility in human spermatozoa.
DNA Damage ; Dose-Response Relationship, Drug ; Fertility ; drug effects ; Glutathione ; metabolism ; Glutathione Peroxidase ; metabolism ; Humans ; Infertility, Male ; chemically induced ; Lipid Peroxidation ; drug effects ; Male ; Nicotine ; adverse effects ; Sperm Motility ; drug effects ; Spermatozoa ; drug effects ; metabolism