Lifetime exposure to low doses of lead in rats: effect on selected parameters of carbohydrate metabolism.

The aim of the study was to assess the effects of exposure to low doses of lead dissolved in drinking water (average daily dose of 2.2 mg kg(-1) day(-1)) on selected carbohydrate metabolism parameters in 20 wistar rats. Animals were divided into two groups - control (C) (group drinking clear water) and experimental group (Pb; group exposed to low doses of lead acetate in a concentration of 100 µmol l(-1) of drinking water). In this study, we studied the biochemical parameters (glucose, haemoglobin (Hb), glycated haemoglobin (HbA1c), lactate dehydrogenase (LDH) and amylase (AMS)) in rat blood. Glucose and Hb concentration and AMS activity decreased, LDH activity increased but HbA1c concentration levels did not change in rats exposed to lead. Our results well documented that lifetime exposure to lead affected carbohydrate metabolism of rats. Some parameters like concentration of Hb as well as activities of AMS and LDH are useful markers of intoxication of rats with lead. For the evaluation of results (e.g. AMS), not only the data at the end of the experiment should be taken into account but also the entire duration of trials (i.e. more time steps) that makes results more objective should be considered.

Effects of chronic low-dose cadmium exposure on selected biochemical and antioxidant parameters in rats.

The effects of long-term (1 yr) exposure to low doses of cadmium (Cd) dissolved in drinking water on selected biochemical and antioxidant parameters were studied in Wistar rats. Rats were divided into four groups: male control group (C-m), female control group (C-f), male Cd-exposed group (Cd-m), and female Cd-exposed group (Cd-f). Cd groups were exposed to Cd dissolved in drinking water (cadmium dichloride 4.8 mg CdCl2/L, i.e., 2.5 mg Cd/L, 500-fold of maximal allowable concentration for potable water). The experiment was terminated on d 370. In all groups, biochemical parameters (total protein [TP], albumin, alanine aminotransferase, aspartate aminotransferase, glucose, cholesterol, triacylglycerols, urea, and creatinine) and antioxidant parameters (glutathione peroxidase, superoxide dismutase, and total antioxidant capacity) were measured in the blood. Total protein and albumin concentrations were decreased significantly in the Cd-m group. Other biochemical parameters did not change in Cd groups compared to control groups. Superoxide dismutase fell significantly in both male and female Cd-exposed groups. Activity of glutathione peroxidase was markedly lower in Cd-exposed groups. Total antioxidant capacity increased significantly in Cd-f group. These results suggest that chronic low-dose oral Cd exposure induces oxidative stress.

Age dependency on some physiological and biochemical parameters of male Wistar rats in controlled environment.

The aim of the study was to assess the age dependence on some physiological and serum chemistry parameters of male Wistar rats for the estimation of reference values in controlled environment. We are presenting values obtained from a large number of animals such as survival, average life span, body mass, food and water intake, serum chemistry parameters as total protein, albumin, transferrin and ferritin in serum. One part of this work compares the relationship between rat and human age. The maximal life span of our rats was determined to be about 4.4 years. The average life span was 3.75 years. The body weight quickly rose to the 85th week of life and then remained in the range of about 640-660 g up to the 163rd week when it began to decline. Food intake rose from the beginning to the maximum of about 39 g in the 33rd week and then decreased to about 20 g in the 163rd week. The water intake had a similar dynamics (about 43 mL in the 33rd week and 33 mL in the 163rd week). Levels of total protein in serum increased with age, in contrast, albumin levels decreased. Transferrin and ferritin decreased to approximately the 160th week of life and then increased.

Multigenerational lifetime low-dose exposure to heavy metals on selected reproductive parameters in rats.

