Aging is associated with a chronic oxidative stress (increase of oxidants and decrease of antioxidants), which contributes to immunosenescence and therefore shorter longevity. Nevertheless, a positive social network has been related to the adequate maintenance of health and deceleration of aging. Adult prematurely aging mice (PAM) are characterized by their inadequate stress response to a T-maze, showing premature immunosenescence and oxidative stress establishment.
View Article and Find Full Text PDFPurpose: The aim of this study was to assess the effect of local application of growth hormone on osseointegration of dental implants inserted in osteoporotic bones.
Materials And Methods: Twenty female New Zealand rabbits were used in this study. Ten were ovariectomized and fed a low-calcium diet for 6 weeks, and the others remained intact.
Growth hormone (GH) and melatonin are two hormones with quite different physiological effects. Curiously, their secretion shows parallel and severe age-related reductions. This has promoted many reports for studying the therapeutic supplementation of both hormones in an attempt to avoid or delay the physical, physiological, and psychological decay observed in aged humans and in experimental animals.
View Article and Find Full Text PDFThe connection between the innate immune system, clock genes, and mitochondrial bioenergetics was analyzed during aging and sepsis in mouse heart. Our results suggest that the sole NF-κB activation does not explain the inflammatory process underlying aging; the former also triggers the NLRP3 inflammasome that enhances caspase-1-dependent maturation of IL-1β. In this way, aged mice enter into a vicious cycle as IL-1β further activates the NF-κB/NLRP3 inflammasome link.
View Article and Find Full Text PDFAging is associated with an increase in oxidative stress and inflammation. The aging lung is particularly affected since it is continuously exposed to environmental oxidants while antioxidant machinery weakens with age. Melatonin, a free radical scavenger, counteracts inflammation and apoptosis in healthy cells from several tissues.
View Article and Find Full Text PDFAging increases oxidative stress and inflammation. Melatonin counteracts inflammation and apoptosis. This study investigated the possible protective effect of melatonin on the inflammatory and apoptotic response secondary to ischemia induced by blockade of the right middle cerebral artery (MCA) in aging male Wistar rats.
View Article and Find Full Text PDFAbstract This paper will review the effect of aging on glucose metabolism and insulin resistance in pancreas and in peripheral tissues and how melatonin administration could affect these parameters. In SAMP8 mice insulin levels in plasma were found to be increased together with enhanced HOMA-IR values, whereas insulin content in pancreas showed a decrease with aging. Aging in SAMP8 mice was also associated with a significant increase in the relative expression of both protein and mRNA of different pro-inflammatory mediators.
View Article and Find Full Text PDFEpidemiological studies indicate that certain aspects of lifestyle and genetics act as risk factors for a variety of cardiovascular disorders, including coronary disease, hypertension, heart failure and stroke. Aging, however, appears to be the major contributor for morbidity and mortality of the impaired cardiovascular system. Growth hormone (GH) and melatonin seem to prevent cardiac aging, as they contribute to the recovery of several physiological parameters affected by age.
View Article and Find Full Text PDFThe aim of this study was to determine the outcomes of oestrogen and melatonin treatments following long-term ovarian hormone depletion on neuroinflammation and apoptotic processes in dentate gyrus of hippocampi. Forty-six female Wistar rats of 22 months of age were used. Twelve of them remained intact, and the other 34 were ovariectomized at 12 months of age.
View Article and Find Full Text PDFIntroduction: Previous studies have indicated that resveratrol, a natural phytoestrogen, can act as an anti-aging therapy to resist age-related changes of several body tissues. However, the anti-aging effects of resveratrol on bone have been poorly investigated in this natural aging population. Accordingly, this study was design to evaluate the effects of resveratrol on bone mass and biomechanical properties in old rat femora.
View Article and Find Full Text PDFObjectives: The aims of this study were to identify if the associations of physical activity (PA) and muscle strength may vary throughout the ageing process; to study the differences among genders in the relationships between PA and strength in elderly people and to test whether these differences are explained by the hormonal, nutritional and inflammatory status.
Study Design: A total of 1741 people ≥65 years of age participated in this cross-sectional study.
Main Outcome Measures: Upper- and lower-limbs maximal voluntary isometric strength was obtained using standardized techniques and equipment.
Introduction: Previous studies have shown that melatonin, an anti-oxidant molecule secreted from the pineal gland, is a positive regulator of bone mass. However, the potential effects of melatonin on bone mass have never been investigated in an old population. The aim of this study was to assess the effects of dietary melatonin supplementation on mass accrual and biomechanical properties of old rat femora.
View Article and Find Full Text PDFUnlabelled: The effect of melatonin administration on age-induced alterations in hepatocytes, central nervous system, immune system, and skin are reviewed. Twenty-two-month-old Wistar rats and SAMP8 (senescence prone) mice of 10 months of age were used as experimental models. Wistar rats were analyzed untreated or after the chronic administration of melatonin at a dose of 1 mg/kg/day in the drinking water for 10 weeks.
