Glucocorticoid regulation of rat liver urate oxidase

Abstract

Urate oxidase, an enzyme involved in purine catabolism, comprises the crystalline core of rat liver peroxisomes. An affinity-purified monospecific antibody was developed to study the expression of urate oxidase protein levels. Immunoreactive urate oxidase was not detectable in prenatal liver; however, it is present at low levels after birth until approximately day 15 (postnatal age); expression sharply increases just prior to day 20, after which the enzyme is maintained at adult levels. This pattern of expression was similar to that of another peroxisomal enzyme, catalase; these developmental increases reflect the increase in peroxisomal number. Administration of exogenous glucocorticoid hormone to 10-day-old rats resulted in a precocious rise (2.5-fold) in urate oxidase levels. Adrenalectomy at 10 days of age did not cause decreased levels in the fourth week of life. In adult animals, while exogenous glucocorticoid administration did not influence urate oxidase levels, adrenalectomy at 60 days of age decreased urate oxidase levels to 40 percent of control levels. Subsequent administration of exogenous glucocorticoid hormone restored urate oxidase to normal levels. Parallel studies of catalase levels indicate that this glucocorticoid-sensitive response is not generalized for all peroxisomal proteins. Our results suggest that peroxisomes proliferate during early postnatal development, but after this process is complete, the biogenesis of individual peroxisomal proteins may be independently regulated.

Peroxisomal biogenesis is genetically and biochemically linked to carbohydrate metabolism in Drosophila and mouse

“…Strikingly, dicarboxylic fatty acids of different chain lengths were among the most severely (5–10 fold increased from mutant to rescue lines) and consistently deregulated metabolites ( Fig 5A ). Moreover, defects in purine catabolism were also consistent in the pex2 and pex16 mutants [55]( Fig 5C ). Therefore, the untargeted metabolic profiling identified defects in a number of pathways already implicated in peroxisomal biochemistry.…”

Non-enzymatic sensing of uric acid using a carbon nanotube ionic-liquid paste electrode modified with poly(β-cyclodextrin)

“…The abnormal concentration levels of uric acid indicate the symptoms of diseases such as gout, hyperuricemia, and Lesch-Nyhan syndrome [1]. Therefore, it is important to detect uric acid selectively and simply in the diagnosis and treatment of diseases.…”

An Amperometric Biosensor for Uric Acid Determination Prepared From Uricase Immobilized in Polyaniline-Polypyrrole Film

“…serum and urine) is a clinically valuable diagnostic indicator [1]. The presence of elevated uric acid levels is a sign of gout, hyperuricemia, or Lesch-Nyhan syndrome [2]. Similarly, elevated uric acid levels are related to other conditions including increased alcohol consumption, obesity, diabetes, high cholesterol, kidney disease, and heart diseases.…”