Abstract:
:The rod outer segment (ROSg) membranes are essentially lipoprotein complexes. Rhodopsin, the major integral protein of ROSg, is surrounded by phospholipids highly enriched in docosahexaenoic acid (22:6 n3). This fluid environment plays an important role for conformational changes after photo-activation. Thus, ROSg membranes are highly susceptible to oxidative damage. Melatonin synthesized in the pineal gland, retina and other tissues is a free radical scavenger. The principal aim of this work was to study the changes in the ROSg membranes isolated from bovine retina submitted to nonenzymatic lipid peroxidation (ascorbate-Fe2+ induced), during different time intervals (0-180 min). Oxidative stress was monitored by increase in the chemiluminescence and fatty acid alterations. In addition we studied the in vitro protective effect of 5 mm melatonin. The total cpm originated from light emission (chemiluminescence) was found to be lower in those membranes incubated in the presence of melatonin. The docosahexaenoic acid content decreased considerably when the membranes were exposed to oxidative damage. This reduction was from 35.5 +/- 2.9% in the native membranes to 12.65 +/- 1.86% in those peroxidized during 180 min. In the presence of 5 mm melatonin we observed a content preservation of 22:6 n3 (23.85 +/- 2.77%) at the same time of peroxidation. Simultaneously the alterations of membrane proteins under oxidative stress were studied using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Loss of protein sulfhydryl groups and increased incorporation of carbonyl groups were utilized as biomarkers of protein oxidation. In membranes exposed to Fe2+ -ascorbate, we observed a decrease of protein thiols from 50.9 +/- 3.38 in native membranes to 1.72 +/- 2.81 nmol/mg of protein after 180 min of lipid peroxidation associated with increased incorporation of carbonyl groups into proteins from 7.20 +/- 2.50 to 12.50 +/- 1.12 nmol/mg of protein. In the SDS-PAGE we observed a decrease in the content of all the proteins, mainly rhodopsin, as a consequence of peroxidation. Melatonin, prevent both lipid peroxidation and protein oxidation.
journal_name
J Pineal Resjournal_title
Journal of pineal researchauthors
Guajardo MH,Terrasa AM,Catalá Adoi
10.1111/j.1600-079X.2006.00352.xsubject
Has Abstractpub_date
2006-10-01 00:00:00pages
201-10issue
3eissn
0742-3098issn
1600-079Xpii
JPI352journal_volume
41pub_type
杂志文章abstract::A link between endotoxemia and nonalcoholic fatty liver disease (NAFLD) has been demonstrated in human and rodent animals. Nevertheless, the molecular mechanisms of endotoxin-evoked NAFLD remain poorly understood. We hypothesize that reactive oxygen species (ROS) mediate lipopolysaccharide (LPS)-evoked hepatic lipid a...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2011.00905.x
更新日期:2011-11-01 00:00:00
abstract::There are functional inter-relationships between the beta cells of the endocrine pancreas and the pineal gland, where the synchronizing circadian molecule melatonin originates. The aim of this study was to elucidate a putative interaction between insulin and melatonin in diabetic patients and a diabetic rat model. We ...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2005.00287.x
更新日期:2006-03-01 00:00:00
abstract::To examine the role of melatonin in pathological hyperprolactinemia we compared untreated young females (N = 5) with hyperprolactinemic amenorrhea owing to pituitary microadenoma to healthy female controls (N = 6). Serum samples for melatonin, prolactin, and luteinizing hormone (LH) concentrations were obtained every ...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1996.tb00242.x
更新日期:1996-03-01 00:00:00
abstract::Melatonin is found in a wide variety of plant species. Several investigators have studied the physiological roles of melatonin in plants. However, its role is not well understood because of the limited information on its biosynthetic pathway. To clarify melatonin biosynthesis in plants, we isolated a cDNA-coded arylal...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2009.00673.x
更新日期:2009-05-01 00:00:00
abstract::The effect of melatonin injection on Freund's adjuvant-induced changes in levels and 24-hr rhythms of circulating ACTH, growth hormone (GH), prolactin (PRL), luteinizing hormone (LH), and insulin was assessed in rats. Animals received subcutaneous (s.c.) injections of melatonin (30 microg) or vehicle, 1 hr before ligh...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1999.tb00592.x
更新日期:1999-08-01 00:00:00
abstract::The circadian clock plays a vital role in physiology and behavior such as the sleep-wake cycle and blood pressure and hormone levels. Immune responses also display circadian rhythmicity and particularly pineal melatonin contributes to immunological processes. Little attention, however, is given to mechanisms underlyin...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/jpi.12230
更新日期:2015-05-01 00:00:00
