Alterations in isoforms of glutathione S-transferase in liver and kidney of cadmium exposed rhesus monkeys: purification and kinetic characterization

Dual enzyme activities assay by quantitative electrospray ionization quadrupole-time-of-flight mass spectrometry

A practical and rapid method based on electrospray ionization quadrupole-time of flight mass spectrometry (ESI-Q-ToF MS) was developed for detecting activities of both acetylcholinesterase IAChEI and glutathione S-transferase (GST). The simultaneous study of these two enzyme activities is significant for studying human bio-functions, especially for those who take in toxic compounds and have a risk of disease. Here, the enzyme activities were represented by the conversion of enzymatic substrates and determined by quantitatively analyzing enzymatic substrates. Different internal standards were used to quantify each enzymatic substrate and the good linearity of calibration curves demonstrated the feasibility of the internal standards. The Michaelis-Menten constants (Km) of both GST and AChE were measured by this method and were consistent with values previously reported. Furthermore, we applied this approach to detect GST and AChE activities of whole bloods from four deceased and healthy people. The variation in enzyme activity was in accord with information from gas chromatography mass spectrometry [GC/MS). The screening of AChE and GST provided reliable results and strong forensic evidence. This method offers an alternative choice for detecting enzyme activities and is anticipated to have wide applications in pharmaceutical research and prevention in toxic compounds.

Effects of exposure to a mixture of cadmium and chromium on detoxification enzyme (GST, P450-MO) activities in the frog Rana ridibunda

The effect of two heavy metals, namely chromium and cadmium, on GST and P450-MO activities in the liver, kidney and gut of the frog Rana ridibunda, and the use of these detoxification enzyme systems as possible markers of heavy metal contamination of rivers in Northern Greece was investigated. In control animals, the highest P450-MO activity was observed in the liver and the lowest activity in the gut. As regards GST, the liver and kidneys showed the highest activity. Exposure of Rana to either Cr or a mixture of Cr and Cd caused a decrease in liver GST and P450-MO and renal GST activities. An important finding was that both GST and P450-MO activities were negatively correlated with concentrations of both metals in the liver of mixture-exposed animals. The results suggest that the determination of GST and P450-MO activities, in combination, could serve to indicate heavy metal contamination in rivers of Northern Greece.

A comparative evaluation of the biological effects of environmental cadmium-contaminated control diet and laboratory-cadmium supplemented test diet

This study was designed to examine the effects of a diet contaminated by environmental cadmium on organ/body weight ratio and selected toxicological indices. It was also designed to permit a comparative analysis of the effects of the diet contaminated by environmental cadmium and that of cadmium supplemented diet based on the same parameters. Our results show that even though the cadmium content of the environmental cadmium contaminated diet was 300% less than that of the cadmium supplemented diet, the former caused statistically significant changes in Superoxide dismutase (SOD) activity (P < 0.025), Na+/K+ ATPase activity (P < 0.005) and Malondialdehyde (MDA) level (P < 0.025) when values at the end of 1 month exposure were compared to the values at the end of 3 months exposure. These parameters were altered in the same manner by the cadmium content of the supplemented diet in addition to significant reduction in liver/body weight ratio (P < 0.005) within the exposure periods examined. By virtue of the very close nature of the values of these parameters in rats exposed to the two different diets, it appears that the background cadmium (cadmium from the environment) content of the diets is largely responsible for the observed changes, except in the case of liver/body weight ratio.

Cadmium-induced time-dependent oxidative stress in liver of mice: a correlation with kidney

In the present investigation a time-responsive oxidative stress, both in liver and kidney were carried out following cadmium (Cd) exposure. Cadmium was administered subcutaneously on each other day in normal saline solution. Mice were sacrificed on the 15th, 30th and 45th days post-exposure. For oxidative stress study different biochemical markers, e.g. lipid peroxidation (LPO), reduced glutathione (GSH) and glutathione S-transferase (GST) activity were considered. Time-responsive exponential increase in the lipid peroxidation and decrease in glutathione level and glutathione S-transferase activity occurred both in hepatic and renal tissues following cadmium treatment. Though both the organs responded in a similar fashion, their magnitude of response was found to be different. Body weight did not differ but relative liver and kidney weight were found to be significantly increased at different time points. The possible mechanism of time-dependent cadmium-induced toxic effects and relation between hepatic and renal biochemical response have been discussed.