title: Plasma atrial natriuretic peptide and blood pressure during chronic salt loading in spontaneously hypertensive rats with right atrial appendectomy.
abstract: Spontaneously hypertensive rats (SHR) were subjected to right atrial appendectomy (ATRX) or sham operated. Five days after this procedure the rats were put on tap water or 1.5% NaCl as drinking water for 1 week. The blood pressure (carotid artery), 24 hours urinary sodium and kalium excretion, plasma levels of immunoreactive atrial natriuretic peptide (ir-ANP) and the rise in plasma ir-ANP concentrations after an acute volume expansion by homologous whole blood (10%) were evaluated after 1 week on the different diets. At the start of the dietary period the rise in plasma ir-ANP values was blunted in ATRX rats. After 1 week the salt loaded animals excreted tenfold more sodium than control rats. At this time basal ir-ANP values in plasma were not significantly influenced by the ATRX and/or the high salt diet but the rise in plasma ir-ANP concentrations to acute volume expansion was blunted in the salt loaded rats. However, the basal blood pressure was not influenced by the salt diet and/or the ATRX. These data do not support the notion that an alleged deficiency in ANP release mechanisms in the SHR is a major determinant for the blood pressure development in this rat strain.
mesh_terms: D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001794:Blood Pressure / Q000187:drug effects*; D004573:Electrolytes / Q000652:urine; D006325:Heart Atria / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology / Q000652:urine; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D012965:Sodium Chloride / Q000008:administration & dosage* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D004573:Electrolytes; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor