engleski

HPLC determination os free sphinganinesphingosine in serum and urine of individuals from the endemic nephropathy area in Croatia

Endemic nephropathy is a chronic renal disease with a high prevalence in a geographically limited area of Croatia, Brodska Posavina. Despite numerous studies conducted to date, the etiology of this disease has not yet been clarified. During the past few years, the mycotoxin hypothesis has prevailed. The present research is based on the knowledge of effects of fumonisins, mycotoxins produced by Fusarium moniliforme on sphingolipid metabolism in mammals. These mycotoxins have been shown to be a potent inhibitors of ceramide synthase, an enzyme of de novo sphingolipid biosynthesis, resulting in the elevated sphinganine/sphingosine ratio. The aim of our research was to establish if the change in the concentrations of free sphinganine and sphingosine, as well as their ratio could be related to endemic nephropathy. Free sphingoid bases were obtained by base hydrolysis of complex sphingolipids from serum and urine, derivatised with the OPA (O-Phtaldialdehyde) reagent and analysed by high performance liquid chromatography (RP C18 column, fluorescence detector, CH3OH:H2O= 90:10 as the mobile phase, 2 mL/min). In the serum of the tested individuals from the endemic area (individuals belonging to the suspected and affected groups), a significant increase in the concentration of free sphinganine and sphingosine has been found in comparison with control group (individuals from nonendemic area). A significant increase in the sphinganine/sphingosine ratio has been found in urine of healthy man and those from the affected and suspected groups, and in urine of women from affected and suspected groups. These results point to disorder in sphingolipid metabolism, probably induced by fumonisins and/or related mycotoxins. Our data suggest that the change in the concentration of analysed sphingoid bases as well as in their ratio might precede endemic nephropathy.

endemic nephropathy; sphinganine; sphingosine; HPLC

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