Likars'ka Sprava / Ministerstvo Okhorony Zdorov'ia UkraÔny
Telomeres are the ends of chromosomes and are non-coding DNA "end-capped" with structures containing DNA-quadruplexes and proteins. Telomeres become shorter after each cell division, which is one of the mechanisms of gradual ageing. Telomerase is the reverse transcriptase responsible for the extension of telomere length. It is well known that activation of telomerase in the most types of organism's cells is not enough for telomere length stabilization. The reason may be in the telomere "caps", which cover telomere ends from telomerase action.
Aging is characterized by accumulation of potentially harmful altered proteins that could lead to gradual deterioration of cellular functions and eventually result in increased probability of death. Metabolic turnover of proteins thus plays an essential role in maintaining the life of an organism. In this article we summarize our current knowledge on age-related changes in protein turnover with special reference to degradation. Increase in half-life of proteins with advancing age is well documented.
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
Insulin-like growth factor (IGF)-1 signaling might partly mediate effects of caloric restriction (CR), an experimental intervention for increasing longevity in mammals. The present study evaluated effects of recombinant human (rh)IGF-1 infusion on adipokine levels in CR and transgenic (Tg) dwarf rats with the reduced growth hormone-IGF-1 axis, which shared similar body weight and food intake. At 9 months of age, each rat received a continuous infusion of rhIGF-1 for 14 days, and rats received an injection of glucose after overnight fasting.
Caloric restriction (CR) slows the aging process and extends longevity, but the exact underlying mechanisms remain debatable. It has recently been suggested that the beneficial action of CR may be mediated in part by adipose tissue remodeling. Mammals have two types of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). In this study, proteome analysis using two-dimensional gel electrophoresis combined with MALDI-TOF MS, and subsequent analyses were performed on both WAT and BAT from 9-month-old male rats fed ad libitum or subjected to CR for 6 months.
It is known that a global decrease in food ingestion (dietary restriction, DR) lowers mitochondrial ROS generation (mitROS) and oxidative stress in young immature rats. This seems to be caused by the decreased methionine ingestion of DR animals. This is interesting since isocaloric methionine restriction in the diet (MetR) also increases, like DR, rodent maximum longevity.
Maillard reaction contributes to the chemical modification and cross-linking of proteins. This process plays a significant role in the aging process and determination of animal longevity. Oxidative conditions promote the Maillard reaction. Mitochondria are the primary site of oxidants due to the reactive molecular species production. Mitochondrial proteome cysteine residues are targets of oxidative attack due to their specific chemistry and localization. Their chemical, non-enzymatic modification leads to dysfunctional proteins, which entail cellular senescence and organismal aging.
Growth hormone & IGF research: official journal of the Growth Hormone Research Society and the International IGF Research Society
OBJECTIVE: Since a reduction of the insulin/IGF-1 signaling cascade extends life span in many species and IGF-1 signaling might partly mediate the effects of caloric restriction (CR), an experimental intervention for increasing longevity, the purpose of the present study was to use quantitative trait loci (QTL) analysis, an unbiased genetic approach, to identify particular regions of the genome influencing plasma IGF-1 levels in an F2 intercross between F344 and LOU/C rats; the latter being an inbred strain of Wistar origin, considered as a model of healthy aging since it resists to age (an
The effects of chronic administration of the calcium channel antagonist verapamil on the anesthetic effects of a novel specific alpha 2-receptor agonist (dexmedetomidine) were studied in rats. It is presumed that this agonist acts on both pre- and postsynaptic alpha 2-adrenoceptors. To determine whether the central postsynaptic receptors are involved in the anesthetic interactions between these drugs, rats were treated with DSP-4 to deplete endogenous norepinephrine. Loss of the righting reflex was used to determine the presence of anesthesia and the duration of hypnosis.
Following in vivo treatment with carrageenan, sex-related differences in alteration of hepatic drug metabolism were found in the rat. In adult male rats, marked decreases were observed in hepatic 9000 x g supernatant cytochrome P-450 content and in the biotransformation of hexobarbital, aminopyrine, ethylmorphine, and meperidine. Hexobarbital hypnosis was significantly prolonged by carrageenan treatment in intact and testectomized animals as compared to their respective controls.
1-(2-benzothiazolyl)-1-aryl-3-phenyl-4-arylguanidines (I-X) were prepared by oxidation of 1,3-diarylthioureas. The compounds were screened for their analgesic and hypnotic activities in rats. Of these, p-methyl group substituted compound of the series was the most potent analgesic as compared to other compounds of the series. In hypnotic test all the compounds potentiated pentobarbitone-induced hypnosis.