Direct spectrophotometric determination of serum fructose in pancreatic cancer patients.
OBJECTIVE
We sought to develop an assay to measure circulating fructose concentrations in pancreatic cancer patients.


METHODS
Using fructose dehydrogenase-catalyzed conversion of d-fructose to 5-ketofructose, followed by quantitation of MTT [3-(4,5-dimethylthiaze-syl)-2,5-diphenyltetrazolium bromide] formazan production by direct spectrophotometry, an assay to measure serum fructose concentration was developed, and assay sensitivity and specificity were tested. Validity of the assay was confirmed by gas chromatography-mass spectroscopy, and the assay was tested in healthy subjects and pancreatic cancer patients.


RESULTS
The assay was highly specific, exhibiting no cross-reactivity with other sugars. Mean serum fructose concentration in fasting healthy volunteers was 1.9+/-0.4 mM and after ingestion of a fructose and glucose-containing drink rose to 16.3+/-1.2 mM at 15 minutes and peaked at 30 minutes when serum fructose was 17.2+/-1.1 mM. Mean fasting serum fructose level was significantly higher at 5.7+/-2.5 mM in patients with pancreatic cancer than those with no pancreatic cancer. The fructose dehydrogenase-based enzymatic assay correlated highly with gas chromatography-mass spectroscopic analysis of serum fructose with a correlation coefficient of 0.94.


CONCLUSIONS
This spectrophotometric assay for fructose is easy to perform and well suited to determination of serum fructose. Measurement of serum fructose concentration may provide insight into the relationship between refined fructose intake and diseases including pancreatic cancer.
Hui
Hongxiang
H
Division of Endocrinology, David Geffen School of Medicine at UCLA, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90024, USA.
Huang
Danshan
D
McArthur
David
D
Nissen
Nicholas
N
Boros
Laszlo G
LG
Heaney
Anthony P
AP
D000368:Aged; D001774:Blood Chemical Analysis / Q000379:methods* / Q000706:statistics & numerical data; D001786:Blood Glucose / Q000378:metabolism; D002237:Carbohydrate Dehydrogenases; D016022:Case-Control Studies; D005260:Female; D005632:Fructose / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D008401:Gas Chromatography-Mass Spectrometry; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods* / Q000706:statistics & numerical data
D001786:Blood Glucose; D005632:Fructose; D002237:Carbohydrate Dehydrogenases; C028761:D-fructose 5-dehydrogenase; D005947:Glucose