Age-dependent changes of baroreflex efficiency in Dahl rats: effects of high salt intake.
The age-dependent changes in baroreflex control of heart rate were studied in inbred Dahl rats. At the age of 8 weeks the baroreflex slope was significantly greater in salt-resistant (R/Jr) than in salt-sensitive (S/Jr) rats fed a low-salt diet. The reverse was true in 16-week-old animals. High salt intake (8% NaCl diet for 4 weeks) suppressed baroreflex efficiency in both age groups of S/Jr animals whereas no effects occurred in R/Jr rats. Baroreflex slope was, however, significantly lower in young S/Jr rats with a severe form of salt hypertension than in adult salt-loaded S/Jr rats in which only a moderate blood pressure elevation was observed.
Nedvídek
J
J
Institute of Physiology, Czech Academy of Sciences, Prague.
Zicha
J
J
D000375:Aging / Q000502:physiology*; D000818:Animals; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D005838:Genotype; D006339:Heart Rate / Q000502:physiology; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012982:Sodium, Dietary / Q000494:pharmacology*
D012982:Sodium, Dietary; D010656:Phenylephrine