Effects of dietary supplementation of nickel and nickel-zinc on femoral bone structure in rabbits

<p>Abstract</p> <p>Background</p> <p>Nickel (Ni) and zinc (Zn) are trace elements present at low concentrations in agroecosystems. Nickel, however, may have toxic effects on living organisms and is often considered as a contaminant. This study reports the effect of peroral administrated Ni or a combination of Ni and Zn on femoral bone structure in rabbits.</p> <p>Methods</p> <p>One month-old female rabbits were divided into three groups of five animals each. Group 1 rabbits were fed a granular feed mixture with addition of 35 g NiCl₂per 100 kg of mixture for 90 days. In group 2, animals were fed a mixture containing 35 g NiCl₂and 30 g ZnCl₂per 100 kg of mixture. Group 3 without administration of additional Ni or Zn served as control. After the 90-day experimental period, femoral length, femoral weight and histological structure of the femur were analyzed and compared.</p> <p>Results</p> <p>The results did not indicate a statistically significant difference in either femoral length or weight between the two experimental groups and the control group. Also, differences in qualitative histological characteristics of the femora among rabbits from the three groups were absent, except for a fewer number of secondary osteons found in the animals of groups 1 and 2. However, values for vascular canal parameters of primary osteons were significantly lower in group 1 than in the control one. Peroral administration of a combination of Ni and Zn (group 2) led to a significant decreased size of the secondary osteons.</p> <p>Conclusions</p> <p>The study indicates that dietary supplementation of Ni (35 g NiCl₂per 100 kg of feed mixture) and Ni-Zn combination (35 g NiCl₂and 30 g ZnCl₂per 100 kg of the mixture) affects the microstructure of compact bone tissue in young rabbits.</p

Zinc supplementation ameliorates electromagnetic field-induced lipid peroxidation in the rat brain

Extremely low-frequency (0-300 Hz) electromagnetic fields (EMFs) generated by power lines, wiring and home appliances are ubiquitous in Our environment. All populations are now exposed to EMF, and exposure to EMF may pose health risks. Some of the adverse health effects of EMF exposure are lipid peroxidation and cell damage in various tissues. This study has investigated the effects of EMF exposure and zinc administration on lipid peroxidation in the rat brain. Twenty-four male Sprague-Dawley rats were randomly allocated to three groups; they were maintained untreated for 6 months (control, n=8), exposed to low-frequency (50 Hz) EMF for 5 minutes every other day for 6 months (n=8), or exposed to EMF and received Zinc sulfate daily (3 mg/kg/day) intraperitoneally (n=8). We measured plasma levels of zinc and thiobarbituric acid reactive substances (TBARS), and levels of reduced glutathione (GSH) in erythrocytes. TBARS and GSH levels were also determined in the brain tissues. TBARS levels in the plasma and brain tissues were higher in EMF-exposed rats with or without zinc supplementation, than those in controls (p<0.001). In addition, TBARS levels were significantly lower in the zinc-supplemented rats than those in the EMF-exposed rats (p<0.001). GSH levels were significantly decreased in the brain and erythrocytes of the EMF-exposed rats (p<0.01), and were highest in the zinc-supplemented rats (p<0.001). Plasma zinc was significantly lower in the EMF-exposed rats than those in controls (p<0.001), while it was hi-hest in the zinc-supplemented rats (p<0.001). The present study suggests that long-term exposure to low-frequency EMF increases lipid peroxidation in the brain, which may be ameliorated by Zinc Supplementation

Effects of zinc deficiency and pinealectomy on cellular immunity in rats infected with Toxoplasma gondii

