Environmental Lead Exposure, Catalase Gene, and Markers of Antioxidant and Oxidative Stress Relation to Hypertension: An Analysis Based on the EGAT Study

Abstract

Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28 μg/dL) compared to normotensive (4.41 μg/dL) and prehypertensive (4.55 μg/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06 μg/dL and 9.67 μmol/L) than those with CC genotype (5.32 μg/dL and 8.31 μmol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension.

Maternal protein restriction induced‐hypertension is associated to oxidative disruption at transcriptional and functional levels in the medulla oblongata

“…Thus, we suggest that dysfunction between ROS and antioxidant capacity may be more pronounced in the ventral medulla, which contributes, in part, to the development of sympathetic overactivation and hypertension observed in rats exposed to protein restriction during pregnancy and lactation. Interestingly, clinical studies have shown that lipid peroxidation (MDA levels) is augmented in blood of patients with essential hypertension, and at the same time, SOD and CAT activities are reduced in these patients …”

“…Interestingly, clinical studies have shown that lipid peroxidation (MDA levels) is augmented in blood of patients with essential hypertension, and at the same time, SOD and CAT activities are reduced in these patients. 40,41 Previous studies have suggested that oxidative stress in the dorsal medulla (or specifically in nucleus tractus solitarii), it may be associated with hypertension model in which there depression of the baroreflex. 14 Interestingly a recent study demonstrated that the hypertension in rat offspring subjected to perinatal protein malnutrition is not related to the baroreflex dysfunction.…”

Hubungan Kadar Timbal Dalam Darah Dengan Tekanan Darah Pada Tenaga Kerja Di Karoseri Semarang

“…Paparan timbal kadar rendah yang terkait dengan stres oksidatif dan defisiensi enzim katalase dapat berkontribusi terhadap hipertensi. 33 Menurut penelitian Araujo M dan Wilcox S.C, stres oksidatif ginjal dapat menjadi penyebab, konsekuensi, atau lebih sering menjadi faktor potensi untuk hipertensi. Peningkatan spesies oksigen reaktif (ROS) di ginjal telah dilaporkan di beberapa kasus hipertensi yang terkait dengan vasokonstriksi ginjal, perubahan fungsi ginjal dan pelepasan renin.…”

Chronic lead exposure enhances the sympathoexcitatory response associated with P2X4 receptor in rat stellate ganglia

“…Lead exposure disturbs cardiac autonomic function, which result in hypertension and cardiovascular disease . Our data indicated that the systolic blood pressure, diastolic blood pressure and heart rate of the rats exposed to lead for 1 year increased, and the increase in a dose‐dependent manner with the lead concentration.…”