Trivalent (arsenite) and pentavalent (arsenate) arsenic produce different effects on cells, yet there is little distinction between the two forms of arsenic when discussing signs and symptoms of poisoning. An important fact to note is that during the metabolism of arsenate, 50-70% of it will be reduced to arsenite in the first step of the process. Therefore, the differences in the cell effects are seen from the 30-50% of the pentavalent arsenic unchanged via the bioactivation step of oxidizing glutathione or enzymatically catalyzed by arsenate reductase.1,2 The mentioning of the high amounts of arsenite formed from arsenate is important. This is because, arsenite is much more rapidly taken up by hepatocytes,2 which are the most predominant
Arsenic is rapidly cleared from the body and often is undetectable after only a few hours. However, continuous exposure to arsenic can result in severe poisoning and multiple organ involvement. Arsenic is one of the most common pollutants and contamination of food and water is widespread and consumption is significant. Recent studies have linked a correlation between dermatofibromas and arsenic. One study suggested that the combination of dermatofibromas and arsenic caused the development of breast cancer. However, the exact cause in development of dermatofibroma is unknown but damage to the endothelial cells is commonly caused by arsenic exposure. Instead of the arsenic being excreted in eccrine glands, arsenic becomes deposited in a concentrated area of the body and built over a period of time causes the growth and development of
Arsenic has been shown to cause cancer and deaths. However, the element is multifaceted because in other studies it has been shown to have a healing effect. Be that as it may, the component is clearly exceptionally equivocal in light of the fact that in different reviews it has been appeared to have a recovering impact.
Previous research has pointed out that the mechanism by which arsenic exerts its toxic effect is through impairment of cellular respiration by the inhibition of various mitochondrial enzymes, and the uncoupling of oxidative phosphorylation. Most toxicity of arsenic results from its ability to interact with sulphydryl groups of proteins and enzymes, and to substitute phosphorous in a variety of biochemical reactions
Hepatocytes are involved in synthesizing proteins, cholesterol, bile salts, fibrinogen, phospholipids and glycoproteins. Additionally, hepatocytes ensure that our
Many laboratory studies have shown that acrylamide causes a variety of tumors in rats and mice. When male and female rats were given 3.0mg/kg bw/day acrylamide in drinking water for two years, the incidence of tumors increased in scrotum, adrenal, thyroid, mammary, oral cavity, and uterus. However, there is no definite evidence that acrylamide produces tumors in humans. Acrylamide has been classified by the US EPA as a B2, a probable human carcinogen, by IARC (International Agency for Research on Cancer) as a 2B, a possible human carcinogen, and by ACGIH (American Conference of Industrial Hygienists) as an A3, confirmed animal carcinogen with unknown relevance to humans.
While nitrates are one of the major contaminants in the area, San Joaquin Valley residents face drinking water pollution from many other sources including arsenic, coliform bacteria, and pesticides. Arsenic is a naturally occurring semi-metal element that is found in different types of rocks. While arsenic primarily occurs naturally, human activities impact the amount of arsenic in groundwater. Arsenic is not only toxic at high concentrations, but also harmful after prolonged exposure at moderately elevated levels. California recognizes arsenic as a human carcinogen and believes prolonged exposure to the element to be associated with various cancers, including skin, bladder, kidney, lung, and liver cancers. A study in Maine found a connection between water contaminated
Copper is another pollutant that at very high levels is toxic and can cause vomiting, diarrhea, loss of strength or, for serious exposure, cirrhosis of the liver (Pure Water Services). In order for copper to metabolized the heavy metal zinc is needed. Zinc helps with copper breakdown but too much zinc can cause a copper deficiency which can also cause problems such as anemia. While copper has some severe side effects there have not been any cases that are related to cancer. In most cases throughout the Silver Bow Creek copper is not thought to be a severe threat to the community.
