C. R. Krishna Murti

Ascorbic acid—a naturally occurring mediator of lipid peroxide formation in rat brain

Male albino rats (body wt. 3G50g) drawn from the CDRI Stock Colony were fasted overnight. They were decapitated and their whole brains were excised and washed with cold 150 mM-potassium chloride. Homogenates (10% w/v) were prepared in chilled 150 mwpotassium chloride and centrifuged at 80Oy for IOmin. The supernatant fluid was centrifuged at 18,000g for 15 min and the resultant supernatant fluid was centrifuged at 106,000 for 1 h to recover the organelle-free cytosol fraction. The pellet sedimenting at 18,OOOy was suspended in 150 mM-potassium chloride and washed by centrifugation and finally suspended in 150 mM-potassium chloride to a final protein concentration of 6 mg/ml. This was referred to as mitochondrial fraction. Assay of lipid peroxides. Samples of 0.5 ml of the source of pro-oxidant were mixed with 0.25 ml of the mitochondrial fraction. The flasks containing the mixture were shaken in a metabolic shaker (120 strokes/min) for 3 h a t 37°C. One millilitre of 10% w/v trichloroacetic acid was added and after thorough mixing, the reaction mixture was centrifuged at 800 y for 10 min. Samples (1 ml) of the clear supernatant fluids were mixed with 1 ml 0.67% w/v 2-thiobarbituric acid and held in a boiling water bath for 10 min, cooled and diluted with 1 ml distilled water. The absorbance of the solution was read at 535nm and results expressed as malonyldialdehyde using 1.56 x lo5 as extinction coefficient (UTLEY et a/., 1967). Chemical esfimutions. Protein was estimated according to LOWRY et al. (1951), sulphydryl groups according to ELLMAN (1959), ascorbic acid according to ROE & KUENTHEK (1943) (bromine as oxidizing agent), ACh according to HESTRIN (1949) and amino acids according to MOORE & STEIN (1948). Preparation and assay of ascorbic acid oxidase (EC 1.10.3.3). The enzyme was prepared from the bottle gourd (Lagenaria siceraria) and assayed by the procedure Of LOVETT-JAMISON & NELSON (1940).

Effect of indole-3-acetic acid on the synthesis of cyclic 3'-5' adenosine phosphate by bengal gram seeds

Indole-3-acetic acid ( IAA ) was found to exert a two fold stimulation of the synthesis of cyclic 3′–5′ adenosine phosphate ( cyclic-AMP ) in 72 hr seedlings of Bengal gram as judged from the increased incorporation of 8-C 14 adenine into cyclic-AMP in presence of the hormone.

Glycolysis in Litomosoides carinii, the filarial parasite of the cotton rat☆

Extracts of Litomosoides carinii, the cotton rat filarial parasite, possess significant activities of glycogen phosphorylase, phosphoglucomutase, phosphoglucoseisomerase, a nonspecific hexokinase acting on glucose, mannose, galactose and fructose, phosphofructokinase, aldolase, glyceraldehyde phosphate dehydrogenase, enolase, pyruvatekinase, lactate dehydrogenase, phosphoenolpyruvate carboxykinase, and malate dehydrogenase along with phosphatases acting on glucose-6-phosphate and fructose diphosphate. The results indicate the functioning of the glycolytic pathway in this worm which resembles Schistosoma mansoni, a lactic acid producer, in the differential activities of the terminal enzymes of the pathway.

Chandlerella hawkingi: Glucose utilization and glycolytic enzymes

Abstract Chandlerella hawkingi, the filarial parasite of the Indian jungle crow (Corvus macrorhynchos Wagler) has been shown to utilize glucose to form mainly lactic acid. Eighty five to one hundred percent of glucose is aerobically converted into lactic acid and only 0.5% to pyruvic acid. The parasite possesses significant amounts of aldolase, triose phosphate dehydrogenase, enolase and lactate dehydrogenase activities. However, glucose-6-phosphate, 6-phosphogluconate and isocitrate dehydrogenases could not be detected in measurable amounts. From these results it is inferred that the parasite meets its energy requirement through the process of glycolysis.

