Preventive dietary potassium supplementation in young salt-sensitive Dahl rats attenuates development of salt hypertension by decreasing sympathetic vasoconstriction
Jazyk angličtina Země Velká Británie, Anglie Médium print-electronic
Typ dokumentu časopisecké články, práce podpořená grantem
- MeSH
- chlorid sodný škodlivé účinky MeSH
- draslík dietní farmakologie MeSH
- hemodynamika MeSH
- hypertenze chemicky indukované MeSH
- krevní tlak účinky léků fyziologie MeSH
- krysa rodu Rattus MeSH
- nifedipin farmakologie MeSH
- potkani inbrední Dahl MeSH
- potravní doplňky * MeSH
- sympatický nervový systém fyziologie MeSH
- vazodilatancia farmakologie MeSH
- vazokonstrikce účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chlorid sodný MeSH
- draslík dietní MeSH
- nifedipin MeSH
- vazodilatancia MeSH
AIM: Increased potassium intake attenuates the development of salt-dependent hypertension, but the detailed mechanisms of blood pressure (BP) reduction are still unclear. The aims of our study were (i) to elucidate these mechanisms, (ii) to compare preventive potassium effects in immature and adult animals and (iii) to evaluate the therapeutic effects of dietary potassium supplementation in rats with established salt hypertension. METHODS: Young (4-week-old) and adult (24-week-old) female salt-sensitive Dahl rats were fed a high-salt diet (5% NaCl) or a high-salt diet supplemented with 3% KCl for 5 weeks. The participation of vasoconstrictor (renin-angiotensin and sympathetic nervous systems) and vasodilator systems [prostanoids, Ca(2+) -activated K(+) channels, nitric oxide (NO)] was evaluated using a sequential blockade of these systems. RESULTS: Preventive potassium supplementation attenuated the development of severe salt hypertension in young rats, whereas it had no effects on BP in adult rats with moderate hypertension. Enhanced sympathetic vasoconstriction was responsible for salt hypertension in young rats and its attenuation for potassium-induced BP reduction. Conversely, neither salt hypertension nor its potassium-induced attenuation were associated with significant changes of the vasodilator systems studied. The relative deficiency of vasodilator action of NO and Ca(2+) -activated K(+) channels in salt hypertensive Dahl rats was not improved by potassium supplementation. CONCLUSIONS: The attenuation of enhanced sympathetic vasoconstriction is the principal mechanism of antihypertensive action exerted by preventive potassium supplementation in immature Dahl rats. Dietary potassium supplementation has no preventive effects on BP in adult salt-loaded animals or no therapeutic effects on established salt hypertension in young rats.
Citace poskytuje Crossref.org
Altered Balance between Vasoconstrictor and Vasodilator Systems in Experimental Hypertension
