title: Cardiac hypertrophy and performance of Dahl hypertensive rats on graded salt diets.
abstract: The relationship between arterial pressure and left ventricular (LV) functional capacity and LV mass during the natural development of cardiac hypertrophy was assessed in Dahl-resistant (R) and -sensitive (S) hypertensive rats maintained on three dietary NaCl regimens (0.4%, 4.0%, and 8.0% for 9 weeks, then 4.0%) from 5 until 20 weeks of age. In R rats, arterial pressure and LV mass were unaffected by diet. In contrast, S rats demonstrated levels of arterial pressure and LV hypertrophy that were graded according to dietary NaCl. Hemodynamic studies on rats under ether anesthesia demonstrated that the graded pressure elevation in S rats was produced by corresponding increases in total peripheral resistance, as cardiac output did not vary. During acute volume loading, the S rats on all diets achieved the same maximum stroke volume as did R rats, despite the marked increase in the arterial pressure of S rats. An analysis of the ejection fraction/afterload relationship demonstrated preserved contractile state. The ability of the left ventricle to generate pressure was increased in S rats in direct proportion to the degree of LV hypertrophy. Thus, in young adult S rats, cardiac performance was well compensated since pump and contractile functions were maintained and pressure-generating capacity was increased in relation to the degree of LV hypertrophy.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D006332:Cardiomegaly / Q000473:pathology / Q000503:physiopathology*; D004032:Diet; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology*; D013318:Stroke Volume / Q000187:drug effects
chemical_list: D012965:Sodium Chloride