Article

Blockade of endogenous growth hormone-releasing hormone receptors dissociates nocturnal growth hormone secretion and slow-wave sleep

Department of Internal Medicine, Division of Endocrinology and Metabolism, University of Michigan Medical Center, Ann Arbor, Michigan, USA.
European Journal of Endocrinology (Impact Factor: 3.69). 11/2004; 151(5):561-6. DOI: 10.1530/eje.0.1510561
Source: PubMed

ABSTRACT A temporal association between non-rapid eye movement (NREM) sleep stages 3 and 4 and nocturnal augmentation of GH release was found long ago, yet the precise mechanism for this association has not been identified. It has been shown, however that pulsatile GHRH administration increases both slow-wave sleep (SWS) and GH. Based on these data, a role for GHRH as an inducer of SWS was proposed. To test this hypothesis, we have performed the corollary experiment whereby the action of endogenous GHRH has been antagonized.
Healthy men (20-33 years old) had an infusion of GHRH antagonist ((N-Ac-Tyr(1), D-Arg(2)) GHRH-29 (NH(2))) or saline for a 12-h period, between 2100 and 0900 h. An i.v. bolus of GHRH was given at 0700 h and GH samples were drawn from 0700 to 0900 h to document the efficacy of GH suppression by the GHRH antagonist.
A limited montage sleep study was recorded from 2300 to 0700 h during each admission. Plasma GH concentrations were analyzed by the use of a sensitive chemiluminometric assay.
Effectiveness of the GHRH antagonist was validated in all subjects by demonstrating 93+/-1.8% (P=0.012) suppression of GH response to a GHRH bolus. Polysomnography demonstrated that the percentage of SWS was not different when saline and GHRH antagonist nights were compared (P=0.607); other quantifiable sleep parameters were also unchanged.
We conclude that endogenous GHRH is indispensable for the nocturnal augmentation of GH secretion, but that it is unlikely to participate in the genesis of SWS.

0 Followers
 · 
49 Views
 · 
0 Downloads
  • Source
    • "16(3):jul/set. 2006 Chase, 2001; Jessup et al., 2004; Mazza et al., 2004 "
    [Show abstract] [Hide abstract]
    ABSTRACT: The Bach Flowers Remedies (BFR's) are worldwide used as an alternative therapeutical approach for several pathologies, being considered by WHO as natural therapy since 1956. Despite the unknown mechanism of action, the BFR's have been widely used on treatment of several neuropsychiatry diseases. Based on pharmacological models used to detect ansiolitic, antidepressant, hypnotic and neuroleptyc effects of different substances, the aim of this work was to evaluate possible central effects of the BFR's. For this purpose, albino mice received BFR's treatment (0.45 mL) by oral route 1 hour prior to each test. The results revealed that the Gorse flower alone and a mix of White chestnut, Agrymony and Vervain showed antidepressant and hypnotic effects, respectively. On the anxiety model, Agrymony showed an ansiolitic effect but no neuroleptyc effects were observed for Clematis floral therapy. The herein described results allow us to conclude that the studied BFR's central effects may be partially detected through pharmacological models currently and widely used on psychotropic agents research.
    Revista Brasileira de Farmacognosia 09/2006; 16(3):365-371. · 0.80 Impact Factor
  • Source
    • "16(3):jul/set. 2006 Chase, 2001; Jessup et al., 2004; Mazza et al., 2004 "
    [Show abstract] [Hide abstract]
    ABSTRACT: RESUMO: Os Remédios Florais de Bach (RFB), constituem um método alternativo de tratamento usado largamente na terapêutica de várias patologias em muitos países do mundo. Os RFB são reconhecidos como tratamento natural pela OMS desde 1956. Embora o mecanismo de ação dos RFB ainda não tenha sido elucidado, eles vêm sendo indicados para o tratamento de várias doenças neuropsiquiátricas. O objetivo do presente trabalho foi detectar possíveis efeitos centrais dos RFB em modelos farmacológicos utilizados na pesquisa de substâncias com efeitos ansiolíticos, hipnóticos, antidepressivos e neurolépticos. Para tanto, camundongos receberam um tratamento agudo via oral (0,45 mL) 1 hora antes dos testes. Os resultados mostraram que os fl orais Gorse e, em conjunto, White chestnut, Agrymony e Vervain exibiram perfi s antidepressivo e hipnótico, respectivamente. No modelo de ansiedade foi detectado efeito ansiolítico do fl oral Agrymony. Entretanto, não foram observados efeitos neurolépticos do fl oral Clematis. Os resultados nos levam a sugerir que os efeitos centrais dos fl orais avaliados podem ser parcialmente detectados através de modelos farmacológicos utilizados na pesquisa de agentes psicotrópicos. Unitermos: Remédios Florais de Bach (RFB), modelos farmacológicos, depressão, ansiedade, esquizofrenia, insônia. ABSTRACT: "Evaluation of central effects of Bach Flowers Remedies in mice using specifi c pharmacological models". The Bach Flowers Remedies (BFR's) are worldwide used as an alternative therapeutical approach for several pathologies, being considered by WHO as natural therapy since 1956. Despite the unknown mechanism of action, the BFR's have been widely used on treatment of several neuropsychiatry diseases. Based on pharmacological models used to detect ansiolitic, antidepressant, hypnotic and neuroleptyc effects of different substances, the aim of this work was to evaluate possible central effects of the BFR's. For this purpose, albino mice received BFR's treatment (0.45 mL) by oral route 1 hour prior to each test. The results revealed that the Gorse fl ower alone and a mix of White chestnut, Agrymony and Vervain showed antidepressant and hypnotic effects, respectively. On the anxiety model, Agrymony showed an ansiolitic effect but no neuroleptyc effects were observed for Clematis fl oral therapy. The herein described results allow us to conclude that the studied BFR's central effects may be partially detected through pharmacological models currently and widely used on psychotropic agents research.
    Revista Brasileira de Farmacognosia 01/2006; 16(3). DOI:10.1590/S0102-695X2006000300014 · 0.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The function of sleep is one of the most persistent and perplexing mysteries in biology. Many theories have been proposed to explain why we sleep, but most account for only a portion of sleep behavior and very few enjoy strong experimental support. A critical review of current findings leads to the following conclusions. Sleep is for the brain rather than the body, and the neural process most impacted by sleep is cognition. Sleep may influence cognition in many ways, including the removal of a toxic byproduct of wakefulness, or the restoration of neural substrates needed for mental processes. The evidence for these possibilities, however, is weak or equivocal. On the other hand, converging lines of evidence support the hypothesis that sleep promotes brain plasticity.
    Reviews in the neurosciences 02/2006; 17(4):375-92. DOI:10.1515/revneuro.2006.17.4.375 · 3.31 Impact Factor
Show more

Preview

Download
0 Downloads
Available from