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Biomedical subjects

S Krishnamurthy

Publications and source records attributed to S Krishnamurthy.

69 records · Page 4Linked to original sources
PubMed1979

Effect of lipid antioxidants on rat erythrocyte hemolysis.

Lipid antioxidants, DPPD, DAH, BHT, SQ, retinol and alpha-tocopherol were studied for their effects on normal rat erythrocytes. Retinol, BHT and SQ were found to induce hemolysis while DPPD, DAH and alpha-tocopherol were non-hemolytic. Further more the three antioxidants BHT, SQ and retinol showed a synergistic effect on the lysis. Retinol, BHT or SQ alone, and BHT or SQ along with retinol when administered to rats produced a marked modification of the erythrocyte membrane integrity, simultaneously lowering the levels of membrane bound enzymes--acetyl choline esterase and ATPase. It is concluded that the lipid antioxidants may therefore be classified on the basis of their lytic action in vitro.

Animals↗
PubMed1978

Effect of vitamins, antioxidants and sulfhydryl compounds on in vitro rat brain lipid peroxidation.

The effect of retinol, retinylacetate, alpha-tocopherol, alpha-tocopherylacetate, synthetic antioxidants (DPPD, BHT, DAH, and Ethoxyquine) sulfhydryl compounds (reduced glutathione and cysteine) on rat brain lipid peroxidation has been studied using the TBA method. Retinol and retinyl acetate inhibit brain lipid peroxidation, alpha-tocopherol is less effective than vitamin A, while alpha-tocopherol acetate has no antioxidant property. Ascorbic acid stimulates the peroxidation, at pH 5.0. The synthetic antioxidants are all potent inhibitors of brain lipid peroxidation, DPPD being the most effective, while the sulfhydryl compounds at a concentration of 1 x 10(-3)M has a slight potentiating effect.

Animals↗
PubMed1978

Effect of hypervitaminosis A on hemolysis and lipid peroxidation in the rat.

Erythrocytes from rats fed large doses of Vitamin A alone, or large doses of vitamin A and vitamin E or diphenyl-p-phenylene diamine (DPPD) were studied for H2O2-induced hemolysis. The vitamin A-dosed rats were more susceptible than normal rats to H2O2-induced hemolysis. Hemolysis was not accompanied by lipid peroxidation. Nevertheless, the antioxidants vitamin E and DPPD inhibited hemolysis in erythrocytes from vitamin A-dosed rats. These antioxidants had the same inhibitory effect when they were included in the diet or added to erythrocyte suspensions in vitro. Erythrocytes from vitamin A-dosed rats with or without added vitamin E or DPPD were less susceptible than the erythrocytes from normal rats to osmotic challenge, showing that vitamin A was present in levels sufficient to alter the structure of the erythrocyte membrane. These studies show that oxidative hemolysis occurs when the erythrocyte membrane is modified. Furthermore, this oxidative hemolysis is unrelated to lipid peroxidation.

Animals↗
PubMed1977

Antioxidant function of vitamin A.

Feeding of 100 000 I.U. of Vitamin A on alternate days, five times to rats, resulted in a marked lowering in in vitro lipid peroxidation of the tissue hemogenates. alpha-Tocopherol or DPPD supplementation along with A still further reduced the in vitro lipid peroxidation of the tissues. Vitamin A in large doses increased the antioxygenic potential of the tissues, and it is suggested that retinol also might be considered as a potential antioxidant similar to tocopherol in animal nutrition.

Alopecia↗
PubMedDate not supplied

The Kveim test in leprosy.

The response to lepromin and Kveim antigens was compared and studied in 15 leprosy patients who were tuberculin negative. Of the 11 lepromin positive tuberculoid patients, 4 were Kveim positive, 1 was equivocal, and the rest were negative. Of the four lepromin negative lepromatous patients, one gave a positive Kveim test while the other three were negative. It has been shown that false-positive Kveim reactions are found in a higher percentage of South Indian leprosy patients than in those of other backgrounds, such as Japanese and Malaysian Chinese patients. It is also suggested that no definite relationship exists between the reaction of leprosy patients to lepromin and Kveim antigens. We further suggest that the anergy exhibited by lepromatous patients to the antigen of M. leprae is specific, as evidenced by the positive Kveim response in one lepromatous patient.

China↗
PubMedDate not supplied

Factors affecting in vitro lipid peroxidation of rat brain homogenate.

Peroxidation of the unsaturated lipid of tissue homogenates is an established method to assess the antioxidant or vitamin E status of animals. In the present study the spontaneous lipid peroxidation in air of rat brain homogenates is reported. The effects of various factors like pH, time, concentration of tissues, temperature, ferrocompounds and catalysis by added tissues like liver are described. Rat brain homogenates appear to be a suitable preparation for in vitro studies of lipid peroxidation.

Animals↗