Effects of succinylacetone on the uptake of sugars and amino acids by brush border vesicles

Effects of succinylacetone on the uptake of sugars and amino acids by brush border vesicles. Infants with hereditary tyrosinemia excrete succinylacetone (SA) in their urine, and suffer from a reversible renal Fanconi syndrome with glycosuria and hyperaminoaciduria. Thus, we have examined the effects of 4mM SA on rat renal brush border membrane vesicle uptake of sugars and amino acids. SA, unlike sodium maleate, significantly inhibits Na+-dependent vesicular sugar and amino acid uptake. 22Na-uptake, as well as membrane fluidity of the vesicles, are also affected by SA. Inhibition of glycine uptake by SA is reversible and competitive in nature, while α-CH3-D-glucoside uptake is non-competitively affected. We conclude, therefore, that SA has a more complex action on the rat renal tubule than sodium maleate, and is likely a much more physiologic model for study of the human renal Fanconi syndrome.