Related Experiment Videos
Quantitative and sustained suppression of renal sympathetic nerve activity by left atrial distension in conscious
K Miki1, Y Hayashida, K Shiraki
1Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Kitakyushu, Japan.
Abstract:
In order to investigate the interrelations between left atrial pressure (Pla) and renal sympathetic nerve activity (RSNA) and heart rate (HR), Pla was increased by a balloon both in conscious sham-operated and cardiac-denervated dogs. RSNA was decreased and HR was increased with increasign Pla in sham-operated dogs. The reflex changes in RSNA and HR induced by the stimulation of atrial receptors persisted for at least 15 min. There was a consistent relationship between Pla and RSNA which could be described by a single exponential equation: % delta RSNA = -80.0(1-e-0.395 delta Pla), or by a linear equation when delta Pla was less than 6 mmHg; % delta RSNA = -13.5 delta Pla-2.25. The relationship between Pla and HR can be described by a single exponential equation: delta HR = 86.5(1-e-0.125 delta Pla). A significant linear relationship between RSNA and HR was obtained during a graded left atrial distention (% delta RSNA = -1.08 delta HR-17.7). In cardiac-denervated dogs, RSNA tended to increase and HR remained constant during the left atrial distention. These results indicate that left atrial receptors regulate RSNA and HR in both a quantitative and sustained manner in conscious sham-operated dogs.