BackgroundHumans are ubiquitously exposed to multiple environmental contaminants. Consequences of combined action on the reproductive system remain unknown. This study aimed to assess single and joint effects of cadmium and diazinon exposure on sperm quality parameters.MethodsMale adult Wistar rats were randomized into 4 groups of ten animals each. Group A was used as a control, animals from group B were exposed to cadmium (30 mg/L), rats from group C were administered with diazinon (40 mg/L), and rats from group D were exposed simultaneously to cadmium (30 mg/L) and diazinon (40 mg/L) via drinking water for 90 days. Sperm morphology and motility were evaluated using a bright field microscope and a computer-assisted semen analysis.ResultsThe percentage of motile spermatozoa and morphologically normal sperm was markedly reduced in rats from the group B. Rats from the C group showed an increase in velocity parameters, amplitude of lateral head displacement, decrease in beat-cross frequency, and an increase in abnormal sperm morphology. Simultaneous coexposure to cadmium and diazinon increased distance and velocity parameters, and amplitude of lateral head displacement. Reductions were observed in straightness, linearity, wobble, and beat-cross frequency. The decreased normal sperm morphology rates were related to defects of the sperm tail.ConclusionsExposure to cadmium and diazinon at relatively low doses impairs sperm quality and can reduce male fertility. Cadmium and diazinon caused significant changes on sperm morphology with varying effects on motility patterns. These parameters were significantly higher in the group D as compared to the group C. The findings have important implications for reproductive risk assessment of combined exposures to multiple chemicals.

This study was conducted to investigate the effect of heat stress (i.e., elevated ambient temperature -Ta; 36 °C ± 3 °C) on growth performance, mortality rate, and on some haematological and biochemical parameters in different categories of gender and age of New Zealand White (NZW) rabbits. Animals were divided into two main groups (control and treatment), in each group there were 56 rabbits: adult females (n = 20), adult males (n = 4), growing females (n = 16), and growing males (n = 16). Results revealed that total and daily feed intake, feed conversion ratio, and total and daily gain in body weight for growing NZW rabbits were affected negatively by elevated Ta. Decreases in feed intake led to less protein biosyntheses and less fat deposition, which led to lower body weight gain. These observations were made in growing and adult rabbits of both genders. Analysis showed that red blood cell (RBC) counts showed alterations. Packed cell volume (PCV) (in adult females and males), white blood cell (WBC) counts (in growing females), lymphocytes (in growing males), monocytes (in growing females and adult males), basophils (in growing females and growing and adult males) were significantly (P < 0.05) decreased, and total proteins (TP) (in adult females), glucose (Glu) (in adult females), and calcium (Ca 2+ ) (in growing males and females) were significantly (P < 0.01) lower in the experimental group. Furthermore, elevated Ta increased the mortality rate (MR) in both age groups. The mortality rate was 30.36% for growing and adult rabbits of the experimental group, compared with 7.14% for the control group, and was 25% for adult compared with 34.38% for growing experimental rabbits. Exposure of NZW rabbits of both ages and genders to elevated ambient temperature (36°C ± 3 °C), negatively affected their internal homeostasis which was reflected in their growth rate and various physiological signs.

Effects of a 50 Hz extra-low frequency electromagnetic field (ELF EMF) on in vitro rabbit spermatozoa motility were analyzed, as well as the effect on fertilization rates after insemination. Pooled semen samples and a control were exposed to 50 Hz ELF EMF. The difference of the samples of the test groups G1 and G2 with the control group CG (75.56%) for spermatozoa motility were found to be significant (P < 0.01). Differences were significant (P < 0.01) for curvilinear velocity (VCL) between the test group G3 (122.38 microm/s) and the control group CG (112.02 microm/s). Hormonally stimulated adult (9-12 months) females (n = 140) were inseminated with semen samples from G1, G2, G3 and CG (0.88 x 109 spermatozoa/0.5 mL average insemination portion) immediately after ELF EMF exposure and fertilization (kindling) rates were calculated. For the G2 it was 54.28% data indicate 50 Hz ELF EMF induced alterations of spermatozoa motility and kindling rate in rabbits, therefore influencing fertility.

