Chronic atropine administration diminishes the contribution of vasoactive intestinal polypeptide to heart rate regulation
Language English Country Czech Republic Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
18052688
DOI
10.33549/physiolres.931350
PII: 1350
Knihovny.cz E-resources
- MeSH
- Adrenergic alpha-Antagonists pharmacology MeSH
- Hormone Antagonists pharmacology MeSH
- Muscarinic Antagonists administration & dosage MeSH
- Atropine administration & dosage MeSH
- Adrenergic beta-Antagonists pharmacology MeSH
- Time Factors MeSH
- Electric Stimulation MeSH
- Phentolamine pharmacology MeSH
- Rats MeSH
- Metipranolol pharmacology MeSH
- Vagus Nerve drug effects metabolism MeSH
- Rats, Wistar MeSH
- Receptors, Muscarinic drug effects metabolism MeSH
- Heart Rate drug effects MeSH
- Heart Atria innervation metabolism MeSH
- Vasoactive Intestinal Peptide antagonists & inhibitors metabolism pharmacology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Adrenergic alpha-Antagonists MeSH
- Hormone Antagonists MeSH
- Muscarinic Antagonists MeSH
- Atropine MeSH
- Adrenergic beta-Antagonists MeSH
- Phentolamine MeSH
- Metipranolol MeSH
- Receptors, Muscarinic MeSH
- vasoactive intestinal peptide, 4-chloro-Phe(6)-Leu(17)- MeSH Browser
- Vasoactive Intestinal Peptide MeSH
Vasoactive intestinal polypeptide (VIP) is implicated in the modulation of vagal effects on the heart rate. In this study, the impact of acute and chronic atropine administration on VIP levels in rat heart atria was investigated in relation to heart rate in the course of vagus nerves stimulation. Anaesthetised control and atropinised (10 mg/kg/day for 10 days) rats pretreated with metipranolol and phentolamine that were either given or not a single dose of atropine were subjected to bilateral vagus nerve stimulation (30 min: 0.7 mA, 20 Hz, 0.2 ms). VIP concentrations in the atria were determined after each stimulation protocol. In control rats with or without single atropine administration, the heart rate upon vagal stimulation was higher than in atropinised animals with or without single atropine dose, respectively. VIP concentrations in the control atria were significantly decreased after the stimulation; the decrease was comparable both in the absence and presence of a single dose of atropine. Compared to controls, VIP levels were significantly decreased after chronic atropine treatment and they were not further reduced by vagal stimulation and single atropine administration. Administration of VIP antagonist completely abolished the differences in the heart rate upon vagal stimulation between control and atropinised groups. In conclusion, the data indicate that chronic atropine administration affects VIP synthesis in rat heart atria and consequently it modifies the heart rate regulation.
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