Increased plasma free tryptophan levels in human cancer: a tumor related effect?
High free tryptophan (F-TRP) plasma levels are found in cancer patients (CP). F-TRP plasma concentrations are affected by the levels of its carrier, albumin (ALB), and free fatty acids (FFA) competing with TRP for ALB binding sites. The lack of correlation between F-TRP, ALB and FFA in CP suggests a tumor-dependent effect on the rise in F-TRP. To verify this hypothesis, F-TRP, ALB and FFA levels were assayed in 12 lung and 16 breast CP susceptible to radical surgery, before and 15 days after surgical removal of the tumor. F-TRP levels significantly decreased after tumor ablation. Since no correlation was found between F-TRP, ALB and FFA variations, it is conceivable that the tumor itself may be responsible for the high F-TRP levels in CP.
Cascino
A
A
III Department of Internal Medicine, University of Rome, La Sapienzo, Italy.
Cangiano
C
C
Ceci
F
F
Franchi
F
F
Mineo
T
T
Mulieri
M
M
Muscaritoli
M
M
Rossi Fanelli
F
F
D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012709:Serum Albumin / Q000032:analysis; D014364:Tryptophan / Q000097:blood*
D014408:Biomarkers, Tumor; D005230:Fatty Acids, Nonesterified; D012709:Serum Albumin; D014364:Tryptophan