Stimulation of RNA synthesis in Cicer arietinum seedlings by cyclic 3':5' adenosine monophosphate.

IAA induces tryptophan oxygenase (EC 1.13.1.12) in Cicer arietinum seedlings and CAMP mimics this action [I]. In seedlings preincubated with IAA, there is also a 3-3.5fold activation of adenyl cyclase as evident from increased incorporation of [8-14C]adenine into [14C]cAMP [2]. Furthermore, the inhibitory effect on germination of C. arietinum caused by inclusion of 8-azadenine in the imbibition medium is readily reversed by either IAA or CAMP [3]. These findings are suggestive of a regulatory role played by IAA in the early phase of seed germination. Evidence presented now demonstrates that CAMP and IAA stimulate in vitro RNA and protein synthesis in C. arietinum without affecting DNA synthesis.

Inhibition of germination in cicer arietinum

Abstract 8-Azadenine, cycloheximide, dl -ethionine and p -fluorophenylalanine inhibited the germination of Cicer arietinum . Inhibition by 8-azaadenine was reversed by either adenosine, cyclic-3′,5′-AMP or indole-3-acetic acid. Inhibition by cycloheximide was not reversible by any of the agents tested. Degradation of reserve proteins, polysaccharides and phosphates which occurred during germination was also inhibited by these agents. When seeds were exposed to inhibitors during imbibition, the induction of proteases, amylase, phosphatase and peroxidase activities that occurred during germination was inhibited, indicating that these enzymes appeared in seedlings by de dovo synthesis.

Compositional changes during the germination of cicer arietinum

Quantitative changes in the contents of protein, free amino acids, starch, polyfructosans, soluble sugars, phosphates and the activities of ten enzymes during 7 days of germination of Cicer arietinum (chick pea: Bengal gram) are reported.

Preparation of bacterial enzymes by controlled lysis

Abstract 1. 1. Lysis of Vibrio cholerae and Escherichia coli under controlled conditions by Versene and lysozyme has been adapted to separate the cells into three major fractions. 2. 2. Succinic oxidase, cytochrome oxidase and DPNH-cytochrome c reductase are located in the protoplast membrane or sediment. 3. 3. TPN linked iso -citrate, G6P dehydrogenases, DPN-linked malic dehydrogenase, aldolase, aspartic acid deaminase, adenosine deaminase, histidase and iso -citritase activities are present in the lysates of the “protoplasts” obtained by this method.

Growth inhibitory action of saccharin and cyclamate on rats receiving a poor rice diet.

1. The effect of saccharin and cyclamate on growth of young rats fed on a poor rice diet or a balanced diet was investigated. 2. Saccharin and cyclamate retarded the growth of rats on the multi-deficient diet but not of those on the well-balanced diet during an 8-week feeding period. 3. The sweeteners did not produce any macroscopic or microscopic changes in the liver, kidneys, intestines, spleen or lungs of the animals receiving the poor rice diet other than the changes resulting from the nutritional deficiency of the diet. 4. The sweeteners did not inhibit the liver xanthine oxidase activity of rats receiving the poor rice diet to an extent greater than the inhibition brought about by the deficiency of protein in the diet. 5. When given by intubation to healthy rats, the sweeteners inhibited the induction of liver tryptophan oxygenase; given in vitro, they inhibited the succinate dehydrogenase activity of rat liver mitochondria.

The anti-oxidant action of Rutin on tissue peroxidization and release of lysosomal acid phosphatase

Rutin, when administered intraperitoneally or orally, does not affect the in vitro formation of lipid peroxides by rat brain and kidney homogenates incubated aerobically. The drug, however, inhibits lipid peroxide formation when added to homogenates or tissue fractions rich in lysosomes but does not prevent the release of acid phosphatase and protein from the latter.