title: The causative agent in atrial receptor diuresis in the dog is a low molecular weight, lipophilic and weakly acidic substance.
abstract: Stimulation of atrial receptors by distension of a balloon in the left atrium of anaesthetized dogs results in a reflex diuresis mediated by a humoral agent of unknown identity. In previous investigations, a substance was recovered in a low molecular weight fraction from Bio-Gel P-2 (100-1800 daltons) and shown to be related to the reflex diuresis. In this investigation, the active Bio-Gel P-2 fraction was partitioned with ethyl acetate at pH 11.0, with subsequent partition of the aqueous phase with ethyl acetate at pH 7.4; the activity of the humoral agent was soluble in ethyl acetate at pH 7.4. These investigations suggest that the humoral agent is a low molecular weight, lipophilic and weakly acidic substance. The substance is not antidiuretic hormone (ADH) as vasopressin is insoluble in ethyl acetate at pH 7.4.
mesh_terms: D000085:Acetates; D000818:Animals; D016275:Atrial Function; D002850:Chromatography, Gel; D004231:Diuresis; D004285:Dogs; D006325:Heart Atria / Q000294:innervation; D006863:Hydrogen-Ion Concentration; D008465:Mechanoreceptors / Q000502:physiology*; D008970:Molecular Weight; D012239:Rhodnius; D014667:Vasopressins
chemical_list: D000085:Acetates; D014667:Vasopressins; C007650:ethyl acetate