Oxonic acid-induced hyperuricemia elevates plasma aldosterone in experimental renal insufficiency.
J Hypertens
; 26(8): 1661-8, 2008 Aug.
Article
em En
| MEDLINE
| ID: mdl-18622246
ABSTRACT
BACKGROUND:
Hyperuricemia is associated with renal insufficiency and may predispose to Na retention and hypertension. Whether hyperuricemia plays a causal role in the pathogenesis of cardiovascular disease remains controversial.OBJECTIVE:
We examined the effects of hyperuricemia on circulating and renal components of the renin-angiotensin-aldosterone system in experimental renal insufficiency.METHODS:
Three weeks after 5/6 nephrectomy or sham-operation, rats were put on 2.0% oxonic acid diet for 9 weeks. Blood pressure was monitored using tail-cuff, and blood, urine, and kidney samples were taken, as appropriate. Kidney angiotensin-converting enzyme, angiotensin-converting enzyme 2 and angiotensin II receptors (AT1R, AT2R) were examined using real-time reverse transcriptase-PCR and autoradiography.RESULTS:
Oxonic acid diet increased plasma uric acid by 80-90 micromol/l, while blood pressure was elevated only in hyperuricemic 5/6 nephrectomy rats (18 mmHg). Creatinine clearance was reduced by 60% in both 5/6 nephrectomy groups and by 25% in hyperuricemic Sham rats. The 5/6 nephrectomy group showed over 90% suppression of plasma renin activity, whereas the Sham + oxonic acid diet group showed 1.2 and 1.4-fold, and 5/6 nephrectomy + oxonic acid diet group 2.5 and 2.3-fold increases in plasma renin activity and plasma aldosterone, respectively. Hyperuricemia increased K and decreased Na excretion in Sham and 5/6 nephrectomy rats, leading to a more than 1.6-fold increase in urine K to Na ratio. No changes in kidney angiotensin-converting enzyme, angiotensin-converting enzyme 2, AT1R or AT2R were detected that could explain the hyperuricemia-induced alteration in Na-K balance.CONCLUSION:
As oxonic acid diet increased plasma renin activity, plasma aldosterone, and urine K to Na ratio, these changes may play a significant role in the harmful cardiovascular actions of hyperuricemia.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ácido Oxônico
/
Hiperuricemia
/
Aldosterona
/
Insuficiência Renal Crônica
/
Hipertensão Renal
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article