http://www.jbc.org/content/250/14/5475.full.pdf

Purification and characterization of the flavoenzyme glutathione reductase from rat liver.

Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer

Resume Au cours des quinze dernieres annees l'attention s'est beaucoup plus portee sur les enzymopathies hereditaires du globule rouge entrainant une anemie hemolytique que sur les deficits enzymatiques erythrocytaires non responsables d'une maladie hematologique. Dans cette derniere categorie, l'anomalie erythrocytaire constitue un indicateur precieux soit d'un deficit enzymatique generalise, soit de l'impact des modifications d'environnement sur le metabolisme intra-erythrocytaire. Le diagnostic de plusieurs enzymopathies sans retentissement hematologique peut etre aisement etabli par l'etude des globules rouges : c'est le cas de la galactosemie (deficit en galactose-1-phosphate uridyl transferase), du deficit en galactokinase, du deficit en hypoxanthine-guanine phosphoribosyltransferase et de l'acatalasemie. L'identification des heterozygotes est egalement possible. Pour la galactosemie, un depistage systematique a la naissance est realisable par l'etude d'un echantillon de sang seche sur papier filtre. Les anomalies nutritionnelles peuvent retentir sur l'equipement enzymatique erythrocytaire et conduire a un diagnostic errone d'enzymopathie hereditaire. L'exemple le plus frappant est celui du deficit en glutathion-reductase. Cette anomalie a longtemps ete consideree comme hereditaire. En fait, bien qu'une certaine variabilite genetique essentiellement decelable par electrophorese existe, la plupart des cas decrits correspondent a un deficit acquis, que l'on peut corriger in vitro par l'addition de FAD ou in vivo par l'administration de riboflavine. De meme l'activite de la transaminase glutamo-oxalo-acetique erythrocytaire depend de l'apport quotidien en pyridoxine. L'administration d'acide nicotinique multiplie par 10 le taux du NAD dans les globules rouges. Le bleu de methylene ou la diaminodiphenyl sulfone augmentent le glutathion erythrocytaire. La teneur en 2,3 diphosphoglycerate des globules rouges depend du taux d'hemoglobine et du pH sanguin. La connaissance et la comprehension de l'effet des variations de l'environnement sur les enzymes et le metabolisme erythrocytaires permettent d'envisager le traitement de certaines maladies metaboliques hereditaires. Nous avons essaye de traiter par l'acide nicotinique deux subets atteints d'anemie hemolytique congenitale ou spherocytaire due a un deficit en G6PD. Malgre l'absence de resultats positifs, il est permis d'esperer que sous une autre forme, une telle approche therapeutique puisse s'averer plus efficace.

Red cell metabolism

Products, requirements and efficiency of biosynthesis: a quantitative approach

Publisher Summary This chapter reviews oxygen poisoning and X-irradiation. Exposure to unphysiologically high tensions of oxygen causes irreversible damage to living matter. The problem of oxygen toxicity is important in clinical medicine and in deep-sea diving. A consideration of various isolated reports leads to the hypothesis that oxygen poisoning and the primary action of X-irradiation have a common basis of action: possibly the formation of the oxidizing free radicals OH, and O2H, and H2O2. The evidence of a protective effect of coenzyme A against X-rays and against oxygen toxicity in experiments is incomplete and needs further studies. The chapter presents a table reporting the effect of X-rays and protective agents on oxygen poisoning in mice.

https://science.sciencemag.org/content/sci/119/3097/623.full.pdf

Oxygen Poisoning and X-irradiation: A Mechanism in Common

A study on keratin

http://www.jbc.org/content/112/1/361.full.pdf

Derivatives of keratin

The reduction of glutathione by plant tissues.

The heat activation of Neurospora tetrasperma ascospores is a reversible process, since activated spores may be returned to secondary dormancy by preventing respiration, and these secondarily dormant spores may be induced to germinate by reheating. Activation of the spores brings about a large increase in respiration prior to the germination of the spores. As the spores are reversibly activated or deactivated the rate of respiration is increased or is decreased. By poisoning the cells with iodoacetamide it is possible to prevent all germination without greatly inhibiting this increase in respiration. Precisely with the beginning of germination a secondary rise in respiration occurs. The respiration of the spores is cyanide sensitive. The heat activation has a critical temperature at about 49 to 52°C.; and at a constant temperature within this range, the percentage of the spores activated as plotted against the time, follows an S-shaped population curve.

/pdf/the-reversible-heat-activation-inducing-germination-and-47sqao51h2.pdf

David R. Goddard

Papers

A study on keratin

Derivatives of keratin

The reduction of glutathione by plant tissues.

The reversible heat activation inducing germination and increased respiration in the ascospores of neurospora tetrasperma.

Physical Chemistry of Cells and Tissues.