Increase of Enzyme Activities following the in vitro Peroxidation of Normal Human Red Blood Cells

Abstract

Red blood cells (RBCs) from 15 normal human blood samples were incubated with different concentrations of hydrogen peroxide in sodium azide, and the effects of the peroxidation on several glycolytic and nucleotidic enzyme activities were investigated. The release of malonyl dialdehyde (MDA) and methemoglobin formation were used as indicators of RBC peroxidation. The increase of H(2)O(2), final concentration from 0.1 to 5 mmol/1, resulted in a progressive rise of almost all glycolytic enzyme activities, especially those of aldolase (200% of normal at 1 mmol/1), phosphoglycerate kinase (140%), phosphoglycerate mutase (136%), pyruvate kinase (130%) and glutathione peroxidase (130%), and in a decrease of glucose-6-phosphate dehydrogenase (68%) and pyrimidine-5-nucleotidase (23%). The addition of ß-mercaptoethanol to the incubation medium abolished only the effect of 1 mmol/1 H(2)O(2) on glucose-6-phosphate dehydrogenase.

Pyrimidine 5′-Nucleotidase Acquired Deficiency in Beta-Thalassaemia: Involvement of Enzyme-SH Groups in the Inactivation Process

“…Although the evidence presented by David et al [1] strongly confirms our results, no mention has been made of our paper, published in Enzyme one year ago [2], In our opinion, the results of David et al [1] stress the fact that P5N-SH groups are more sensi tive to 4-hydroxynonenal than to other aldehydes, but neither the importance of these compounds in p-thal assaemia nor their possible in vivo effect on P5N activity has been elucidated. Conversely, they are in accordance with the different effect of in vitro peroxi dation observed on pyruvate kinase activity when compared to P5N and adenylate kinase activities [2], which showed partial recovery after the addition of P-mercaptoethanol to the RBC incubation medium containing H2O2.…”

Impact of Vanadium Complexes Treatment on the Oxidative Stress Factors in Wistar Rats Plasma

“…The FRAP assay gives fast, reproducible results with plasma, with single antioxidants in pure solution and with mixtures of antioxidants in aqueous solution and was used for calibration added to plasma. On the basis of investigations presented by Russo et al [26], the relationships of vanadium probably do not cause increased concentration of peroxides of lipids, which are natural substrata of this enzyme [26–28]. In the studied animals' plasma, the decrease of GPx activity occurred.…”

Selenium and Human Health: Witnessing a Copernican Revolution?

“…Firstly, it should be noted, that prooxidant activity of Se was shown to cause upregulation of Se-independent antioxidant enzymes, such as catalase and superoxide dismutase, in different biological systems, and these observations come from plants [169,170], yeast [171], fish [172][173][174][175][176] and, importantly, human cancer cell lines [50,177]. Secondly, such adaptive stress response, specifically with respect to Se-containing enzymes, is also well known to occur following acute and chronic injury 29 human studies [178][179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196] showing that selenoproteins (including GPx and Sepp1) are upregulated in the response to oxidative stress from their baseline levels without any change in Se supply and availability, i.e. as a consequence of adaptive response [168].…”