Baroreflex control of heart rate in young and adult salt hypertensive inbred Dahl rats
Language English Country Czech Republic Media print
Document type Comparative Study, Journal Article, Research Support, Non-U.S. Gov't
PubMed
11043919
Knihovny.cz E-resources
- MeSH
- Baroreflex drug effects physiology MeSH
- Phenylephrine pharmacology MeSH
- Hypertension chemically induced physiopathology MeSH
- Blood Pressure drug effects physiology MeSH
- Rats MeSH
- Sodium Chloride, Dietary pharmacology MeSH
- Rats, Inbred Dahl MeSH
- Heart Rate drug effects physiology MeSH
- Sympathomimetics pharmacology MeSH
- Age Factors MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
- Names of Substances
- Phenylephrine MeSH
- Sodium Chloride, Dietary MeSH
- Sympathomimetics MeSH
Baroreflex control of heart rate was studied in inbred salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) Dahl rats that were subjected to chronic dietary sodium chloride loading (for 4 weeks) either in youth or only in adulthood, i.e. from the age of 4 or 12 weeks. Using phenylephrine administration to pentobarbital-anesthetized male rats we have demonstrated the decreased baroreflex sensitivity (lower slope for reflex bradycardia) in young prehypertensive SS/Jr rats fed a low-salt diet as compared to age-matched SR/Jr animals. High salt intake further suppressed baroreflex sensitivity in young SS/Jr but not in SR/Jr rats. Baroreflex sensitivity decreased with age in SR/Jr rats, whereas it increased in SS/Jr rats fed a low-salt diet. Thus at the age of 16 weeks baroreflex sensitivity was much higher in SS/Jr than in SR/Jr animals. High salt intake lowered baroreflex sensitivity even in adult SS/Jr rats without affecting it in adult SR/Jr rats. Nevertheless, baroreflex sensitivity was significantly lower in young SS/Jr rats with a severe salt hypertension than in adult ones with a moderate blood pressure elevation. It is concluded that the alterations of baroreflex sensitivity in young inbred SS/Jr rats (including the response to high salt intake) are similar to those described earlier for outbred salt-sensitive Dahl rats. We have, however, disclosed contrasting age-dependent changes of baroreflex sensitivity in both inbred substrains of Dahl rats.
Altered Balance between Vasoconstrictor and Vasodilator Systems in Experimental Hypertension
Research on Experimental Hypertension in Prague (1966-2009)
