These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Melatonin restores endothelium-dependent relaxation in aortic rings of pancreatectomized rats.
    Author: Reyes-Toso CF, Linares LM, Ricci CR, Obaya-Naredo D, Pinto JE, Rodríguez RR, Cardinali DP.
    Journal: J Pineal Res; 2005 Nov; 39(4):386-91. PubMed ID: 16207294.
    Abstract:
    In rats turned hyperglycemic by a subtotal pancreatectomy, a decreased relaxation response of aortic rings to acetylcholine (ACh) was found; this effect was amplified by preincubation in a high glucose medium (44 mmol/L). The relaxation response to ACh did not occur in endothelium-denuded rings or after the aortic rings were exposed to l-nitro-arginine methyl ester [L-NAME, a nitric oxide (NO) synthase inhibitor]. Incubation with the NO donor sodium nitroprusside (SNP) restored the impaired relaxation response seen in endothelium-denuded or L-NAME-treated aortic rings. Pancreatectomy decreased the vasorelaxation of aortic rings caused by SNP. Only in pancreatectomized rats, incubation in a high glucose medium impaired the relaxation effect of SNP. To assess whether melatonin preincubation reversed the impaired relaxation response to ACh (intact endothelium aortic rings) or to SNP (endothelium-denuded or L-NAME-treated rings) in hyperglycemic rats, cumulative dose-response curves were performed in the presence of 10(-5) mol/L melatonin. Melatonin preincubation did not modify ACh-induced relaxation of aortic rings in a normal glucose concentration but was highly effective in preventing the impairment of relaxation caused by a high glucose solution. Melatonin was also effective in restoring the impaired SNP-induced vasorelaxation seen in endothelium-denuded or L-NAME-treated aortic rings from hyperglycemic rats. The results further support the improvement by melatonin of the endothelial-mediated relaxation in blood vessels of diabetic rats.
    [Abstract] [Full Text] [Related] [New Search]