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Peripheral 5-HT1A and 5-HT7 Serotonergic Receptors Modulate Parasympathetic Neurotransmission in Long-Term Diabetic Rats.
- Source :
- Experimental Diabetes Research; 2010, p1-10, 10p, 1 Chart, 8 Graphs
- Publication Year :
- 2010
-
Abstract
- We analyzed the modulation of serotonin on the bradycardia induced in vivo by vagal electrical stimulation in alloxan-induced long-term diabetic rats. Bolus intravenous administration of serotonin had a dual effect on the bradycardia induced either by vagal stimulation or exogenous Ach, increasing it at low doses and decreasing it at high doses of 5-hydroxytryptamine (5-HT), effect reproduced by 5-carboxamidotryptamine maleate (5-CT), a 5-HT<subscript>1/7</subscript> agonist. The enhancement of the bradycardia at low doses of 5-CT was reproduced by 5-HT<subscript>1A</subscript> agonist 8-hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT) and abolished by WAY-100,635, 5-HT<subscript>1A</subscript> antagonist. Pretreatment with 5-HT<subscript>1</subscript> antagonist methiothepin blocked the stimulatory and inhibitory effect of 5-CT, whereas pimozide, 5-HT<subscript>7</subscript> antagonist, only abolished 5-CT inhibitory action. In conclusion, long-term diabetes elicits changes in the subtype of the 5-HT receptor involved in modulation of vagally induced bradycardia. Activation of the 5- HT<subscript>1A</subscript> receptors induces enhancement, whereas attenuation is due to 5-HT<subscript>7</subscript> receptor activation. This 5-HT dual effect occurs at pre- and postjunctional levels. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 16875214
- Database :
- Complementary Index
- Journal :
- Experimental Diabetes Research
- Publication Type :
- Academic Journal
- Accession number :
- 97128064
- Full Text :
- https://doi.org/10.1155/2010/686734