The NGN group (70 days old) was divided into four subgroups: (a) control group (C): fed standard commercial diet and water; (b) fructose group (F): fed the same diet plus 10% (w/v) fructose (Tate & Lyle, USA) in drinking water, according to previous studies ; (c) oxonic acid group (OA) (Sigma Aldrich 156124, St.
Three weeks after ovariectomy (90 days old), the HNG animals were conducted in the experimental period and were divided into the same four subgroups receiving the same treatment as the four NGN groups: (a) control group (C); (b) fructose group (F); (c) oxonic acid group (OA); and (d) fructose and oxonic acid group (FOA) (Table 1).
found that Fx significantly reduced glomerular pressure and renal vasoconstriction in fructose-induced metabolic syndrome  and oxonic
acid-induced hyperuricemic rat models .
A rat model receiving oxonic
acid, an inhibitor of uricase, has been widely used to study the pathophysiological roles of hyperuricemia [14-17].
and uric acids induced hyperuricemia in rats had shown a decrease in renal basolateral PAH uptake, corresponding to the reduction of rOat1 and 3 mRNA and protein expressions .
In animals, mild hyperuricemia induced by the uricase inhibitor oxonic
acid, mimicking levels in humans, increased blood pressure by crystal-independent mechanism resulting in stimulation of the renin-angiotensin system and inhibition of nitric oxide synthase .
In one such model, rats were treated with oxonic
acid (a uricase inhibitor) to approximate the human situation, in which our evolutionary loss of uricase resulted in increases in serum urate levels.
The NGN groups were divided into four subgroups: (a) control group (C): fed with a standard commercial diet and water; (b) fructose group (F): fed with the same diet plus 10% (w/v) fructose (Tate&Lyle, USA) in the drinking water for 5 weeks; (c) oxonic
acid group (OA) (Sigma Aldrich 156124, St.
(24) Indeed, rats treated with oxonic
acid (a uricase inhibitor) simultaneously experience a rise in serum urate and a fall in serum nitric oxide, an effect that can be reversed with the lowering of uric acid by allopurinol (a xanthine oxidase inhibitor).
Animal model experiments demonstrate that high level of uric acid in normal rats induced by the uricase inhibitor, oxonic
acid, results in hypertension and vascular disease.
The investigators then treated the animals with oxonic
acid, a uricase inhibitor, and the rats' blood pressure returned to normal or higher than normal levels.
(16) Serum urate also has been implicated in hypertension by a series of studies in rats treated with the uricase inhibitor oxonic