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T Moore

Publications and source records attributed to T Moore.

At least 235 records · Page 13Linked to original sources
PubMed1967

Nutrition and lysosomal activity. The influence of vitamin E deficiency and its duration on the stability of lysosomes in the kidneys of rats.

1. Experiments on rats were made to find whether the increased liability of the kidney-cortex tubules to autolysis post mortem, which is a well-established abnormality in vitamin E deficiency, can be correlated with changes in lysosomal activity. Parallel observations were made on the development of certain other abnormalities characteristic of avitaminosis E. 2. In rats killed after long periods (8-10 months) of subsistence on a standard vitamin E-deficient diet, containing lard, both the rate of kidney autolysis post mortem and the enzyme activity of lysosome preparations from the fresh tissues were much greater than in controls. A greater percentage difference was usually found in the ;free' enzyme fraction than in ;bound' or ;total' activity. 3. In rats killed after graded periods (3-8 months) of deficiency, two abnormalities (decreased resistance of the erythrocytes to haemolysis, and brown discoloration of the uterus) were already evident at a stage (3-4 months) when the liability to rapid kidney autolysis had not begun. At this point the enzymic activity of kidney extracts differed little between deficient animals and controls given alpha-tocopherol. As the duration of deficiency advanced, parallel increases occurred in the rate of kidney autolysis and in lysosomal instability. 4. When cod-liver oil, rich in polyunsaturated fatty acids but freed from vitamin A, was substituted for lard in the diet, the time (1(1/2) months) required for the inducement of both rapid kidney autolysis and decreased lysosomal stability was greatly shortened. The time for the inducement of brown discoloration of the uterus was not shortened and the kidney abnormalities appeared while the uterus was still normal. 5. Confirmation was thus obtained for the view that the various tissues of the rat respond differently to the relationship between the adequacy of the vitamin E status and the intake of polyunsaturated fatty acids. The kidney-cortex tubules, as evidenced by autolysis post mortem and the corresponding decrease in lysosomal stability, may be classed among those tissues that are most sensitive to the effect of high intakes of polyunsaturated acids.

Animals↗
PubMed1966

Nutrition and lysosomal activity. The influence of the vitamin A status on the proteolytic activity of extracts from the livers and kidneys of rats.

1. Young rats were kept for several weeks on a diet deficient in vitamin A. Some were undosed, others were given marginal (25i.u. weekly), adequate (1000i.u. weekly) or excessive (50000i.u. daily) doses of vitamin A acetate. The undosed rats developed signs of vitamin A deficiency, and the overdosed animals had skeletal fractures indicative of hypervitaminosis A. 2. The rats were decapitated. Their livers, and sometimes their kidneys, were homogenized and processed by centrifugal methods to sediment most of the lysosome fractions. Proteolytic activity was measured, after treatment with a detergent, in the whole homogenate (;total' activity), in the pellet obtained after 20min. at 15000g (;bound' activity) and, without treatment with detergent, in the supernatant (;free' activity). 3. In rats suffering from hypervitaminosis A the free activity and to a smaller extent the total activity were increased. Free activity was also raised in most rats suffering from avitaminosis A, but less than in those suffering from hypervitaminosis. 4. The vitamin A status appeared to have little effect on the proteolytic activity of the kidneys. Results for total and free activities, but not for bound activities, were higher than for corresponding liver preparations. 5. Control experiments were done on starved rats and on rats which were pair-fed with hypervitaminotic animals. Short periods of starvation caused an increase in free activity in young rats, but not in adults. The increases caused by starvation were much less than those caused by hypervitaminosis A. 6. For studies of the distribution of vitamin A more complete separation of the subcellular fractions was carried out on the combined livers from several hypervitaminotic rats. The concentration of vitamin A in the lysosome fraction was less than in the liver as a whole. 7. Our finding that the free proteolytic activity of the liver is increased by toxic oral dosing with vitamin A can be considered an extension of the previous observation that proteolytic enzymes are liberated when lysosomes are treated in vitro with vitamin A.

Animals↗