Mechanisms of Melatonin Inhibition of Neurohypophysial Hormone Release From the Rat Hypothalamus In Vitro

Yasin, Sharifah A.; Forsling, Mary L.

doi:10.1016/s0361-9230(97)00289-x

Cited by 20 publications

(6 citation statements)

References 29 publications

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“…Although the action of melatonin is mostly inhibitory, excitation of Purkinje cells in the pigeon cerebellum [Semm and Vollrath, 1984], enhancement of GABA A -mediated current in rat SCN [Wan et al, 1999], chick spinal cord neurons [Wu et al, 1999], and activation of rat striatal neurons [Leon et al, 1998] have also been reported. These diverse actions of melatonin also correlate with biochemical data which show the influence of melatonin on the release/uptake of neurotransmitters [Dubocovich, 1983;Faillace et al, 1996] and hormones [Watanabe et al, 1998;Yasin and Forsling 1998].…”

Section: Introductionsupporting

confidence: 61%

The modulation of neuronal activity by melatonin: In vitro studies on mouse hippocampal slices

Hogan

El-Sherif

Wieraszko

2001

Journal of Pineal Research

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The influence of melatonin on evoked potentials recorded from the CAI field of mouse hippocampal slices was investigated. Melatonin (0.1-2.0 mM) and its analog, 6-chloromelatonin (0.1-0.5 mM) depressed evoked potentials (EPSP and the population spike) in a concentration-dependent manner. The melatonin-induced depression was followed by a slow recovery phase. Since the fiber potential was not affected, it was concluded that melatonin influenced synaptic efficiency and/or cell excitability. Luzindole, an antagonist of MT2 melatonin receptors, although slightly depressing evoked potentials when applied by itself (100 microM), blocked any further inhibition by melatonin when added afterwards. We concluded that melatonin reduced synaptic efficiency and/or excitability of hippocampal neurons most likely through interaction with MT2 melatonin receptors, but other possible mechanisms of melatonin action are also considered.

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Section: Introductionsupporting

confidence: 61%

The modulation of neuronal activity by melatonin: In vitro studies on mouse hippocampal slices

Hogan

El-Sherif

Wieraszko

2001

Journal of Pineal Research

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“…If the factor involved in mediating the effects of the pineal gland on hormone release is melatonin, then an indirect action is likely since vasopressin and oxytocin neurones do not possess melatonin receptors (26). The possibility of an indirect effect is also consistent with the observations that the modulatory effect of melatonin on vasopressin release from the hypothalamus in vivo is altered by concomitant block of acetylcholinergic transmission (27) thought to be a major pathway in the transduction of osmotic information to the magnocellular neurones. Whether melatonin acts directly on the OVLT is unclear as melatonin receptors have not been reported in this circumventricular area.…”

Section: Discussionsupporting

confidence: 82%

The Effect of Pinealectomy on Osmotically Stimulated Vasopressin and Oxytocin Release and Fos Protein Production within the Hypothalamus of the Rat

Windle¹,

Luckman

Stoughton

et al. 1996

J Neuroendocrinology

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Osmotically stimulated vasopressin and oxytocin release were measured in pinealectomized and sham operated male rats infused with hypertonic sodium chloride. Neuronal activation in the hypothalamic regions associated with oxytocin and vasopressin release was investigated by quantitative assessment of Fos protein production. The osmotically stimulated release of both vasopressin and oxytocin was significantly lower in pinealectomized animals as compared to sham operated controls. The slope of regression lines between plasma osmolality and hormone concentrations in the sham animals showed a 1.0 +/- 0.1 pmol per mosm/kg rise in vasopressin and 2.0 +/- 0.4 pmol per mosm/kg rise in oxytocin whilst in the pinealectomized animals these values were significantly lower at 0.4 +/- 0.1 pmol vasopressin per mosm/kg and 0.8 +/- 0.2pmol oxytocin per mosm/kg. The osmotic thresholds for hormone release were unaffected by pinealectomy. Fos production was also significantly lower in the supraoptic nucleus and organ vasculosum of the lamina terminalis in the pinealectomized rat at 62 +/- 20 and 59 +/- 9 Fos immunoreactive cells/section as compared to corresponding values of 202 +/- 31 and 123 +/- 20 Fos immunoreactive cells/section in the shams. These observations suggest that reduced hormone release in the pinealectomized animal is due to lowered responsiveness of central osmoregulatory mechanisms and that melatonin may therefore influence the activation of the magnocellular system.

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“…In addition to effects on neurotransmitter release, recent studies support earlier observations that prostaglandins influence secretion of various hypothalamic, pituitary and pineal hormones [72][73][74][75][76][77]. It appears that COX products are involved differently in regulation of different hormones, but COX isoforms and cell types involved in the modulation of hypothalamic function have not been fully elucidated.…”

Section: Physiological Effects In Other Neuronal Systemsmentioning

confidence: 52%

Cyclooxygenases in the Central Nervous System: Implications for Treatment of Neurological Disorders

Yermakova¹,

O’Banion²

2000

CPD

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Recognition of two isoforms of cyclooxygenase and reports that nonsteroidal anti-inflammatory drugs may be beneficial in devastating neurological conditions such as Alzheimer's disease have led to increased interest in cyclooxygenase function in the nervous system. In the present paper we review current data on the multiplicity of cyclooxygenase and prostaglandin mediated effects in the central nervous system (CNS). We discuss CNS cells types, including neurons, glia, and cerebrovascular elements, where cyclooxygenases-1 and -2 are expressed under normal conditions or can be induced by physiological or pathological stimuli. We also address physiological processes such as pain sensitization, CNS inflammation and fever induction that are regulated or modified by cyclooxygenase activity. Finally, we describe potential roles of cyclooxygenase in neurological diseases and rationales for nonsteroidal anti-inflammatory drug use in the treatment of neurodegenerative disorders, stroke and CNS injury.

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Mechanisms of Melatonin Inhibition of Neurohypophysial Hormone Release From the Rat Hypothalamus In Vitro

Cited by 20 publications

References 29 publications

The modulation of neuronal activity by melatonin: In vitro studies on mouse hippocampal slices

The modulation of neuronal activity by melatonin: In vitro studies on mouse hippocampal slices

The Effect of Pinealectomy on Osmotically Stimulated Vasopressin and Oxytocin Release and Fos Protein Production within the Hypothalamus of the Rat

Cyclooxygenases in the Central Nervous System: Implications for Treatment of Neurological Disorders

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