title: Acute inhibition of renin release during left circumflex coronary occlusion in dogs.
abstract: We examined the reflex effect of brief left circumflex coronary artery occlusion (CAO) on renal blood flow (RBF) and renin secretion (RS). Studies were conducted in alpha-chloralose-anesthetized dogs maintained on a salt-free diet for at least 3 days. A snare was placed around the left circumflex artery near its origin. The left renal artery and vein were exposed via flank incision, a flow probe was placed around the artery, and a curved needle was inserted into the vein for collection of renal venous blood. Values of blood pressure (BP), RBF, and RS were obtained for a 30-min control period, 4 min after the completion of a 10-ml/kg hemorrhage, 1 and 5 min after CAO, and 15 min after reinfusion. The CAO consisted of two 1-min occlusions separated by a 1-min interval. The results indicate that CAO reflexively inhibits the RS response to nonhypotensive hemorrhage and prevents renal vasoconstriction (P less than 0.05, n = 7). Both effects were completely abolished after vagotomy (n = 5). Renal denervation also abolished the response (n = 5). No response was observed during identical time controls (n = 5). The response was more pronounced in dogs with carotid sinus denervation, even though CAO resulted in marked reductions in BP (20%) under these conditions. These results demonstrate the presence of a cardiorenal reflex that can be activated by myocardial hypoxia and that acutely suppresses RS. This response is more pronounced in the absence of carotid sinus buffering.
mesh_terms: D000818:Animals; D003331:Coronary Vessels / Q000502:physiology; D003714:Denervation; D004285:Dogs; D005260:Female; D006470:Hemorrhage / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply* / Q000201:enzymology; D008297:Male; D012039:Regional Blood Flow; D012083:Renin / Q000378:metabolism*; D014630:Vagus Nerve / Q000502:physiology
chemical_list: D012083:Renin