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Biomedical subjects

M Blanusa

Publications and source records attributed to M Blanusa.

At least 55 records · Page 3Linked to original sources

The effect of 2,3-dimercaptopropane sodium sulfonate on mercury retention in rats in relation to age.

The effectiveness of DMPS (sodium 2,3-dimercaptopropane-1-sulfonate) in reducing inorganic mercury retention was studied in 2-, 6-, and 28-week-old albino rats. 203Hg was administered IP. The chelating agent DMPS was administered by IP injection at a dose of 250 mumol/kg body weight three times, 1 day after 203Hg administration and at 24 h intervals thereafter. The whole body retention determined 1, 2, 3, and 6 days after 203Hg administration showed that DMPS decreased the body retention of mercury in all age groups, being about twice as effective in adult compared to suckling rats. The reduced effectiveness was due to the reduced efficacy of DMPS in reducing kidney retention in young animals. In other organs the effectiveness of DMPS was not age dependent. These and previous results obtained with different chelating agents and other metals indicate that age might be an important factor in chelation therapy in general.

Age Factors↗

Lower efficiency of DTPA in reducing cadmium retention in suckling rats.

The influence of age on the effectiveness of chelation therapy in enhancing cadmium elimination was studied in 1-, 2-, 8-, and 26-week-old rats. 115mCd was administered intraperitoneally, followed immediately and after 24 hr by an intraperitoneal injection of trisodium calcium diethylenetriaminepentaacetate (DTPA) (600 mumole/kg body wt). The whole body retention determined on the second, fourth, and sixth days of the experiment showed that DTPA greatly decreased cadmium retention in all age groups being about four times more effective in older than younger animals. Determination of 115mCd retention in the gut and organs also revealed that effectiveness of DTPA was lowest for the youngest age group and increased with increasing age. This effect of DTPA was more pronounced in the liver than in the kidney and brain in all age groups. These results indicate that age greatly influences chelation of cadmium and that age might be an important factor in chelation therapy in general.

Aging↗

Age and intestinal retention of mercury and cadmium in rats.

The site of cadmium and mercury retention in the intestine was determined in 6-day-old sucklings and 6-week-old weaned rats 6 days after oral administration of 115mCd and 203Hg. The ileum was found to be the main site of intestinal retention of both cations in sucklings but not in weaned rats. Other age- and element-specific differences in the site of metal retention in the intestine were also found. These differences indicate that even in neonates, metal absorption might be a more specific process than previously assumed.

Aging↗

Chronic and reproduction studies in rats exposed to gasifier ash leachates.

Ash from the coal gasification process contains a broad spectrum of elements which through leaching (gasifier ash leachates) may enter into the environment. The health effect of such leachates i.e. complex mixtures of inorganic elements is insufficiently known. We investigated the effect of gasifier ash leachates in a chronic-(9-month) and in a three-generation reproduction study. The leachates were prepared weekly by water extraction of ash from a Lurgi coal gasification plant in Yugoslavia, and given to experimental animals instead of drinking water. In the chronic experiment exposed animals showed no changes in mortality rate, haematological findings, concentration of Fe, Zn, Mn in kidneys, liver, testicles and femur, as well as in femur composition and morphometry, gross pathology and organ histology. In the reproduction study the number of pregnancies, weight and number of newborns, and concentration of Fe, Zn, Mn in carcasses of sucklings were the same in control and experimental animals.

Animals↗

Chronic studies in rats exposed to liquid effluent from coal gasification process.

The health effects of the E-effluent (water for quenching ash) from a coal gasification plant were assayed in a chronic experiment (16 month exposure) and a three generation reproduction study. Animals exposed to 100% E-effluent had an increased daily intake of various inorganic elements (Fe, Cu, K, I, Se, Cd, Hg, Pb, As, F and Cr). In spite of that, the exposed and control animals had the same mortality rate, haematological findings, urinary protein excretion, trace element concentrations in kidneys, liver and femur, bone composition and morphometry, and histological findings. The pre- and post-natal development and growth was unchanged during three generations. It is concluded that the higher intake of various inorganics caused no change in the parameters measured.

Animals↗

Simultaneous reduction of radioactive strontium, caesium and iodine retention by single treatment in rats.

The effect of a mixture of calcium alginate, iron (III) ferrocyanide and potassium iodide added to rat diet on 85Sr, 137Cs and 131I metabolism and health was investigated in female rats after four weeks of treatment. The retention of these radioisotopes was determined in the whole body and critical organs six days after 85 Sr and 137CS and one day after 131I oral administration. The health effect of the mixture was evaluated by measuring body weights, haematological parameters, concentrations of iron, zinc and manganese in the kidneys, liver and femur, bone parameters (femur composition and morphometry) and by a histopathological examination. The mixture reduced 85Sr retention in the femur 11 times, 137Cs retention in the thigh muscle 102 times and 131I retention in the thyroid 134 times. Treated animals were in good health and the only differences found between the control and experimental rats were slightly lower haemoglobin values in the blood and a slightly lower iron concentration in the liver. It is concluded that the mixture was very efficient for decreasing body retention of three important fission products and that it can be used over long periods without causing adverse health effects.

