Strains of Caenorhabditis elegans mutant for clk-1 exhibit a 20-40% increase in mean lifespan. clk-1 encodes a mitochondrial protein thought to be either an enzyme or regulatory molecule acting within the ubiquinone biosynthesis pathway. Here CLK-1 is shown to be related to the ubiquinol oxidase, alternative oxidase, and belong to the functionally diverse di-iron-carboxylate protein family which includes bacterioferritin and methane mono-oxygenase.
P. anserina mutants with impairments in complex IV (COX) of the respiratory chain are characterized by an increase in lifespan. Examples are the nuclear grisea mutant with a moderate lifespan extension (60%) and the immortal extranuclear ex1 mutant. Here we report data demonstrating that in mutant ex1 the level of the alternative oxidase (PaAOX) is significantly higher than in mutant grisea. PaAOX levels appear to be reversely dependent on COX activity.
Centenarians are people who escaped from major common diseases, including cancer, and reached the extreme limits of human life-span. The analysis of demographic data indicates that cancer incidence and mortality show a levelling off around the age of 85-90 years, and suggests that oldest old people and centenarians are protected from cancer onset and progression.
SIGNIFICANCE: The oxidative stress theory of aging has been the most widely accepted theory of aging providing insights into why we age and die for over 50 years, despite mounting evidence from a multitude of species indicating that there is no direct relationship between reactive oxygen species (ROS) and longevity. Here we explore how different species, including the longest lived rodent, the naked mole-rat, have defied the most predominant aging theory.
American Journal of Physiology. Endocrinology and Metabolism
Xenobiotic metabolism has been proposed to play a role in modulating the rate of aging. Xenobiotic metabolizing enzymes (XME) are expressed at higher levels in calorically restricted mice (CR) and in GH/IGF-I-deficient, long-lived mutant mice. In this study, we show that many phase I XME genes are similarly upregulated in additional long-lived mouse models, including "crowded litter" (CL) mice, whose lifespan has been increased by food restriction limited to the first 3 wk of life, and in mice treated with rapamycin.
In some patients with major depressive disorder (MDD), individual illness characteristics appear consistent with those of a neuroprogressive illness. Features of neuroprogression include poorer symptomatic, treatment and functional outcomes in patients with earlier disease onset and increased number and length of depressive episodes. In such patients, longer and more frequent depressive episodes appear to increase vulnerability for further episodes, precipitating an accelerating and progressive illness course leading to functional decline.
Three pharmacological techniques for measuring inhibition of "non-specific" oxidase activity in the mouse are described: (1) potentiation of pentobarbitone hypnosis, (2) potentiation of chlorpromazine hypothermia; and (3) reduction in the toxicity of octamethylpyrophosphorodiamide (schradan). Iproniazid, isoniazid, and beta-diethylaminoethyl 3,3-diphenylpropylacetate (SKF 525A) gave comparable results in all three tests.
A 24-hr inhalation of 1,1,1-tricholoroethane (methylchloroform), 3,000 ppm, reduced pentobarbital hypnosis and increased hexobarbitaloxidation by the 9,000 x g liver supernatant fraction in male mice. On the other hand, an ip injection of methylchloroform, l ml/kg, increased the duration of pentobarbital hypnosis and reduced hexobarbital metabolism by the liver microsomal enzymes. The potentioating effect of methylchloroform on pentobarbital hypnosis as diminished when it was diluted with olive oil, but was markedly enhanced when diluted with dimethysusoxide (DMSO) before injection.