The effects of zinc and/or melatonin deficiencies on cellular immunity were investigated in rats infected with Toxoplasma gondii. A total of 50 adult male Sprague-Dawley rats were divided into 5 groups of 10 rats each. In group 1, the rats were infected with T gondii and fed a zinc-deficient diet; in group 11, the rats were infected and their pineal gland was surgically removed. Group III included rats that were infected, pinealectomized, and fed a zinc-deficient diet. Group IV consisted of T gondii-infested rats that received no treatment of any kind, and group V were normal controls. After 3 wk of treatment, all rats were sacrificed and the percentages of CD3, CD4, and CD8 lymphocytes, zinc, and melatonin levels in plasma and the percentage of lymphocyte in blood smears were analyzed. The CD3 ratios of groups I-III were significantly lower than those of groups IV and V (p<0.01). The CD4 lymphocytes were significantly higher in group TV than that in all other groups (p<0.05). In group IV, the CD8 lymphocytes were higher than in groups I-III (p<0.01) and those in group V were higher than for groups I and III (p<0.01). Lymphocyte incidence in group IV was higher than in the other four groups (p<0.01). The plasma zinc and plasma melatonin levels in groups I-III were significantly lower than those in the controls (p<0.01, both cases). These results suggest that zinc and/or melatonin deficiency have a negative influence on cellular immunity in rats with toxoplasmosis

Investigation of serum leptin levels in professional male football players and healthy sedentary males

OBJECTIVE: In the present study we aimed at investigating leptin levels in professional male athletes who have been exercising regularly for a long time and leptin levels in healthy sedentary males

The relation between serum leptin levels and max VO2 in male patients with type I diabetes and healthy sedentary males

This study aimed at investigating leptin levels in male diabetes type I patients who were on insulin treatment and also healthy sedentary males. The study included 10 male type I diabetes patients and 17 healthy sedentary males. Leptin levels of type I diabetes patients and healthy sedentary males with body mass index (BMI) over 25 kg/m(2) were evaluated separately. The relation between serum leptin, max VO2, blood lactic acid levels before and after exercise, and effort durations of participants were investigated. At the end of the tests, no difference was found between leptin levels, max VO2 values, lactic acid values before exercise, and test durations of male type I diabetes patients and healthy sedentary males (p > .05), whereas lactic acid levels after exercise were found to be lower in healthy sedentary males (p < .05). Leptin levels in the group with BMI above 25 kg/m(2) were higher than those in the group with BMI below 25 kg/m(2) (P < .001). It was also seen that max VO2 values and test durations were higher in the group with BMI below 25 kg/m(2) (p < .05). In conclusion, leptin levels of male type I diabetes patients are close to those of healthy sedentary males. The increase in leptin levels in both groups is in proportion to the BMI of individuals

The effect of pinealectomy and zinc deficiency on nitric oxide levels in rats with induced Toxoplasma gondii infection

Principles: This study aims at investigating how zinc deficiency and pinealectomy affect nitric oxide levels in rats infected by Toxoplasma gondii

Opposite effects of zinc and melatonin on thyroid hormones in rats

The present study was conducted to investigate how thyroid function in rats is affected by administration of 3 mg per kg per day of zinc and/or melatonin

Pinealectomy and zinc deficiency have opposite effects on thyroid hormones in rats

The present study was conducted to investigate how pinealectomy and zinc deficiency separately or in combination affected thyroid hormones in rats. The study was carried out on 40 Sprague-Dawley male rats. The rats were equally allocated to four groups: Group 1 (control group), Group 2 (zinc-deficient group), Group 3 (pinealectomized group) and Group 4 (pinealectomized and zinc-deficient group). At the end of a 4-week study period, the rats were decapitated and blood samples were taken. The samples were examined in terms of plasma zinc, melatonin, free and total T-3, T-4, and TSH. It was found that free T-3 and T-4 levels in the pinealectomized group (Group 3) were higher than all others (p < 0.01) while free T-3, T-4, and TSH levels in the zinc-deficient group (Group 2) were lower than all others (p < 0.01). Free T3 and T4 levels in the pinealectomized zinc-deficient group (Group 4) were lower than those in Groups I and 3 and higher than those in Group 2 (p < 0.01). The findings obtained at the end of the study period show that pinealectomy has a stimulating and zinc deficiency has a suppressing effect on thyroid hormones and that the suppressing effect caused by zinc deficiency is partially balanced by pinealectomy