The aim of the present investigation was to evaluate the effects of multigenerational (P, F1 and F2) exposure to low doses of lead, mercury and cadmium dissolved in tap water on the reproductive potency of Wistar rats and the physical health of their progeny. The animals were divided into 4 groups - control (C) and 3 groups intoxicated by metals (Pb, 100 µM; Hg, 1 µM; Cd, 20 µM, respectively). Females gave births from the 13th to the 78th week of experiment. Parameters of reprotoxicity such as number of litters, total number of neonates (assigned in the birth day), and number of weanlings (28th day after birth) were measured in 13-week intervals. Our data show an increase of most reproductive parameters in parental generation of rats exposed to lead and mercury and a decrease of reproductive parameters of exposed animals in subsequent F1 and F2 generations. Exposure to cadmium had no significant effect on the reproductive parameters in comparison with the control group.

Effect of lifetime low dose exposure to heavy metals on selected serum proteins of Wistar rats during three subsequent generations.

The aim of the study was to assess the effects of exposure to low doses of lead, cadmium and mercury dissolved in drinking water (at a concentration 200-fold of maximum allowable concentration) on selected serum proteins of 120 Wistar rats during three subsequent generations. Animals were divided into four groups in all observed generation-control (C) and three experimental groups exposed to low doses of heavy metals (lead acetate in concentration 100 µM; mercuric chloride in 1 µM; cadmium chloride in 20 µM of drinking water). We studied the biochemical parameters as well as total protein, albumin, transferrin and ferritin in the serum. Exposure to lead and mercury shortened life span, decreased body weight of the animals in each generation whereas cadmium had no such effect. Total protein increased after exposure to lead and mercury (P<0.001), albumin increased after exposure to lead and mercury in 1st filial and 2nd filial generation (P<0.05) and insignificantly decreased after exposure to cadmium in parental and 1st filial generation. Transferrin and ferritin increased in all exposed groups and generations (P<0.05). Transferrin and ferritin are good markers for intoxication of rats with heavy metals. For the results evaluation, not only data at the end of experiment should be taken into account, but entire duration of trials (i.e., more time steps), which makes results more objective.

Vitamin E-coated dialyzer and antioxidant defense parameters: three-month study.

Atherosclerotic cardiovascular disease is the most frequent cause of death in patients with end-stage renal disease who have undergone dialysis treatment. Oxidative stress, increased lipid peroxidation, and impaired function of antioxidant systems may contribute to the accelerated development of atherosclerosis in chronic renal failure patients during renal replacement therapy. The aim of this study was to investigate the influence of a vitamin E-coated dialyzer on antioxidant defense parameters in hemodialysis (HD) patients. In 14 HD patients, hemodialysis was performed using a vitamin E-coated dialyzer (Terumo CL-E15NL; Terumo Corporation, Tokyo, Japan) during a 3-month study. In these patients, erythrocyte (ER) antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR) and catalase (CAT), plasma total antioxidant capacity (TAC), RBC glutathione (GSH), plasma malondialdehyde (MDA), plasma, and RBC vitamin E were investigated. Each parameter was measured at the beginning of the study, after the 1st, 2nd, and 3rd month of the study, and 10 weeks after the interruption of the use of vitamin E-coated dialyzer. All HD patients were treated by erythropoietin (EPO) and received vitamin C 50 mg/d, pyridoxine 20 mg/d, and folic acid 5 mg/wk during the entire study. The 3-month treatment with the vitamin E-coated dialyzer led to a significant decrease of plasma MDA level (from 2.85 +/- 0.44 to 2.25 +/- 0.37 micromol/L) and to an increase of plasma TAC, RBC, GSH, and the vitamin E levels both in plasma (from 25.9 +/- 2.8 to 33.6 +/- 3.8 micromol/L) and in the RBCs (from 6.7 +/- 0.8 to 7.4 +/- 0.7 micromol/L) by 30% and 10.5%, respectively. Ten-week interruption of the use of the vitamin E-coated dialyzer led to near initial values of MDA (2.90 +/- 0.28 micromol/L), plasma (28.6 +/- 3.5 micromol/L), and RBC (6.9 +/- 0.7 micromol/L) vitamin E and of other investigated parameters. Statistical analysis of results was performed by conventional methods and analysis of variance. The findings of the current study confirm the beneficial effect of the vitamin E-coated dialyzer against oxidative stress in HD patients.