Relative sensitivity of the canine sines node and atrioventricular node to acetylcholine
| Autor: | G. E. Musgrave, S. D. Beckett, C. E. Branch |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Male
Physiology Dogs Heart Conduction System Heart Rate Physiology (medical) Animals Medicine Anesthesia Sinus (anatomy) Sinoatrial Node Pharmacology Dose-Response Relationship Drug business.industry Node (networking) General Medicine Anatomy Atrioventricular node Acetylcholine medicine.anatomical_structure Atrioventricular Node Female business Sensitivity (electronics) medicine.drug |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 59:1058-1062 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y81-161 |
| Popis: | This study was undertaken to evaluate the relative sensitivity of the canine sinus and atrioventricular (AV) nodes to acetylcholine (Ach). A dose-dependent increase in both A–A and R–R intervals occurred when Ach (5–320 μg/kg) was injected into the left ventricle of both conscious and anesthetized dogs. Comparison of the ED50 values for Ach (derived by weighted nonlinear least squares regression analysis of the dose-dependent changes in the A–A and R–R intervals) revealed the AV node to be 1.9-fold more sensitive to the effect of Ach than the sinus node in the conscious dogs and 3.3-fold more sensitive than the sinus node in the anesthetized group. The results imply that the greater sensitivity of the AV node to Ach is, at least in part, responsible for the occasional second degree block commonly observed in clinically normal dogs. |
| Databáze: | OpenAIRE |
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