Betreff: aging & oxygen toxicity..(note Alz & Parkinsons)Reiter...1997

Von: JCMPelican

Datum: Thu, 14 Jun 2007 01:51:38 EDT


Aging and oxygen toxicity: Relation to changes in melatonin




Springer Netherlands


0161-9152 (Print) 1574-4647 (Online)


Volume 20, Number 4 / October, 1997





Subject Collection

Biomedical and Life Sciences

SpringerLink Date

Wednesday, May 31, 2006


Russel J. Reiter1


Department of Cellular and Structural Biology, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas, 78284-7762

Abstract:    Melatonin (N-acetyl-5-methoxytryptamine) is a chemical mediator produced in the pineal gland and other sites in the body. The melatonin found in the blood is derived almost exclusively from the pineal gland. Since the pineal synthesizes melatonin primarily at night, blood levels of the indole are also higher at night (5–15 fold) than during the day. Some individuals on a nightly basis produce twice as much melatonin as others of the same age. Throughout life, the melatonin rhythm gradually wanes such that, in advanced age, melatonin production is usually at a minimum.


 Melatonin was recently found to be a free radical scavenger and antioxidant. It has been shown, in the experimental setting, to protect against both free radical induced DNA damage and oxidative stress-mediated lipid peroxidation. Pharmacologically, melatonin has been shown to reduce oxidative damage caused by such toxins as the chemical carcinogen safrole, carbon tetrachloride, paraquat, bacterial lipopolysaccharide, kainic acid, δ-aminolevulinic and amyloid β peptide of Alzheimer’s disease as well as a model of Parkinson’s disease involving the drug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).


 Additionally, the oxidative damage caused by agents such as ionizing radiation and excessive exercise is reduced by melatonin. Since free radical-induced molecular injury may play a significant role in aging, melatonin’s ability to protect against it suggests  a  potential  function  of  melatonin  in  deferring  aging  and  age-related, free radical-based diseases. Besides its ability to abate oxidative damage, other beneficial features of melatonin may be important in combating the signs of aging; these include melatonin’s immune-stimulating function, its sleep-promoting ability, its function as an anti-viral agent, and general protective actions at the cellular level. Definitive tests of the specific functions of physiological levels of melatonin in processes of aging are currently being conducted.

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 [   Emphasis added by Joanne Mueller....6-13-07....   ]