ISSN:
1573-0875
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Geologie und Paläontologie
Notizen:
Abstract Rats and mice were exposed for periods of up to six months and two successive generations of mice were raised in a ground-level chamber system filled with 80% helium −20% oxygen, at 24°C. A duplicate chamber for controls contained a comparable nitrogen-oxygen mixture, and in both the other environmental parameters were well-controlled and nearly identical. Animals adapted to helium showed no greater increase in oxygen consumption (P〉0.05) when placed in helium-oxygen than did those raised in air. Growth rates were identical, but the helium mice consumed more food and water. Selected biochemical analyses were made on the parent and two successive generations of mice. These included blood indices; electrophoretically separated tissue protein patterns from liver, skeletal muscle, and cardiac muscle; quantitative determinations of LDH, MDH, and G6PDH from the same tissues; serum insulin; and semi-quantitative histochemical estimates of liver glycogen. No cases of statistically significant difference or consistent trends were seen between the experimental environmental groups. Additional analyses of liver nucleotides and redox-coenzymes also failed to show a significant difference. The relative weights of liver, heart, kidney, and diaphragm (wet and dry) were the same in both groups. Histopathological examination of kidney and adrenal tissue produced unremarkable findings and none that were attributable to the nature of the gaseous environment. It must be concluded that prolonged exposure to helium-oxygen, relative to air, does not produce detectable changes in several key subcellular factors which might be altered by serious metabolic disturbances, and therefore the helium exposure is well tolerated.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00928956
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