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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, METHODS, RESULTS. Meshes: Aldosterone, Animal Feed, Animals, Autoradiography, Blood Pressure, Disease Models, Animal, Hypertension, Renal, Hyperuricemia, Male, Nephrectomy, Oxonic Acid, Rats, Rats, Sprague-Dawley, Receptor, Angiotensin, Type 1, Receptor, Angiotensin, Type 2, Renal Insufficiency, Chronic, Renin-Angiotensin System, Reverse Transcriptase Polymerase Chain Reaction, Uric Acid.
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Does oxonic acid-induced hyperuricemia elevate plasma aldosterone in experimental renal insufficiency? Context: 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. We examined the effects of hyperuricemia on circulating and renal components of the renin-angiotensin-aldosterone system in experimental renal insufficiency. 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. 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.
assistant
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. Final Decision: yes