Modulation by pineal gland of ouabain high-affinity binding sites in rat cerebral cortex

Castroviejo, Darío Acuña; Castillo, J. L.; Fernández, Begoña; Gomar, María Dolores; Aguila, Carmen María del

doi:10.1152/ajpregu.1992.262.4.r698

Cited by 14 publications

(15 citation statements)

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“…Special care was taken to avoid environmental stress before and during the course of the experiments. Mice were pinealectomized under Equithesin anesthesia [28]. Animals were active within 30 min after the operation, and they were studied 6 days after surgery.…”

Section: Methodsmentioning

confidence: 99%

Circadian Rhythms of Dopamine and Dihydroxyphenyl Acetic Acid in the Mouse Striatum: Effects of Pinealectomy and of Melatonin Treatment

et al. 2002

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The existence of dopamine (DA)-melatonin (aMT) relationships is well documented in several brain areas of the mammalian central nervous system such as the retina and hypothalamus or the nigrostriatal system. For instance, aMT tempers 1 methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nigrostriatal damage in C57BL/6 mice. In this mouse strain however, rhythmic production of aMT and its possible interaction with striatal DA is still unclear. In the present work we investigated circadian variations in pineal production of aMT and striatal DA levels in C57BL/6 mice. Effects of pinealectomy and aMT administration were also assessed. Intact, pinealectomized and pinealectomized + aMT-treated mice and their respective control groups were sacrificed at six different times during the 24-hour period. In control animals, aMT displayed a circadian rhythm with a narrow peak at midnight. The peak of aMT coincided with the nadir of the DA rhythm present in the striatum. Shortly after the decrease of DA levels, an increase in 3,4-dihydroxyphenylacetic acid (DOPAC), the main DA metabolite, was observed. The rhythmic changes of DA and DOPAC levels in the striatum were blunted by pinealectomy, whereas administration of aMT (0.1–10 mg/kg) during 6 days to pinealectomized mice restored the rhythms in a dose-dependent manner. Striatal levels of 3-methoxytyramine and homovanillic acid did not change during the 24-hour cycle. The serotonergic system, assessed by the determination of 5-hydroxytryptamine and 5-hydroxyindole-3-acetic acid concentration in striatum, did not show significant time-dependent changes in control animals and was not affected by pinealectomy or aMT treatment. These data substantiate the existence of a link between pineal function, melatonin secretion and DA circadian rhythm in the mouse striatum.

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Section: Methodsmentioning

confidence: 99%

Circadian Rhythms of Dopamine and Dihydroxyphenyl Acetic Acid in the Mouse Striatum: Effects of Pinealectomy and of Melatonin Treatment

et al. 2002

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“…Melatonin (N-acetyl-5-methoxytryptamine), the main metabolite of the methoxyindole pathway, displays neuroprotective capacities against convulsive episodes in humans (4-7) and in experimental animals (8)(9)(10). Melatonin inhibits brain excitability, regulating both g-aminobutyric acid and benzodiazepine receptors and Na þ , K þ -ATPase activity (11)(12)(13). A relationship between melatonin, corticotrophic and opioid peptides and brain benzodiazepine receptors has been also reported (14,15).…”

Section: Introductionmentioning

confidence: 93%

Comparison between tryptophan methoxyindole and kynurenine metabolic pathways in normal and preterm neonates and in neonates with acute fetal distress

