Regulatory mechanism of body temperature in the central nervous system during the maintenance phase of hibernation in Syrian hamsters: Involvement of β-endorphin
| Autor: | Yutaka Tamura, Hirofumi Inoue, Mayuko Monden, Mitsuteru Shintani, Hirohito Shiomi |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Central Nervous System
Hibernation endocrine system medicine.medical_specialty Lateral hypothalamus medicine.drug_class Hypothalamus Receptors Opioid mu Cell Count Hypothermia Biology Polymerase Chain Reaction chemistry.chemical_compound Proopiomelanocortin Opioid receptor Cricetinae Internal medicine medicine Animals Molecular Biology Injections Intraventricular Brain Chemistry Mesocricetus General Neuroscience beta-Endorphin Enkephalin Ala(2)-MePhe(4)-Gly(5) Receptor antagonist Immunohistochemistry Analgesics Opioid Preoptic area DAMGO Endocrinology Proprotein Convertase 1 chemistry biology.protein Neurology (clinical) Oligopeptides Proto-Oncogene Proteins c-fos hormones hormone substitutes and hormone antagonists Body Temperature Regulation Developmental Biology |
| Zdroj: | Brain Research. 1448:63-70 |
| ISSN: | 0006-8993 |
| Popis: | We have shown previously that intracerebroventricular (icv) injection of naloxone (a non-selective opioid receptor antagonist) or naloxonazine (a selective μ1-opioid receptor antagonist) at the maintenance phase of hibernation arouses Syrian hamsters from hibernation. This study was designed to clarify the role of β-endorphin (an endogenous μ-opioid receptor ligand) on regulation of body temperature (T b ) during the maintenance phase of hibernation. The number of c-Fos-positive cells and β-endorphin-like immunoreactivity increased in the arcuate nucleus (ARC) after hibernation onset. In contrast, endomorphin-1 (an endogenous μ-opioid receptor ligand)-like immunoreactivity observed on the anterior hypothalamus decreased after hibernation onset. In addition, hibernation was interrupted by icv injection of anti-β-endorphin antiserum at the maintenance phase of hibernation. The mRNA expression level of proopiomelanocortin (a precursor of β-endorphin) on ARC did not change throughout the hibernation phase. However, the mRNA expression level of prohormone convertase-1 increased after hibernation onset. [D-Ala 2 ,N-MePhe 4 ,Gly-ol 5 ] enkephalin (DAMGO, a selective μ-opioid receptor agonist) microinjection into the dorsomedial hypothalamus (DMH) elicited the most marked T b decrease than other sites such as the preoptic area (PO), anterior hypothalamus (AH), lateral hypothalamus (LH), ventromedial hypothalamus and posterior hypothalamus (PH). However, microinjected DAMGO into the medial septum indicated negligible changes in T b . These results suggest that β-endorphin which synthesizes in ARC neurons regulates T b during the maintenance phase of hibernation by activating μ-opioid receptors in PO, AH, VMH, DMH and PH. |
| Databáze: | OpenAIRE |
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