Alginates↗

More data on mercury absorption in relation to dietary treatment in rats.

The kinetics of mercury (Hg) absorption in relation to diet by determining whole body (WB), carcass (C) and gut (G) retention in control and milk-fed rats 6, 9, 12 and 15 days after oral administration of 203Hg have been studied. All retention values were higher in the milk-fed than in control rats during the experimental period. The higher WB retention in the milk-fed animals was primarily due to increased G retention especially at shorter time intervals. Animals on the milk diet had in the C, higher retention values, and in the G, higher retention and longer residence time. There was no evidence that Hg from the gut compartment entered into other parts of the body within the observation period. More evidence is needed about the effect of other dietary treatments on Hg metabolism.

Animals↗

Toxicologic studies of emissions from coal gasification process. I. Subchronic feeding studies.

The increasing use of new sources of energy may result in additional contamination of the human environment with inorganic and organic pollutants which are not yet adequately investigated with regard to their potential impact on human health. However, some evidence exists that several trace inorganic and organic contaminants found in coal processing residues may constitute potential health problems. Therefore, the comparative biological hazards of solid wastes and effluents from a Lurgi coal gasification plant were initially evaluated using acute and chronic feeding experiments in male and female rats. In the subchronic experiment, six-week old animals were fed diets wih various levels of ash (slag) additive (0.5%, 1%, and 5%) for period of 16 weeks. Following exposure, blood samples were taken and 22-hour urine samples were collected. Livers and kidneys, and testicles in males, were taken for trace element analysis or histologic examination. The urinary values, erythrocyte and leucocyte count, hemoglobin, packed cell volume, and concentration of trace elements in exposed animals were determined. The addition of ash (slag) to the diet in concentrations much higher than expected in conditions of environmental contamination had no measurable health effects. Although these initial results obtained in relatively short-term experiments cannot be directly extrapolated to human health effects, particularly not for carcinogenic assessment, there is an indication that exposure to solid wastes from the coal gasification plant may not be toxic.

Animals↗

Influence of some factors on cadmium pharmacokinetics and toxicity.

Cadmium metabolism in the young and in conditions of dietary contamination with ash from coal gasification were investigated. The experiments were performed in adult rats which received ash in the diet (5%) and/or cadmium in drinking water (100 ppm) over a period of five weeks and in sucklings whose mothers were given the same treatment throughout pregnancy and lactation. In pharmacokinetic studies, (115m)Cd was administered orally or intraperitoneally to determine the intestinal absorption, retention, and distribution. Cadmium toxicity (LD(50)) was determined in different age groups of animals treated with ash for five weeks before a single oral or intraperitoneal administration of cadmium chloride. After intraperitoneal administration, (115m)Cd body retention decreased with age and was independent of the dietary treatment. Sucklings had a higher retention in the blood, carcass, and gut than adults. After oral administration, sucklings had a much higher body retention than adults regardless of the dietary treatment of their mothers. Cadmium toxicity was also independent of the dietary treatment. Most striking was a very high oral toxicity of cadmium in sucklings. It is concluded that the young might be at a special risk at the same level of environmental cadmium exposure because of the high oral cadmium toxicity at this age which is most probably due to a high cadmium retention in the gut. It is also concluded that the mixture of elements contained in ash is not likely to influence cadmium metabolism and toxicity in conditions of dietary exposure.

Age Factors↗

Kinetic parameters of calcium metabolism and femur morphometry in rats. I. Influence of sex and age.

The aim of this study was to establish the influence of age and sex on the kinetic and morphometric parameters of calcium metabolism. Normal values of kinetic parameters were determined in normal adult rats of different ages (4--20 months) and both sexes. Urinary hydrophyline excretion was also assessed and morphometric measurements of the femur were performed. Kinetic parameters expressed as rate constants showed a lowering of calcium turnover (kr) in the rapidly exchangeable calcium compartment until the age of 12 months and urinary and fecal rate constants (ku and kf) showed a small increase. Males exhibited a lower calcium turnover (kT) as well as lower urinary and fecal rate constants. Hydroxyproline excretion diminished with age in both sexes. Lower values were recorded in males. Morphometric parameters of femurs showed no bone loss within the examined age. The results show that differences between the sexes exist in the sense of a faster calcium turnover, higher calcium excretion rate constants, higher collagen degradation and higher bone density in adult female rats.

Aging↗