In this study effects of mercury administration on the kidney and testicular structure of adult rats were evaluated. Rats received mercury (HgCl2) in single intraperitoneal dose 20 mg HgCl2 (group A), 10 mg HgCl2 (group B) and 5 mg HgCl2 (group C) per kilogram of body weight and were killed after 48 hours following mercury administration. After the preparation of histological samples the results were compared with control group (K). In kidney decreased diameters of glomeruli and renal corpuscles, damaged tubules with affected quality of tubular cells and infiltration of interstitium were detected. Quantitative analysis demonstrated increased relative volume of tubules and renal corpuscles. Also the number of nuclei and glomeruli was increased in all experimental groups. The diameter of glomeruli and renal corpuscles was decreased. In testis undulation of basal membrane, dilatation of blood vessels in interstitium and occurrence of empty spaces in germinal epithelium were observed. Decreased relative volume of germinal epithelium, increased relative volume of interstitium and increased apoptosis occurrence suggest damaged interstitium and revealed occurrence of edemas. The relative volume of seminiferous tubules showed higher luminization. The number of nuclei was decreased in all experimental groups what is in positive relation with occurrence of empty spaces. Also other evaluated criteria demonstrated significant differences between control group and experimental groups. This study reports a negative effect of mercury on the structure and function of kidney and testes.

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In this study the concentrations of trace elements such as lead, cadmium, iron, nickel, copper and zinc in the human semen (n = 47), occurrence of pathological spermatozoa, and correlations of these elements to pathological forms were investigated. For each sample of human spermatozoa at least 500 spermatozoa were evaluated. Metal contents were determined by the voltametric method and flame absorption spectrophotometry method. The concentrations of trace elements in human semen were: lead 1.49 +/- 0.40 mg x kg(- 1), cadmium 0.13 +/- 0.15 mg x kg(- 1), iron 2.59 +/- 0.21 mg x kg(- 1), nickel 0.40 +/- 0.07 mg x kg(- 1), copper 0.28 +/- 0.06 mg x kg(- 1), and zinc 153.93 +/- 67.08 mg x kg(- 1), respectively. The total percentage of pathological spermatozoa was 41.61 +/- 9.80% with predominancy of broken flagellum, flagellum torso and separated flagellum. In relation to trace elements the analysis showed correlation between copper and lead (r = -0.47), nickel and iron (r = 0.36), lead and flagellum ball (r = -0.39), cadmium and large heads (r = 0.37) and between iron and other forms of pathological spermatozoa (r = -0.32). Results of this study describe possible effects of trace elements on the spermatozoa quality in normal human sperm.

The aim of this study was to monitor accumulation of lead, cadmium, mercury and arsenic in leg skeletal muscle of some wild birds from selected areas of Slovakia and the correlations among the heavy metals. A total of 160 wild birds representing 3 species-Eurasian coot (Fulica atra) (n = 24), mallard (Anas platyrhynchos) (n = 68) and pheasant (Phasianus colchicus) (n = 68) were involved for analyses. Concentrations of heavy metals from samples were measured using atomic absorption spectrophotometry (AAS). Metal concentrations are expressed as mg/kg wet weight. The order of lead and arsenic concentrations in muscles of wild birds were as follows: mallard > pheasant > Eurasian coot; in the case of arsenic the differences were significant (P < 0.05). Muscle of Eurasian coot accumulated the highest concentration of cadmium and mercury followed by pheasant and the lowest in mallard, but differences were not significant (P > 0.05). Moderately negative correlations were noted in pheasant between cadmium and mercury (r = -0.39), and between mercury and arsenic (r = -0.45). Moderately negative correlation between cadmium and arsenic (r = -0.31) was found for Eurasian coot.

The aim of this study was to investigate the effect of dietary supplementation of seaweed on the reproductive performance of rabbits. Two trials were performed during this study. In the first trial, semen quality was evaluated in 15 buck rabbits with mean body weight of 4.8090.41 kg and six month of age. In the second trial, prolificacy was determined in 30 artificially inseminated does with a mean body weight of 4.8490.50 kg and five to six months of age. Rabbits in each trial were randomly allocated to one of three dietary seaweed levels; commercial pelleted diet (C), pelleted diet supplemented with 1% seaweed (T 1 ), and pelleted diet supplemented with 2% seaweed (T 2 ). Dietary supplementation of seaweed significantly increased plasma testosterone concentration and improved various sperm motility parameters. Analysis of acrosomal membrane integrity using electron microscopy revealed no significant influences of dietary seaweed supplementation on quality grade (IÁIV) of all tested samples. These results reflected in positive prolificacy response of does artificially inseminated with semen samples pooled from bucks fed on T 2, and offered diet supplemented with 2% seaweed one week prior to their insemination and throughout the gestation period. Feeding diets supplemented with 2% seaweed to doe rabbits improved their kindling rate, litter size, and their offspring ratio. Seaweed supplementation to the diets of rabbits raised under summer conditions had improved their reproductive performance by improving the semen fertility characteristics of bucks and the prolificacy characteristics of does. Hematological and biochemical parameters investigated in this study did not reveal any pathological signs in both rabbit's genders due to dietary seaweed supplementation.