Search results for "Melatonin"

Biochemical and molecular basis involved in the synthesis of melatonin and other derivatives of aromatic amino acids in Saccharomyces cerevisiae

2021

Recientemente, el metabolismo de los aminoácidos aromáticos en levaduras se ha relacionado con la síntesis de moléculas bioactivas (melatonina, serotonina, tirosol, hidroxitirosol, etc...) que podrían ser relevantes desde diferentes aspectos relacionados tanto con la regulación de las levaduras como con la salud humana. Las actividades de estos compuestos como potenteantioxidante y otros aspectos beneficiosos para la salud del consumidor hacen que sea realmente interesante estudiar su síntesis. Sin embargo, se conoce poca información sobre la síntesis de estas moléculas bioactivas por la levadura porque es un tema de estudio muy reciente. Por tanto, la hipótesis de trabajo de la presente te…

Il trattamento dell’insonnia in eta’ evolutiva: report clinico e revisione della letteratura

2014

Efficacy of three drugs for protecting against gentamicin-induced hair cell and hearing losses

2012

BACKGROUND AND PURPOSEExposure to an ototoxic level of an aminoglycoside can result in hearing loss. In this we study investigated the otoprotective efficacy of dexamethasone (DXM), melatonin (MLT) and tacrolimus (TCR) in gentamicin (GM)-treated animals and cultures.EXPERIMENTAL APPROACHWistar rats were divided into controls (treated with saline); exposed to GM only (GM); and three GM-exposed groups treated with either DXM, MLT or TCR. Auditory function and cochlear surface preparations were studied. In vitro studies of oxidative stress, pro-inflammatory cytokine mRNA levels, the MAPK pathway and caspase-3 activation were performed in organ of Corti explants from 3-day-old rats.KEY RESULTSD…

Inhibition of Melatonin in the Plasma of Third-Generation Male Mice under the Action of ELF Magnetic Fields

1998

The pineal gland has been considered a magnetic receptor organ that regulates circadian rhythms by means of the secretion of melatonin, a potent oncostatic agent that prevents the initiation and promotion of cancer. ELF electromagnetic radiation, similar to that generated by power lines, can alter melatonin plasma levels.To study this effect, 4 OF1 mice generations have been reared subjected to a lifelong 15 μT, 50 Hz magnetic field action. This magnetic field was generated inside a Helmholtz coil system. The concentration of melatonin in the blood has been determined on 40 male mice of the third generation by means of RIA, as they reached sexual maturity (3 months).A radical decrease, more…

Beneficial Effect of Melatonin on Blastocyst In Vitro Production from Heat-Stressed Bovine Oocytes

2013

Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10(-12) , 10(-9) , 10(-4)  m; Experiment 4: 0, 10(-3)  m), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and …

The phototransduction cascade in the isolated chick pineal gland revisited.

2003

It is well established that the isolated chick pineal gland is directly light sensitive and that melatonin synthesis of the gland can be inhibited by exposing the gland to light during scotophase. Since not all the steps of the phototransduction cascade have been clarified to the same extent as in the retina, we have treated isolated chick pineal glands with 90 min of light during scotophase and with drugs that affect key-components of vertebrate phototransduction, i.e., cyclic guanosine monophosphate (cGMP) phosphodiesterase 6 (PDE6), cGMP levels and cGMP-gated calcium channels. The endpoint measured was the activity of the rate-limiting enzyme of melatonin synthesis, arylalkylamine N-acet…

Electrical responses of homing pigeon and guinea pig Purkinje cells to pineal indoleamines applied by microelectrophoresis

1984

The effects of microelectrophoretically applied melatonin (aMT), 5-methoxytryptophol (ML), 5-hydroxytryptophol (HL) and noradrenaline (NA) on the electrical activity of cerebellar Purkinje and other cells during both day- and nighttime were studied in urethane-anesthetized intact and pinealectomized homing pigeons and guinea pigs.

Clorgyline effect on pineal melatonin biosynthesis in adrenalectomized rats pretreated with 6-hydroxydopamine

1994

The response to administration of the specific monoamine oxidase A (MAO-A) blocker clorgyline was investigated in adult male Sprague-Dawley rats which were adrenalectomized four days prior to treatment or were additionally sympathectomized as newborns by injection of 6-hydroxydopamine. In both groups, the contents of pineal indoles melatonin and N-acetylserotonin were augmented, and the contents of 5-hydroxyindoleacetic acid and 5-hydroxyindoletryptophol decreased 90 min following clorgyline injections when compared to rats receiving saline. The observed responses were less pronounced in rats both adrenalectomized and sympathectomized. The results are in line with the hypothesis that preser…

Gas-phase ion chemistry of protonated melatonin

2005

The gas-phase ion chemistry of protonated melatonin has been investigated by mass spectrometric (MS) techniques involving chemical ionisation, fast atom bombardment and electrospray ionisation. Either naturally- occurring or collision-induced decomposition e-D derivatives obtained by exchange with D(2)O. The analysis of experimental results allows definite pathways for the formation of the ion at m/z 174 to be assigned and sheds some more light on the overall fragmentation pathways. Experiments on labelled derivatives evidenced H-D scrambling processes during fragmentation

Papel del la melatonina en la capacidad antioxidante total del calostro y leche humana madura. Diferencias entre parto vaginal y parto por cesárea

2021

OBJETIVOS: La tasa de cesáreas electivas se ha incrementado las últimas décadas, lo cual, puede tener importantes repercusiones perinatales. Nuestro objetivo fue determinar si el tipo de parto influye en el contenido en melatonina en leche materna, la principal hormona reguladora de los ritmos circadianos, así como en la capacidad antioxidante de la leche materna. METODOLOGIA: Se incluyeron 21 mujeres que parieron vía vaginal, y 17 mujeres que parieron por cesárea electiva. Se excluyeron madres y neonatos con patología. Se recolectaron dos muestras de leche materna (una diurna y otra nocturna) en tres etapas de la lactancia: calostro, leche de transición, leche madura. Se analizó el conteni…