Activity of Glutathione Peroxidase, Glutathione Reductase, and Lipid Peroxidation in Erythrocytes in Workers Exposed to Lead

Abstract

The aim of this study was to estimate the activity of glutathione peroxidase (GPx), glutathione reductase (GR), and malondialdehyde (MDA) in erythrocytes in healthy male employees of zinc and lead steelworks who were occupationally exposed to lead over a long period of time (about 15 yr). Workers were divided into two subgroups: the first included employees with low exposure to lead (LL) (n=75) with blood lead level PbB=25-40 microg/dL and the second with high exposure to lead (HL) (n=62) with PbB over 40 microg/dL. Administration workers (n=35) with normal levels of PbB and zinc protoporphyrin in blood (ZPP) in blood were the control group. The activity of GPx significantly increased in LL when compared to the control group (p<0.001) and decreased when compared to the HL group (p=0.036). There were no significant changes in activity of GR in the study population. MDA erythrocyte concentration significantly increased in the HL group compared to the control (p=0.014) and to the LL group (p=0.024). For the people with low exposure to lead (PbB=25-40 microg/dL), the increase of activity of GPx by about 79% in erythrocytes prevented lipid peroxidation and it appears to be the adaptive mechanism against the toxic effect of lead. People with high exposure to lead (with PbB over 40 microg/dL) have shown an increase in MDA concentration in erythrocytes by about 91%, which seems to have resulted from reduced activity of GPx and the lack of increase in activity of GR in blood red cells.

Effect of Lead (Pb) Exposure on the Activity of Superoxide Dismutase and Catalase in Battery Manufacturing Workers (BMW) of Western Maharashtra (India) with Reference to Heme biosynthesis

“…Lead induced decrease concentration of hemoglobin (Hb) in blood of BMW group in present study supported this view. A few indices of erythropoietic activity like PCV, MCH and MCHC were significantly decreased in lead exposed BMW group and also corroborate the same view.Most of the research findings observed that lead increased concentration of lipid peroxide in blood, both in experimental or clinical studies [41,42]. It was reported that increase level of lipid peroxide in plasma is associated with decrease erythrocyte-SOD and erythrocyte-Catalase activities in the workers who were occupationally exposed to lead (mean Pb-B concentration is 57.1+17.6 µg/dL) [12].…”

Oxidative damage to proteins related to metals and antioxidant defenses in breastmilk

“…); the difference was attributed to the Cd present in the cigarette (38). Moreover, it has been reported an increase in the activity of GPx (79%) related to low concentrations of Pb (p < 0.001) in human erythrocytes, the opposite occurs at high concentrations of Pb, thus there is a relationship between this element and activity of GPx (39). If the concentration of Pb and Cd affects the activity of GPx, this can interfere with its antioxidant action, increasing the risk of protein oxidation by ROS.…”

The effects of lead and zinc ion exposure on the antioxidant status of mice liver

“…According to scientific sources, Pb treatment caused significant decreases, both in liver and brain GSH levels, for young and adult Pb-exposed groups when compared with their control ones. The levels of oxidized glutathione (GSSG) in all samples (liver, brain, and erythrocytes) were higher in Pb-exposed groups as compared with their controls [24][25][26]. Under oxidative stress, GSSG is reduced to GSH by glutathione reductase (GR), an indirect component of the antioxidant defense system.…”