Muñóz-Hoyos

Molina-Carballo²,

Macías³

et al. 1998

European Journal of Endocrinology

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Objective: To analyze the kynurenine and methoxyindole metabolic pathways of tryptophan in order to identify changes in premature neonates and in neonates suffering from fetal distress. Methods: One hundred and twelve neonates were assigned to three groups: normal neonates (control group), preterm neonates (neonates born before the 37th gestational week) and neonates suffering from fetal distress. Each of these groups was then divided in two subgroups according to the time of birth corresponding with the time of blood sampling: a diurnal subgroup, comprising neonates whose blood was sampled between 0900 and 2100 h, and a nocturnal subgroup, comprising neonates whose blood was sampled between 2100 and 0900 h. Blood samples from the umbilical artery and vein were taken in the delivery room at birth from each neonate for measurement of melatonin, the main methoxyindole pathway metabolite. Urine samples were collected from 0900 to 2100 h (diurnal groups) and from 2100 to 0900 h (nocturnal groups), and the presence of kynurenic acid, xanturenic acid, 3-hydroxyantranilic acid, L-kynurenine and 3-hydroxykynurenine determined. Results:The results show the existence of diurnal/nocturnal differences in the concentration of melatonin in cord blood and in the urinary excretion of kynurenines. In normal neonates, the production of methoxyindoles (determined as melatonin) is decreased during the day and increases at night, whereas production of kynurenines is high during the day, decreasing at night. In the fetal distress group, a significant increase in the umbilical artery concentration of melatonin was found. This group also showed a reduction in L-kynurenine concentrations in the diurnal and nocturnal groups, and an increase in xanturenic acid and 3-hydroxyantranilic acid during the day. Correlation and regression studies confirmed that the differences in the day/night pattern of the tryptophan metabolic pathways were greater in normal neonates than in the preterm and fetal distress groups. Conclusions:The results indicate the existence of an imbalance in tryptophan metabolites in preterm infants and those with fetal distress, blunting the normal diurnal/nocturnal rhythm of both melatonin and kynurenines. European Journal of Endocrinology 139 89-95

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“…Anticonvulsant activity of melatonin was initially shown to be related to its effects on both brain GABA-benzodiazepine receptor complex and Na + , K + -ATPase activity [103][104][105][106][107]. However, due to the inhibitory effect of melatonin on the NOS/NO system, an effect of the indoleamine on glutamate-induced excitotoxicity was soon proposed.…”

Section: Melatonin and Mitochondrial Pathologymentioning

confidence: 99%

Melatonin, Mitochondrial Homeostasis and Mitochondrial-Related Diseases

Castroviejo¹,

Escames²,

Carazo³

et al. 2002

CTMC

141

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The recently described 'hydrogen hypothesis' invokes metabolic symbiosis as the driving force for a symbiotic association between an anaerobic, strictly hydrogen-dependent organism (the host) and an eubacterium (the symbiont) that is able to respire, but which generates molecular hydrogen as an end product of anaerobic metabolism. The resulting proto-eukaryotic cell would have acquired the essentials of eukaryotic energy metabolism, evolving not only aerobic respiration, but also the cost of oxygen consumption, i.e., generation of reactive oxygen species (ROS) and oxidative damage. Mitochondria contain their own genome with a modified genetic code that is highly conserved among mammals. Control of gene expression suggests that transcription of certain mitochondrial genes may be regulated in response to the redox potential of the mitochondrial membrane. Mitochondria are involved in energy production and conservation, and they have an uncoupling mechanism to produce heat instead of ATP. Also, mitochondria are involved in programmed cell death. Increasing evidence suggests the participation of mitochondria in neurodegenerative and neuromuscular diseases involving alterations in both nuclear (nDNA) and mitochondrial (mtDNA) DNA. Melatonin is now known as a powerful antioxidant and increasing experimental evidence shows its beneficial effects against oxidative stress-induced macromolecular damage and diseases, including those in which mitochondrial function is affected. This review summarizes the data and mechanisms of action of melatonin in relation to mitochondrial pathologies.

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Modulation by pineal gland of ouabain high-affinity binding sites in rat cerebral cortex

Cited by 14 publications

References 0 publications

Circadian Rhythms of Dopamine and Dihydroxyphenyl Acetic Acid in the Mouse Striatum: Effects of Pinealectomy and of Melatonin Treatment

Circadian Rhythms of Dopamine and Dihydroxyphenyl Acetic Acid in the Mouse Striatum: Effects of Pinealectomy and of Melatonin Treatment

Comparison between tryptophan methoxyindole and kynurenine metabolic pathways in normal and preterm neonates and in neonates with acute fetal distress

Melatonin, Mitochondrial Homeostasis and Mitochondrial-Related Diseases

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