The role of the cardiac nerves in the regulation of sodium excretion in conscious dogs

摘要: Conscious, chronically instrumented dogs, maintained on a high sodium intake, were used to investigate whether surgical cardiac denervation impairs the natriuresis associated with left atrial pressure increase produced in three ways: during an by means of reversible mitral stenosis (protocol 1); after i.v. saline load (1.0 ml 0.9%·saline min−1·kg−1 over 60 min) 2); oral (14.5 mmol Na·kg−1 given food as isotonic solution) 3). During stenosis, intact urine volume and excretion increased markedly (from 34–145 μl·min−1·kg−1 from 3–12 μmol·min−1·kg−1); mean arterial average 2 kPa (15 mm Hg) heart rate 55 b/min; plasma renin activity fell 0.37–0.21 ng Al·ml−1·h−1. Cardiac eliminated these effects distension except for small (12 b/min). This indicates that diuresis resulted stimulation receptors located atrium. In contrast, protocol 3, same amounts water excreted denervated dogs compared dogs. A comparable decrease also was observed. — Apparently presence nerves is not prerequisite maintenance homeostasis.