[Disorders of uric acid metabolism in rats with fructose-induced experimental insulin resistance syndrome].

Consumption of dietary fructose has been recently suggested to be one of the environmental factors contributing to development of obesity and accompanying abnormalities of the insulin resistance syndrome (IRS). IRS was induced in rats by adding 10% fructose to drinking water. Within 8 wk insulin resistance, carbohydrate metabolism disorder, weight gain, hypertrigyceridemia and hyperuricemia were developed. The signs of IRS were more pronounced in male than in female rats. An increase of uric acid (UA) daily excretion was revealed only in males, suggesting a hyperproductoin of UA. There was not significant disorder of kidney filtration, although an increase of UA clearance was revealed due to enhanced kidney urate reabsorbtion which may be connected to the hypouricosuric action of insulin but not the testosterone level changes. It was first revealed an increased activity of enzymes catalyzing early stages of purine catabolism (5'-nucleotidase and adenosindesaminase) in liver homogenate. Activity of enzyme of purine reutilisatoin (hypoxantin-guanine-phosphoribosil transferase) was found increased that may have a compensatory significance under conditions of increased purine degradation.

[Interrelations of uric acid metabolism indices with insulin and testosterone levels in men with type 2 diabetes].

95 men aged 45-65, suffering from type 2 diabetes for 0.1-20 years (4.5 +/- 1.4) were examined. Hypoandrogenia (serum testosterone < 10,4 nmol/ml) was noted in 37% of investigated patients. Hyperuricemia (HUA), defined by serum uric acid (UA) content more than 450 pmol/L, was detected in 34% of subjects. In 74% of patients there was a high level of 24h UA urine excretion (UA(u) > 4.43 mmol), suggesting a hyperproduction of UA. Because the level of uricemia is defined by UA production and extretion, we outline two main types of alterations in UA metabolism: normouricemic, hyperuricosuric and hyperuricemic. In normouricemic and hyperuricosuric men UA excretion growth in parallel with the rate of kidney filtration, obesity, glycemia. High urate elimination index (UEI) suggests a decrease of UA reabsorption in kidney. The results allow us to suggest a significance of insulin and testosterone influence on regulation of UA metabolism in aged men with type 2 diabetes and insulin resistance syndrome.

[Peculiarities of uric acid balance disorders in patients with type 2 diabetes and metabolic syndrome].

Hyperuricemia (HU) is considered to be a sign of metabolic syndrome as a consequence of purine metabolism disorder. To investigate alterations in uric acid (UA) methabolism, 90 subjects (M/F 53/37, aged 58 +/- 4 yr) with type 2 diabetes mellitus (DM2) were divided into 5 groups depending on the amount of excreted UA and its content in blood plasma. HU was found in 29% of patients, while hyperpoduction of UA was characteristic in 87% patients. Normo- or hypouricemia in majority of patients were mostly connected to kidney hyperfiltration and "compensatory" hyperuricosuria. HU with decreased UA excretion ("kidney" HU) was characteristic of severe DM2 with reduced kidney filtration rate. "Metabolic" HU with increased formation and excretion rated of UA was observed only in obese men. Increased insulinemia levels and insulin resistance index (IR) were found in obese patients in comparison with subjects with normal weight, independently of the type of UA excretion disorder. IR strongly correlated with serum UA levels in all groups of patients. The results suggest the significance of insulin resistance and abdominal obesity in UA metabolism in DM2.