abstract::The effects of melatonin (3 mg/kg i.p.) and the melatonin receptor agonist S-20098 (3 mg/kg i.p.) on the vigilance states, electroencephalogram power spectra (0.25-25.0 Hz), and cortical temperature were determined in eight rats in the first 6-hr interval of the 12-hr light period. Compared to the vehicle injection bo...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1994.tb00078.x
更新日期:1994-01-01 00:00:00
abstract::In the present research, we studied the effect of the administration of melatonin or S-adenosyl-L-methionine (S-AMe) on oxidative stress and hepatic cholestasis produced by double ligature of the extra-hepatic biliary duct (LBD) in adult male Wistar rats. Hepatic oxidative stress was evaluated by the changes in the am...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1034/j.1600-079x.2001.280303.x
更新日期:2000-04-01 00:00:00
abstract::Glaucoma may be associated with circadian disruption due to its association with a loss of intrinsically photosensitive retinal ganglion cells. Clinical evidence demonstrating an association between glaucoma and circadian disruption is limited, and no large-scale studies have been performed. The purpose of this cross-...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/jpi.12662
更新日期:2020-09-01 00:00:00
abstract::Atherosclerosis (AS) is an inflammatory disease linked to endothelial dysfunction. Melatonin is reported to possess substantial anti-inflammatory properties, which has proven to be effective in AS. Emerging literature suggests that pyroptosis plays a critical role during AS progression. However, whether pyroptosis con...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/jpi.12449
更新日期:2018-03-01 00:00:00
abstract::GPR50 is an orphan seven transmembrane protein related to the melatonin receptor subfamily comprising MT(1) and MT(2) receptors. In the absence of any known ligand for GPR50, other tools are critical for the characterization of this protein. Here, we describe the generation, purification and characterization of the fi...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2007.00437.x
更新日期:2007-08-01 00:00:00
abstract::Human placental mitochondria might be a significant source of NADPH- and iron-dependent production of reactive oxygen species (ROS). Preeclampsia is believed to be a consequence of overproduction of ROS in human placenta. The experimental results presented here show that melatonin inhibits NADPH- and iron-dependent li...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2010.00779.x
更新日期:2010-09-01 00:00:00
abstract::The purpose of this study was to determine whether melatonin treatment would mitigate retinal ganglion cell (RGC) death in the developing retina following a hypoxic insult. Lipid peroxidation (LPO), glutathione (GSH), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) concentrations, expression of vascular end...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/jpi.12016
更新日期:2013-03-01 00:00:00
abstract::The association of seasonal changes in health and disease has been known for centuries. The prevalence of psychopathological symptoms with seasonal fluctuations and the use of melatonin as a biological marker of circadian and circannual rhythms is well documented. The aim of this work was to study the variability of m...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2006.00365.x
更新日期:2006-10-01 00:00:00
abstract::Melatonin, a potent antioxidant, has shown to be beneficial in murine Venezuelan equine encephalomyelitis (VEE) virus infection. In addition, melatonin can induces the production of interleukin-1 beta (IL-1beta), a cytokine capable of inducing increased expression of inducible nitric oxide synthase; the activity of th...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2006.00381.x
更新日期:2007-03-01 00:00:00
abstract::The role played by postsynaptic alpha-adrenergic receptors in the stimulation of pineal melatonin production was investigated in the Syrian hamster. The studies were conducted using organ cultured pineal glands collected from both anatomically intact and superior cervical ganglionectomized hamsters. Results obtained i...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1989.tb00437.x
更新日期:1989-01-01 00:00:00
abstract::Melatonin, a major pineal secretory product, exerts a range of physiological and neuroprotective effects. However, the functional significance of melatonin in determining neural identity, and the mechanisms by which this may occur, is unknown. In this study, P19 cells were used as a model system and cell behavior was ...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/jpi.12153
更新日期:2014-09-01 00:00:00
abstract::Aging is accompanied by changes in the morphology and physiology of organs and tissues, such as the liver. This process might be due to the accumulation of oxidative damage induced by reactive oxygen (ROS) and reactive nitrogen species (RNS). Hepatocytes are very rich in mitochondria and have a high respiratory rate, ...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2006.00385.x
更新日期:2007-01-01 00:00:00
