The Role of Mercury in the Etiology of Sperm Dysfunction in Holstein Bulls

Abstract

A large number of toxicological substances and pharmacological and physical agents can cause reproductive intervention at the cellular and molecular level. The present study was designed to assess the effect of mercury (HgCl 2 ) at 50 to 550 µM concentration ranges, in vitro, on the sperm membrane and DNA integrity, viability, and acrosomal status of normal bull spermatozoa. The samples were processed for sperm analyses using semen-diluting fluid (PBS, pH 7.2). We recorded a sharp increase in the lipid peroxidation/LPO rate; the highest was at 550 µM mercury concentration, indicating a deleterious effect of mercury on the sperm membrane intactness. There was also a strong negative correlation between LPO rate and % viable spermatozoa (R = 0.987, p<0.001). Data obtained from a comet assay technique revealed that mercury is capable of inducing DNA breaks in the sperm nuclei. Interestingly, 92% of DNA breaks were double-stranded. The correlation between LPO rate and % DNA breaks was 0.984. Performing the gelatin test indicates that mercury is able to alter the integrity of acrosomal membranes showing an abnormal acrosome reaction. In this regard, a strong link was found between LPO rate and % halos (R = 0.990, p<0.001). Collectively, mercury proved to be a potent oxidant in the category of environmental factors affecting bull spermatozoa. Hence, considering the wide spread use of mercury and its compounds, these metals should be regarded with more concern.

Effects of Heavy Metals and Pesticides on Buffalo (Bubalus bubalis) Spermatozoa Functions In Vitro

“…We observed that a concentration of 50 lg ⁄ ml of cadmium significantly decreased spermatozoa motility and is in agreement to the earlier report in cattle (Massanyi et al 1996). In cattle, cadmium at various concentrations ranging from 20 lM (Leoni et al 2002) to 250-300 lM (Arabi 2006;Arabi and Mohammadpour 2006) significantly affected bull sperm motility. This might be owing to differences in sperm processing, incubation time and the method used for examining viability.…”

“…In cattle, cadmium at various concentrations ranging from 20 μ m (Leoni et al. 2002) to 250–300 μ m (Arabi 2006; Arabi and Mohammadpour 2006) significantly affected bull sperm motility. This might be owing to differences in sperm processing, incubation time and the method used for examining viability.…”

“…Incubations were performed in 1 ml final volume (40 million cells/ml) for 1 h at 37°C in an atmosphere of 5% CO 2 and 95% humidity. Incubation was performed for 1 h as has been performed in earlier spermatozoa toxicological studies (Arabi 2006; Arabi and Mohammadpour 2006; Salazar‐Arredondo et al. 2008).…”

“…Incubations were performed in 1 ml final volume (40 million cells ⁄ ml) for 1 h at 37°C in an atmosphere of 5% CO 2 and 95% humidity. Incubation was performed for 1 h as has been performed in earlier spermatozoa toxicological studies (Arabi 2006;Arabi and Mohammadpour 2006;Salazar-Arredondo et al 2008). The spermatozoa functional parameters studied were progressive forward motility, abnormality, plasmalemma integrity, acrosomal integrity, functional membrane integrity, sperm nuclear morphology, mitochondrial membrane potential, nuclear chromatin decondensation (NCD), sperm-zona binding (no.…”

Collapsed mitochondrial cristae in goat spermatozoa due to mercury result in lethality and compromised motility along with altered kinematic patterns

“…Lead, mercury, cadmium, nickel and arsenic have been reported to adversely affect male fertility including fertilizing competence of spermatozoa 1 . In-vivo toxicological studies have shown that heavy metals have the tendency to accumulate in testis and disrupt endocrine and regenerative capacity of testicular cells 2 .…”