In the respiration phase, citrate helps increase the intake of oxygen while slowing down the releasing of carbon dioxide as shown in Table I. Glycogen, hexosediphosphate, alpha-glycerophosphate increases the effect of the respiration phase helping support that carbohydrates are the substrates that are catalyzed by the citrate in the pigeon muscles. Next, the researchers examined the rate of disappearance of citric acid and found that the poisons arsenite or malonate make the citric acid in the muscle disappear in large groups if oxygen is present, but they do not affect the breakdown of citric acid. Table III shows the effect that arsenite has on the citric acid of the pigeon muscle. Researchers then looked at the conversion of citric acid to alpha-ketogluteric acid by using methylene blue to oxidize citric acid because neither poisons could fully oxidize citric acid (Table IV). The oxidation of the citric acid (malonate), is then checked by being placed in succinic acid, which identified succinic and alpha- ketogluteric acid by measuring the pressure of the fluid in a column or manometrically. To see if the synthesis of citric acid is true, the researchers must find out if citric acid can be regenerated through one of the products made through oxidation. The pigeon muscle was able to generate citric acid in the presence of oxaloacetic acid; however, the other intermediates including pyruvic acid
It was shown in section 3.5 that Azide – 2 significantly inhibited the growth of all three cell types: 4T1 – RLR, HT1080 – luc2 and HepG2 – luc2. Azide – 2 which was shown as the most potent competitor of glutamine uptake tested in this study also killed the cells with IC50 values at 0.1 – 0.2mM. As previously mentioned, only a very low concentration of Azide – 2 from 5 - 16µM was effective enough to reduce the glutamine uptake by these cell types to a half of maximal level. The mechanism by which the cell growth was disrupted quickly is still unclear. However, the extreme interference of glutamine uptake should be the first point to exploit the action of Azide – 2. Then, more experiments can be subsequently carried out to investigate the killing effect on the intracellular environment. In contrast to Azide – 2, Azide – 1 killed the cells slowly with the IC50 value at 0.55 – 3mM which is 5 – 30 fold higher than that of Azide – 2. The mode of Azide – 1’s toxicity to cells is quite consistent with the inhibition trend of glutamine uptake. As Azide – 1 bound and inhibited the glutamine uptake by 4T1 – RLR and HepG2 – luc2 cells better than HT1080 – luc2 cells, it affects the growth of the former two cell types more dramatically than the latter. Hence, the working mechanism on which the compound counted to
Humans are primarily exposed to mercury through the consumption of freshwater and marine animals that have accumulated methylmercury in their fatty tissues 4. Mercury is absorbed in gastrointestinal (GI) tissues through dietary consumption. From the GI tract, mercury enters surrounding tissues and the blood stream where it can be transported throughout the body 8. The health consequences of mercury are resultant of the intracellular binding of organelles essential for cellular function 3. Thus, mercury exposure at a cellular level can cause cellular degradation and eventual
Of the liver enzymes that showed elevations in their serum concentrations following irradiation in the current study, only the early increase in the AST level was significant (Fig. 9). ALT is also a marker of hepatic damage, and it is found exclusively in the cytoplasm of cells. In contrast, AST is present in the cytoplasm, which comprises 20% of its total activity, and in the mitochondria, which comprises 80% of its total activity (Rej 1989). While the recruited granulocytes and the gamma irradiation could damage some periportal hepatocytes, irradiation treatment may have a more damaging effect on the numerous large mitochondria that reside within the hepatocytes, which would lead to a greater
Many animal studies have shown that lead is capable of causing oxidative stress in many organs (Patra et al., 2001). Toxicity of lead is mainly attributed to the induction of oxidative stress by disruption of the pro-oxidant/anti-oxidant balance, elevation of reactive oxygen and nitrogen species (ROS and RNS, respectively) such as superoxide radicals, hydrogen peroxide, hydroxyl radicals and lipid peroxides, and nitric oxide (Kumar and Reddy, 2012). Currently, N-acetyl-L-cysteine (NAC), derives from L-Cysteine and the precursor of glutathione (GSH), is a well-established cyto-protective drug against drugs induced hepatotoxicity and nephrotoxicity (Whyte et al., 2007; Akbulut et al., 2014), where it exerts antioxidant properties. L-Cysteine was utilized as a chelator of heavy metal to conserve against oxidative stress and inhibit damage to cells and tissues. L-cysteine, a sulfur-containing amino acid, is a nutritionally occurring non-essential amino
Professor Chris Exley, a world famous aluminium expert, had hoped the inquest would highlight just how little we know about the safety of one of the most prolific metals on the planet. Prof Exley has explained that aluminium, added to nearly everything we eat, drink, inject and absorb is classed as a neurotoxin at high levels. Yet despite this, no one actually knows whether the amount of aluminium we’re ingesting is a safe amount. In spite of hundreds of publications demonstrating that the aluminum isn’t safe, there haven’t been any real investigations into the subject of aluminium accumulation in the body. Exley, a professor of Inorganic Chemistry at Keele University, Staffordshire, has been researching the subject of aluminium for over a quarter of a century.
There has been a collection of environmental chemicals that have been implicated in ASD development such as: arsenic, lead, manganese, mercury, pesticides, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) polycyclic aromatic hydrocarbons (PAHs) and solvents (Dietert et al,
ALP was released in India as a rodenticide at first. (2,3).This substance next to the water ,water stream or gastric acid produces a non –color, fire caching, with fish-stench like smell called phosphine(PH3) that is cause of intoxication. phosphine is a protoplasmic poison which leads to a non –competitive inhibition of cytochrome oxidase enzyme in mitochondria ,electrons transfer system and oxidative phosphorylation. Hence to the production of free radicals in several tissues by phosphine, those organs which need more oxygen like heart, brain, lungs, kidney and liver have more sensitivity to phosphine related damages and this in association with histopathological changes in those organs(4 ).The toxicity is due to reaction of emissions with air humidity, and the presence of hydrochloric acid. (3, 5)The current dose of ALP in an adult with the average weight of 70 kg is estimated about 500mg(4).Rice