Comparison And A Contrast On Toxins That Affect Various Body Systems (Essay Sample)

Compare and Contrast Toxins
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Introduction
Toxins are basically proteins that are poisonous and are produced by living cells. These substances have capability to cause diseases if ingested but also have the ability to trigger neutralizing antitoxins (Ito & Yoshida, 2014). This paper is intended to do a comparison and a contrast on toxins that affect various body systems more specifically, the cardiovascular system, the nervous system and the endocrine system. The toxins that will be studied are mercury, ethanol and botulinum. Characteristics shared by these toxins will be identified and an insight will be provided on the characteristics that make these toxins vulnerable to toxicity of the specific systems that they affect.
Botulinum toxin and the nervous system
Botulinum neurotoxins (BoNTs) are formed by anaerobic, spore-forming, gram-positive rod bacteria known as Clostridium botulinum, that occur mostly on plants, in the intestinal tracts of animals, in water and in the soil (Popoff & Poulain, 2013). The seven serologically distinct botulinum neurotoxins (BoNT/A-G) mainly affect the peripheral nervous system in humans causing a persistent and often fatal neuroparalytic syndrome known as botulism.
Unless injected into the muscles during treatment, exposure to botulinum neurotoxins is either through in vivo (production of the toxin by C. botulinum in the intestines) or through oral ingestion of preformed toxins in food or water, (Popoff & Poulain, 2013). The toxins then cross the digestive mucosa through transcytosis into the blood stream and extracellular fluid where they target motor neuron endings. The botulinum neurotoxins block the release of acetylcholine, the main neurotransmitter, from the presynaptic motor neurons at the neuromuscular junctions by degrading the SNARE proteins necessary for acetylcholinevesicle-membrane fusion. This interferes with neural transmission causing flaccid paralysis (Popoff & Poulain, 2013).
This specificity of action displayed by botulinum neurotoxins has made them invaluable as therapeutic agents in treating numerous human neurological syndromes caused by cholinergic nerve terminals hyper activity (Popoff, M. R., &Poulain, B, 2010).
Ethanol and the endocrine system
With respect to the National Institute of Environmental Health Sciences (NIH) and also referring to Turner (2015), endocrine disruptors mess about with the organism’s endocrine system causing unpleasant neurological, developmental, reproductive and immune effects in human beings. One potent endocrine toxin is ethanol.
When absorbed in the body, ethanol and other endocrine disruptors alter hormonal functions in a number of ways. They may alter the natural production of hormones or mimic hormones in the body such as thyroid hormones, androgens or estrogen and cause overstimulation. They may also attach to hormone receptors and block endogenous hormones from binding (Turner, 2015).
Mercury and cardiovascular system
Mercury is both a natural and synthetic contaminant. It exists in many forms from organic mercury in contaminated fish and wild animals to inorganic mercury in vapor and products such as medication. Human exposure occurs via a number of ways, which together with the chemical form of the mercury at the time of exposure determines its toxic potential, (Ito & Yoshida, 2014).
The nervous system is the principal repository for mercury toxins but their transitory and residual systemic circulation affects other organs (Ito & Yoshida, 2014). Significant exposure to the cardiovascular system is associated with symptoms of lower heart rate, fatigue, chest pains, elevated blood pressure and a high potential for blood clots this is because the mercury impairs the cardiac electrical and neurotransmitter function, lowers red blood cell and hemoglobin levels in the blood and causes damage to the heart valves and blood vessels. Accumulation in the heart may result in cardiomyopathy.
Mercury works by binding to thiol sites in living tissues of the cardiovascular system. By attaching to the thiol sites in hemoglobin, the oxygen carrying capacity of RBCs is reduced resulting in hypoxia. Mercury also binds to the thiol protein in the acetylcholine and the heart muscle receptor consequently blocking the vagus nerve electrical impulses for contraction from reaching the heart muscle.
According to Ito and Yoshida, (2014) when dying, red blood cells exposed to mercury toxin release proteins that encourage the clumping together of the red blood cells and platelets inside the blood vessels a condition called thrombosis that increases the risk of cardiovascular disease.
Characteristics shared by the toxins that make that make them toxic to specific systems
With reference to Turner (2015), the specificity of these toxins to the specific systems they attack is attributed to their mode of action. Botulinum, ethanol and mercury toxins share a number of characteristics. Most notable one is their neurotoxic ability. Neurotoxins work by inhibiting neuron cellular processes so these three neurotoxins are classified according to what they inhibit. Botulinum toxin is classified as a synaptic vesicle release inhibitor. Mercury, especially in the form of methylmercury, diethylmercury or dimethylmercury, is classified as a blood brain barrier inhibitor since it restricts the transportation of glutamate and amino acids which has potential excitotoxic effects, (Turner, 2015). Lastly, ethanol is classified among neurotoxins with multiple effects. Among the known effects are; induced inflammation in the brain, widespread brain atrophy and reduced neurogenesis in the hippocampus, which is ...