When glucose is unused, it is metabolized via the polyol pathway. This pathway consists of two main enzymatic steps. First, glucose is reduced to sorbitol by aldose reductase. In this step, NADPH is oxidized to NADP+. The next step is the oxidation of sorbitol to D-fructose by sorbitol dehydrogenase.
Fructose can then be phosphorylated by fructokinase and subsequently be metabolized via dihydroxyacetone phosphate or glyceraldehyde to D-glyceraldehyde 3-phosphate, which can be used as a substrate in the process of glycolysis.
The sorbitol pathway plays a role in diabetic renal complications because aldose reductase metabolizes the excess of glucose to toxic metabolites that induce hyperfiltration and glomerular dysfunction.
Metabolic Process
This pathway was inferred from Homo sapiens pathway [http://wikipathways.org/instance/WP690_r72132 WP690(72132)] with a 100.0% conversion rate.
ccc
e59
f60
HomologyConvert: Homo sapiens to Bos taurus: Original ID = En:ENSG00000140263
HomologyConvert: Homo sapiens to Bos taurus: Original ID = En:ENSG00000138030
HomologyConvert: Homo sapiens to Bos taurus: Original ID = L:231
HomologyConvert: Homo sapiens to Bos taurus: Original ID = En:ENSG00000136872
10997684
PubMed
Aldose reductase and the role of the polyol pathway in diabetic nephropathy.
Kidney Int Suppl
2000
Dunlop M
8535439
PubMed
Molecular basis of hereditary fructose intolerance: mutations and polymorphisms in the human aldolase B gene.
Hum Mutat
1995
Tolan DR
glucose utilization pathway
PW:0000555
Pathway Ontology
11742414
PubMed
Biochemistry and molecular cell biology of diabetic complications.
Nature
2001
Brownlee M
kidney disease pathwayPW:0000300Pathway Ontologydiabetes mellitusDOID:9351Diseaseglucose oxidation pathwayPW:0000556Pathway Ontology