Diurnal rhythms in norepinephrine and acetylcholine synthesis of sympathetic ganglia, heart and adrenals of aging rats: Effect of melatonin

Garcı́a-Bonacho, Manuel; Esquifino, Ana I.; Cardinali, Daniel P.

doi:10.1016/s0165-1838(98)00134-9

Cited by 31 publications

(28 citation statements)

References 37 publications

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“…The effect of melatonin injection could be exerted at any stage of the pathway connecting the retina with the superior cervical ganglia, or on the ganglia and/or the pineal sympathetic nerves themselves. Since melatonin treatment of old rats readily augmented NE synthesis at the neuronal perikarya located in the superior cervical ganglia [22] and only exhibited a weak restoring effect on sympathetic nerve terminals located in the pineal gland, a presynaptic change only cannot explain the age-related modifications of pineal 5-HT turnover reported herein.…”

Section: Discussionmentioning

confidence: 66%

“…Whether the changes are presynaptic or depend on intrapineal mechanisms cannot be presently ascertained. Age-dependent decreases in amplitude and mesor of 24-hour rhythms of sympathetic nervous system activity, as assessed in selected autonomic ganglia and their innervating territories in rats by measuring tyrosine hydroxylase activity, have been previously reported [22]. In our previous study, we addressed the question of whether the administration of melatonin, known to augment the amplitude of circadian rhythms in several experimental situations, could restore age-related impairment of circadian autonomic activity in cervical, stellate, celiac-mesenteric and hypogastric sympathetic ganglia, and in the adrenal medulla and heart of rats.…”

Section: Discussionmentioning

confidence: 81%

“…Treatment of rats with melatonin was highly effective, in old rats, in restoring the amplitude of daily rhythmicity of every autonomic parameter tested. The effect was equally effective with 10-or 100-Ìg doses of melatonin in old rats, while only the highest dose increased NE synthesis in young rats [22].…”

Section: Discussionmentioning

confidence: 87%

“…Thus, the first objective of the present study was to examine, at 6 time points throughout a 24-hour cycle, pineal norepinephrine (NE) content and serotonin (5-HT) turnover [estimated from the ratio of 5-hydroxyindoleacetic acid (5-HIAA) to 5-HT] in young (2 months) and aged (18-20 months) rats. In addition, and since we previously reported that the administration of melatonin to aged rats effectively restored the amplitude of 24-hour rhythms of NE and acetylcholine synthesis in cervical, stellate, celiacmesenteric and hypogastric ganglia, and in the adrenal medulla and heart of rats [22], the ability of melatonin treatment to revert the age-induced changes in the 24-hour rhythm of pineal NE content and 5-HT turnover was assessed.…”

Section: Introductionmentioning

confidence: 99%

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Age-Related Changes in 24-Hour Rhythms of Norepinephrine Content and Serotonin Turnover in Rat Pineal Gland: Effect of Melatonin Treatment

Pazo¹,

Cardinali

Cano³

et al. 2002

Neurosignals

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The 24-hour rhythms of pineal norepinephrine (NE) content and serotonin (5-HT) turnover [estimated from the ratio of 5-hydroxyindoleacetic acid (5-HIAA) to 5-HT] were studied in young (2 months) and aged (18–20 months) Wistar rats killed at 6 different time points throughout a 24-hour cycle. In the first study, significant changes dependent on the time of day were identified, with acrophases in the first half of the activity span for both parameters. Old rats showed significantly smaller mesor and amplitude of the 24-hour rhythm of pineal NE content. They also showed decreased amplitude of the pineal 5-HT turnover rhythm, in the absence of changes in mesor. In old rats, pineal 5-HT and 5-HIAA concentrations were 41–47% of those found in young rats. In a second study, young and old rats received daily intraperitoneal injections of melatonin (30 µg) or vehicle for 11 days at 19.00 h (i.e. 11 h after light on). Analyzed as a main factor in a factorial analysis of variance, both pineal NE content and 5-HT turnover decreased in old rats while pineal 5-HT turnover increased after melatonin treatment. Melatonin treatment augmented the amplitude of the 24-hour rhythm of pineal NE content by 120 and 52% in young and old rats, respectively. The amplitude of the 24-hour rhythm of pineal 5-HT turnover almost doubled after melatonin treatment in young rats and did not change in old rats. Melatonin injection did not modify the rhythm’s acrophase. The results indicate that old rats had lower amplitude and lower mesor values of 24-hour variations in pineal NE content and 5-HT turnover. Melatonin treatment only partly restored pineal NE content and was devoid of activity on pineal 5-HT turnover and 5-HT and 5-HIAA concentration in old rats. Impairment of pineal melatonin synthesizing capacity and intrapineal responses to melatonin may underlie pineal aging in rats.

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Section: Discussionmentioning

confidence: 66%

Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

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Age-Related Changes in 24-Hour Rhythms of Norepinephrine Content and Serotonin Turnover in Rat Pineal Gland: Effect of Melatonin Treatment

Pazo¹,

Cardinali

Cano³

et al. 2002

Neurosignals

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“…Melatonin is also a potent antioxidant, acting by itself rather than through specific binding sites [91,92]. In addition, melatonin could affect centrally hypothalamic hormone release [93] as well as the activity of autonomic pathways to the lymphoid organs [94]. Whether the melatonin rhythm is an important physiological efferent pathway for the suprachiasmatic nuclei to export synchronicity to the immune system awaits experiments employing physiological rather than pharmacological conditions (i.e.…”

Section: Melatonin Is An Immunoregulatory Signalmentioning

confidence: 99%

Psychoimmune Neuroendocrine Integrative Mechanisms Revisited

Cardinali¹,

Cutrera²,

Esquifino³

2000

Neurosignals

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This review analyzes recent publications on the topic of psycho-immune-neuroendocrine integrative mechanisms. Results on the role of cytokines in cognitive processes and in a major neuroendocrine event, i.e. the release of gonadotropin-releasing hormone, are discussed, as are the effects of cytokines on central neurotransmission. The control of immune responses by local sympathetic nerves, a major pathway in neuroimmune communication, is discussed. This review also updates information indicating that melatonin is a circulating signal affecting the periodic organization of the immune response.

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Melatonin Receptors in Central Nervous System

Dubocovich

2007

Handbook of Contemporary Neuropharmacology

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The functional role of melatonin receptors in the mammalian central nervous system and their therapeutic potential is discussed. Melatonin, dubbed the “hormone of darkness,” is produced primarily in the pineal gland and retina following circadian rhythms with high levels of night. The chapter describes the structure, molecular pharmacology, signaling, and function of the MT1 and MT2 mammalian melatonin receptors. This is followed by discussion of recent advances in the regulation of melatonin receptor sensitivity and its role in circadian rhythm modulation by the circadian timing system. Recent advances in the discovery and development of therapeutic agents targeting melatonin receptors for the treatment of insomnia, circadian rhythm dysfunctions, and depression are also highlighted.

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Diurnal rhythms in norepinephrine and acetylcholine synthesis of sympathetic ganglia, heart and adrenals of aging rats: Effect of melatonin

Cited by 31 publications

References 37 publications

Age-Related Changes in 24-Hour Rhythms of Norepinephrine Content and Serotonin Turnover in Rat Pineal Gland: Effect of Melatonin Treatment

Age-Related Changes in 24-Hour Rhythms of Norepinephrine Content and Serotonin Turnover in Rat Pineal Gland: Effect of Melatonin Treatment

Psychoimmune Neuroendocrine Integrative Mechanisms Revisited

Melatonin Receptors in Central Nervous System

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