Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. CVDs were responsible for approximately 31% of all global deaths in 2016, and 85% of all CVD deaths are due to heart attack and stroke. The underlying process in the blood vessels that results in heart attack and stroke is atherosclerosis. A recent study indicated that exposure to environmental toxic heavy metals is associated with an increased risk of CVDs. In this review, we focus on several heavy metals as environmental risk factors for CVDs: arsenic, lead, cadmium, mercury, chromium and iron. The pathological contribution of these heavy metals to the alternation of two molecular mechanisms: the renin angiotensin aldosterone system (RAAS) and oxidative stress has been discussed. The etiology of heavy metal-induced CVDs is viewed from the perspective of RAAS and oxidative stress. The significance of environmental improvement for better health will also be considered.
Glutathione S-transferases (GSTs) belong to a group of multigene detoxification enzymes, which defend cells against oxidative stress. Tannery workers are at risk of oxidative damage that is usually detoxified by GSTs. This study investigated the genotypic frequencies of GST Mu1 (GSTM1) and GST Theta1 (GSTT1) in Bangladeshi tannery workers and healthy controls followed by their status of oxidative stress and total GST activity. Of the 188 individuals, 50.0% had both GSTM1 and GSTT1 (+/+), 12.2% had GSTM1 (+/−), 31.4% had GSTT1 (−/+) alleles, and 6.4% had null genotypes (−/−) with respect to both GSTM1 and GSTT1 alleles. Among 109 healthy controls, 54.1% were double positive, 9.2% had GSTM1 allele, 32.1% had GSTT1 allele, and 4.6% had null genotypes. Out of 79 tannery workers, 44.3% were +/+, 16.8% were +/−, 30.5% were −/+, and 8.4% were −/−. Though the polymorphic genotypes or allelic variants of GSTM1 and GSTT1 were distributed among the study subjects with different frequencies, the differences between the study groups were not statistically significant. GST activity did not vary significantly between the two groups and also among different genotypes while level of lipid peroxidation was significantly higher in tannery workers compared to controls irrespective of their GST genotypes.
Background
Plasma renin can predict future cardiovascular events as well as the prevalence of chronic renal disease in hypertensive subjects. Ovine angiotensinogen (oANG) is a better substrate for measuring renin concentration through activity assay. Recombinant oANG expressed in
Escherichia coli
cells can be utilized as the substrate while measuring plasma renin. We aim to establish an immunoassay for measuring renin concentration at picomolar level using recombinant oANG.
Material and methods
Recombinant oANG was expressed in
E. coli
cells and purified to homogeneity. Various concentrations (0–1.5 pM) of recombinant human renin standard were prepared and incubated with recombinant oANG. Renin activity was determined by angiotensin-I specific enzyme-linked immunosorbent assay.
Results
About 4.5 mg of purified recombinant oANG was obtained from 0.5 L of
E. coli
culture. The Michaelis constant and turnover number of human renin with recombinant oANG were 0.16 μM and 0.51 s
−1
, respectively. A linear relationship was obtained when renin activity was plotted as a function of renin concentration using recombinant oANG as the renin substrate. Picomolar amounts of renin can be measured from known renin activity using this method.
Conclusion
This study established a novel assay system for measuring renin at picomolar level using cost effective recombinant oANG.
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