Norepinephrine metabolism in the rat brain following acute and chronic administration of thyrotropin releasing hormone

Reigle, Thomas G.; Avni, Jacob; Platz, P.; Schildkraut, Joseph J.; Plotnikoff, Nicholas P.

doi:10.1007/bf00426676

Cited by 45 publications

(3 citation statements)

References 10 publications

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“…Large numbers of experiments suggest that TRH has modulatory effects on these neurotransmitters. TRH is reported to enhance central noradrenaline turnover, and this effect may mediate the antidepressant effect of TRH (Keller et al, 1974;Reigle et al, 1974). It has also been reported that TRH analogs increase dopamine release in brain slices (Sharp et al, 1982), and in vivo experiments suggest that dopaminergic systems are involved in the stimulating effects of TRH on locomotor activity (Yamamura et al, 1991).…”

Section: Discussionmentioning

confidence: 96%

Effects of Thyrotropin-Releasing Hormone and Its Analogs on Daytime Sleepiness and Cataplexy in Canine Narcolepsy

et al. 1997

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The therapeutic potential of thyrotropin-releasing hormone (TRH) and TRH analogs in narcolepsy, a sleep disorder characterized by abnormal rapid eye movement (REM) sleep and daytime sleepiness, was examined using the canine model. The effects of TRH and the biologically stable TRH analogs CG3703, CG3509, and TA0910 on daytime sleep and cataplexy, a symptom of abnormal REM sleep, were assessed using polysomnographic recordings and the food elicited cataplexy test (FECT), respectively. CG3703 (100 and 400 g/kg, i.v.) and TA0910 (100 and 400 g/kg, i.v.) significantly increased wakefulness and decreased sleep in narcoleptic canines, whereas TRH (400 and 1600 g/kg, i.v.) had no significant effect. TRH (25-1600 g/kg, i.v.) and all three TRH analogs, CG3703 (6.25-400 g/kg, i.v., and 0.25-16 mg/kg, p.o.), CG3509 (25-1600 g/kg, i.v.), and TA0910 (25-1600 g/kg, i.v.), significantly reduced cataplexy in canine narcolepsy. These compounds did not produce any significant side effects during behavioral assays, nor did they alter free T 3 and T 4 levels in serum even when used at doses that completely suppressed cataplexy. Although more work is needed to establish the mode of action of TRH analogs on alertness and REM sleep-related symptoms, our results suggest a possible therapeutic application for TRH analogs in human sleep disorders.

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Section: Discussionmentioning

confidence: 96%

Effects of Thyrotropin-Releasing Hormone and Its Analogs on Daytime Sleepiness and Cataplexy in Canine Narcolepsy

et al. 1997

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“…We have also found that after synthesis inhibition, norepinephrine levels are more quickly reduced in TRH-treated mice (3), indicating increased turnover. On the other hand, Reigle et al (19) could find no clear effect of TRH on brain disposition or metabolism of norepinephrine. The present study has not furnished an answer to the question of the mechanism of the central action of TRH.…”

Section: Discussionmentioning

confidence: 97%

Parameters of Alteration of Pentobarbital Response by Hypothalamic Polypeptides

Prange¹,

Breese²,

Jahnke³

et al. 1975

Neuropsychobiology

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Both thyrotropin-reieasing hormone (TRH) and amphetamine antagonize pentobarbital. They are more effective in the day than at night. This is true for TRH even when the dose of pentobarbital is increased at night to prolong sedation. Under this condition the day-night difference is lost for amphetamine. Both substances are more effective in cold ambient temperatures (18 °C) and less effective in warm temperatures, but their activity at warmer temperatures (37 °C) is still substantial. In contrast, somatotropin release-inhibiting factor (SRIF) augments the effects of pentobarbital at room temperature. This action is unaffected by time of day. However, the increase in sleeping time is lost in both a warm environment and in a cold environment.

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“…It may be pointed out that, unlike tricyclic antidepressants, TRH failed to inhibit the neuronal uptake of 3H-NE [Reigle et al, 1974]. It is therefore possible that TRH eleicits its ameliorative effects during depression by increasing the synthesis and release of monoamines, in turn making more of these available in the vicinity of receptor sites.…”

Section: Discussionmentioning

confidence: 99%

Enhancement of Locomotor Activity and Catecholamine and 5-Hydroxytryptamine Metabolism by Thyrotropin Releasing Hormone

Agarwal¹,

Rastogi²,

Singhal³

1977

Neuroendocrinology

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I.p. administration of thyrotropin releasing hormone (TRH) twice daily for 10 days produced a dose- and time-dependent rise in spontaneous locomotor activity of young rats. A significant increase in the levels of cerebrocortical 5-hydroxytryptamine (5-HT) and dopamine (DA) also observed in animals treated with varying amounts of TRH (2, 4 and 8 mg/kg/day). The concentration of these amines was elevated after a 10 or 15 day treatment with a 4 mg/kg daily dose of TRH, but no change was observed in rats given the hormone for only 5 days. The amount of 5-hydroxyindoleacetic acid (5-HIAA) rose after a 15 day treatment; however, no significant change was seen in norepinephrine (NE) levels of any of the groups examined. The activity of brain stem tyrosine hydroxylase (TH) showed a dose-dependent increase in rats chronically treated with TRH. Although there was a significant rise in brain stem tryptophan hydroxylase (TPH) activity as well, the response was neither time- nor dose-dependent. A single injection of 200 µCi of ¹³¹I at birth induced hypothyroidism, which was accompanied by decreased brain stem TH activity. However, 5-HIAA levels were markedly enhanced in hypothyroid rats. These changes were partially reversed after a 10 day treatment with 4 mg/kg daily dose of TRH. Our data demonstrate that the rise in spontaneous locomotor activity following TRH administration in normal rats is related to altered catecholamine and possibly 5-HT metabolism brought about by this hormone. Furthermore, since TRH treatment produced similar changes in the noradrenergic system of normal and hypothyroid rats, but not in the dopaminergic or 5-hydroxytryptaminergic systems, it is suggested that part of the central effects of TRH are independent of the pituitary-thyroid axis.

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Norepinephrine metabolism in the rat brain following acute and chronic administration of thyrotropin releasing hormone

Cited by 45 publications

References 10 publications

Effects of Thyrotropin-Releasing Hormone and Its Analogs on Daytime Sleepiness and Cataplexy in Canine Narcolepsy

Effects of Thyrotropin-Releasing Hormone and Its Analogs on Daytime Sleepiness and Cataplexy in Canine Narcolepsy

Parameters of Alteration of Pentobarbital Response by Hypothalamic Polypeptides

Enhancement of Locomotor Activity and Catecholamine and 5-Hydroxytryptamine Metabolism by Thyrotropin Releasing Hormone

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