View Article and Find Full Text PDFFatty livers occur in up to 20% of potential liver donors and increase cellular injury during the ischemia/reperfusion phase, so any intervention that could enable a better outcome of grafts for liver transplantation would be very useful. The effect of melatonin on liver ischemia/reperfusion injury in a rat model of obesity and hepatic steatosis has been investigated. Forty fa/fa Zucker rats were divided in 4 groups.
View Article and Find Full Text PDFPeptides
October 2012
Patterns of leptin secretion during the estrous cycle and the possible relationship of changes in circulating leptin during the periovulatory period with ovarian function in sows of obese (Iberian breed) and lean genotype (Large White x Landrace) were evaluated in two consecutive experiments. Plasma leptin concentrations throughout the estrous cycle in lean sows remain unchanged, but Iberian females showed a periovulatory increase in circulating leptin levels without associated changes in body condition and fatness. In these sows, plasma leptin concentrations at Days -1 and 0 of the cycle were found to be positively correlated with the ovulation rate (r=0.
View Article and Find Full Text PDFBackground: Ischemia/reperfusion (I/R) causes functional and structural damage to liver cells, this being more pronounced with increasing age of the tissue. Melatonin is a pineal indole that has been shown to play an important role as a free radical scavenger and anti-inflammatory molecule.
Material And Methods: The age-dependent responses to I/R were compared in 2-mo-old and 14-mo-old male Wistar rats.
The aim of the present study was to investigate the effect of aging on several parameters related to glucose homeostasis and insulin resistance in pancreas and how melatonin administration could affect these parameters. Pancreas samples were obtained from two types of male mice models: senescence-accelerated prone (SAMP8) and senescence-accelerated-resistant mice (SAMR1). Insulin levels in plasma were increased with aging in both SAMP8 and SAMR1 mice, whereas insulin content in pancreas was decreased with aging in SAMP8 and increased in SAMR1 mice.
View Article and Find Full Text PDFThis study has investigated the effect of aging on parameters of inflammation, oxidative stress and apoptosis in pancreas obtained from two types of male mice models: senescence-accelerated prone (SAMP8) and resistant mice (SAMR1). Animals of 2 (young) and 10 months of age (old) were used (n = 64). The influence of the administration of melatonin in the drinking water for one month at two different dosages (1 and 10mg/(kg day) on old SAMP8 mice on these parameters was also studied.
View Article and Find Full Text PDFHorm Mol Biol Clin Investig
October 2011
Aging of the brain causes important reductions in quality of life and has wide socio-economic consequences. An increase in oxidative stress, and the associated inflammation and apoptosis, could be responsible for the pathogenesis of aging associated brain lesions. Melatonin has neuroprotective effects, by limiting the negative effects of oxygen and nitrogen free radicals.
View Article and Find Full Text PDFAging is associated with an increase in inflammation, oxidative stress, and apoptosis. Furthermore, aging is accompanied by an alteration of the growth hormone (GH) -insulin-like growth factor-1 (IGF-1) axis. The aim of this study was to examine the regulation of these parameters in the pancreas of old mice and how GH treatment could affect this process.
View Article and Find Full Text PDFPurpose: The achievement of primary stability in porous and soft bone, where implants are more likely to fail, is one of the unresolved challenges of implant dentistry. Therefore, the aim of the study was to validate an osteoporotic animal model for analysis of poor-quality bone.
Materials And Methods: Sixteen female New Zealand rabbits, each 6 months old and weighing 4 to 5 kg, were used in this study.
Calcium sensitization is an important physiological process in agonist-induced contraction of smooth muscle. In brief, calcium sensitization is a pathway that leads to smooth muscle contraction independently of changes in [Ca(2+)](i) by mean of inhibition of myosin light chain phosphatase. Aging has negative impacts on gallbladder contractile response due to partial impairment in calcium signaling and alterations in the contractile machinery.
View Article and Find Full Text PDFWe assessed whether melatonin administration would prevent the hyperoxidative status that occurs in lung mitochondria with age. Mitochondria from lungs of male and female senescent prone mice at 5 and 10 months of age were studied. Age-dependent mitochondrial oxidative stress was evaluated by measuring the levels of lipid peroxidation and nitrite, glutathione/glutathione disulfide ratio, and glutathione peroxidase and reductase activities.
View Article and Find Full Text PDFLow mitochondriogenesis is critical to explain loss of muscle function in aging and in the development of frailty. The aim of this work was to explain the mechanism by which mitochondriogenesis is decreased in aging and to determine to which extent it may be prevented by exercise training. We used aged rats and compared them with peroxisome proliferator-activated receptor-γ coactivator-1α deleted mice (PGC-1α KO).
View Article and Find Full Text PDF