abstract::We investigated the role of melatonin on water avoidance stress (WAS)-induced degeneration of the gastric, ileal and colonic mucosa. Wistar albino rats were exposed to acute WAS (aWAS group) or chronic WAS (cWAS group). Before exposing animals to acute (aWAS + mel group) or chronic WAS (cWAS + mel group), 10 mg/kg mel...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2004.00143.x
更新日期:2004-09-01 00:00:00
abstract::The presence of melatonin and the enzymes (transcripts and activities) involved in its synthesis, i.e. arylalkylamine N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), was investigated in the eggs and early embryos of Japanese quail at Hamburger-Hamilton stages 1-10. Melatonin was present in ...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2007.00421.x
更新日期:2007-04-01 00:00:00
abstract::A decrease in nocturnal serum melatonin levels was reported in patients with clinically uncharacterized coronary artery disease. To assess whether there was a correlation between melatonin production and disease stage, we measured the nocturnal urinary excretion of 6-sulphatoxymelatonin (an index of blood melatonin co...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1034/j.1600-079x.2000.290302.x
更新日期:2000-10-01 00:00:00
abstract::The effect of melatonin (0.1 microM) on freshly isolated islets from adult rats was investigated. Melatonin caused a marked decrease of insulin secretion by islets in response to glucose. The mechanism involved was then examined. Melatonin did not interfere with glucose metabolism as indicated by the measurement of gl...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1034/j.1600-079x.2002.02903.x
更新日期:2002-10-01 00:00:00
abstract::Four-week-old male hamsters, born and raised in total darkness or in LD 14:10 (hr) were exposed to several low levels of illumination for 14 weeks. Analyses showed that testicular weights were significantly affected by both photic history and illuminance levels. Animals born in the dark possessed larger testes than th...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1985.tb00641.x
更新日期:1985-01-01 00:00:00
abstract::A study was carried out to determine the possible influence of melatonin on the proliferation of Kirkman-Robbins hepatoma cells in Syrian hamsters, both in vivo and in vitro. A highly significant inhibition of the proliferation of transplanted hepatoma cells was observed in vivo following melatonin administration (pro...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1992.tb00063.x
更新日期:1992-10-01 00:00:00
abstract::Thrombocytopenia is a frequent complication of cancer and constitutes an absolute contraindication for chemotherapy. Recent studies have demonstrated that platelet generation may be influenced by both cytokines and neurohormones. In particular, the pineal indole melatonin has been proven to enhance platelet number in ...
journal_title:Journal of pineal research
pub_type: 临床试验,杂志文章
doi:10.1111/j.1600-079x.1999.tb00579.x
更新日期:1999-04-01 00:00:00
abstract::The present study analyzes the participation of pineal stalk and superior cervical ganglia (SCG) in the conduction of photic evoked potentials (PEP) to the pineal body (PB) in unanesthetized freely moving rats implanted with semimicroelectrodes. The PEPs were recorded in PB, lateral hypothalamus (LH), and habenular co...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1987.tb00866.x
更新日期:1987-01-01 00:00:00
abstract::Melatonin has shown particular promise as a neuroprotective agent to prevent motoneuron death in animal models of both amyotrophic lateral sclerosis (ALS) and spinal cord injuries (SCI). However, an understanding of the roles of endogenous melatonin receptors including MT1, MT2, and orphan G-protein receptor 50 (GPR50...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2012.01022.x
更新日期:2013-01-01 00:00:00
abstract::A review of the literature indicates that the absolute oral bioavailability of exogenous melatonin in humans or in preclinical animal models has not been adequately characterized; hence, this study was undertaken. Pharmacokinetics of melatonin was studied in rats, dogs, and monkeys following intravenous and oral admin...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1997.tb00302.x
更新日期:1997-01-01 00:00:00
abstract::Maternal hyperthermia induces early embryonic death via increased oxidative stress to the embryo. In this study, we examined whether melatonin administered to heat-stressed pregnant mice would reduce hyperthermia-induced embryonic death. Mice were heat stressed (12 hr at 35 degrees C, 60% relative humidity) on the day...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079X.2005.00260.x
更新日期:2005-10-01 00:00:00
abstract::The permeability of the pineal gland to lanthanum was investigated by means of transmission electron microscopy and X-ray microanalysis. Different pineal cell populations were studied. Light pinealocytes as well as glial cells were not permeated by the tracer lanthanum, which normally stays extracellularly. Dark pinea...
journal_title:Journal of pineal research
pub_type: 杂志文章
doi:10.1111/j.1600-079x.1992.tb00031.x
更新日期:1992-03-01 00:00:00