The Aging Kidney—As Influenced by Heavy Metal Exposure and Selenium Supplementation

Abstract

The aging process in the kidneys has been well studied. It is known that the glomerular filtration rate (GFR) declines with age in subjects older than 50–60 years. However, there is still insufficient knowledge regarding the response of the aged kidney to environmental toxicants such as mercury, cadmium, and lead. Here, we present a review on the functional decline and proposed mechanisms in the aging kidney as influenced by metal pollutants. Due to the prevalence of these toxicants in the environment, human exposure is nearly unavoidable. Further, it is well known that acute and chronic exposures to toxic metals may be detrimental to kidneys of normal adults, thus it may be hypothesized that exposure of individuals with reduced GFR will result in additional reductions in renal function. Individuals with compromised renal function, either from aging or from a combination of aging and disease, may be particularly susceptible to environmental toxicants. The available data appear to show an association between exposure to mercury, cadmium and/or lead and an increase in incidence and severity of renal disease in elderly individuals. Furthermore, some physiological thiols, as well as adequate selenium status, appear to exert a protective action. Further studies providing improved insight into the mechanisms by which nephrotoxic metals are handled by aging kidneys, as well as possibilities of therapeutic protection, are of utmost importance.

Serum Protein α-Klotho Mediates the Association between Lead, Mercury, and Kidney Function

“…Among various metals, blood lead has been linked to blood homocysteine (48), an amino acid involved in oxidative stress and aging. Blood lead and blood mercury can affect kidney function through excessive production of ROS ( 49) and cause damage or apoptosis of renal tubular epithelial cells by destroying the balance of the oxidative stress system and heme oxygenase activity (9). Oxidative stress is considered an important mechanism of metal damage to renal function.…”

“…Previous studies have shown (8) that heavy metals can promote the production of reactive oxygen species (ROS), oxidative stress, and kidney cell damage. Some researchers believe (9) that heavy metals can cause damage or apoptosis of renal tubular epithelial cells by destroying the oxidative stress system and in ammatory response-the balance of heme oxygenase activity, impairing renal tubular reabsorption and ultimately leading to Decreased kidney function. Therefore, oxidative stress is an essential mechanism of metal damage to renal function (10)(11)(12)(13)(14)(15)(16).…”

Stimuli responsive gelation of tert-butylacetic acid based LMOGs – applications in remediation of marine oil spills, dye removal and heavy metal sensing

“…Mercury poisoning can cause hearing loss, gait abnormality, ataxia, erosive bronchitis, respiratory insufficiency, tremor, excitability (also known as mercurial erethism), loss of memory, insomnia, excessive salivation, tunnel vision, oxidative stress, kidney damage, lipid peroxidation and liver impairment. 23–26…”

“…Mercury poisoning can cause hearing loss, gait abnormality, ataxia, erosive bronchitis, respiratory insufficiency, tremor, excitability (also known as mercurial erethism), loss of memory, insomnia, excessive salivation, tunnel vision, oxidative stress, kidney damage, lipid peroxidation and liver impairment. [23][24][25][26] There is increasing interest in reducing the heavy metal concentration in aqueous medium using low molecular weight gelators. In some cases, the use of metal ions can trigger the formation of metallogels which can be useful in sensing as well as reducing their concentration.…”

Toxic and Essential Metals in Human Health and Disease 2021

“…Aaseth et al [ 12 ], in a review, underscore the insufficient knowledge regarding the response of the aged kidney to environmental toxicants such as cadmium, mercury, and lead, and present proposed mechanisms of the aged kidney to metal pollutants. Human exposure to these toxicants is practically unavoidable in our industrialized society, and it may be hypothesized that exposure of individuals with reduced GFR will result in additional reductions in renal function.…”