Effects of acute hypoglycemia on the orexin system in rat / 中国医学科学杂志(英文版)
Chinese Medical Sciences Journal
; (4): 55-58, 2005.
Article
in En
| WPRIM
| ID: wpr-305459
Responsible library:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells.</p><p><b>METHODS</b>Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.</p><p><b>CONCLUSIONS</b>Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.</p>
Full text:
1
Index:
WPRIM
Main subject:
Pharmacology
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Protein Precursors
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Blood Glucose
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Neuropeptides
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RNA, Messenger
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Random Allocation
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Islets of Langerhans
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Rats, Wistar
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Receptors, Neuropeptide
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Receptors, G-Protein-Coupled
Limits:
Animals
Language:
En
Journal:
Chinese Medical Sciences Journal
Year:
2005
Type:
Article