Suppressive effect of viscous dietary fiber on elevations of uric acid in serum and urine induced by dietary RNA in rats is associated with strength of viscosity.
This study was performed to clarify how dietary fiber (DF) with different viscosities would be associated with dietary RNA metabolism. Male Wistar strain rats, four weeks old, were fed diets containing a 3% (w/w) yeast RNA and a 5% (w/w) viscous DF for five days. Viscosity of DF samples used, in order of strength, were xanthan gum (XG) > guar gum (GG) > locust bean gum (LBG) > karaya gum (KG) > pectin (PE) = arabic gum (AG) > CM-cellulose (CMC) = inulin (IN). The serum uric acid concentration in the viscous DF groups significantly decreased as compared with that in the cellulose (CL) group. The urinary excretions of uric acid and allantoin in the respective groups given AG, GG, IN, KG, PE, and XG were significantly suppressed as compared with those in the CL group. The fecal RNA excretion was markedly increased in the IN, KG, PE, and XG groups in comparison to the CL group. The DF with high viscosity significantly suppressed RNA digestion by RNase A and decreased uptakes of 14C-labeled adenosine and adenosine 5'-monophosphate (5'-AMP) in rat jejunum. The results reveal that the suppressive effect of DF on elevation of serum uric acid concentration induced by dietary RNA in rats is associated with the strength of DF viscosity. The mechanism by which this is accomplished is suggested to be attributed to the inhibitions of digestion for dietary RNA and/or absorption of the hydrolyzed compounds.
Koguchi
Takashi
T
Department of Applied Biology and Chemistry, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan. tad16613@nodai.ac.jp
Nakajima
Hisao
H
Koguchi
Hiromi
H
Wada
Masahiro
M
Yamamoto
Yuji
Y
Innami
Satoshi
S
Maekawa
Akio
A
Tadokoro
Tadahiro
T
D000249:Adenosine Monophosphate / Q000378:metabolism; D000481:Allantoin / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002482:Cellulose / Q000008:administration & dosage; D003838:Deoxyadenine Nucleotides / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage* / Q000145:classification; D004063:Digestion / Q000187:drug effects; D005243:Feces / Q000737:chemistry; D005503:Food Additives / Q000008:administration & dosage; D005685:Galactans / Q000008:administration & dosage; D006170:Gum Arabic / Q000008:administration & dosage; D006868:Hydrolysis / Q000187:drug effects; D007421:Intestine, Small / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D007474:Ion Exchange; D007618:Karaya Gum / Q000008:administration & dosage; D008297:Male; D008351:Mannans / Q000008:administration & dosage; D023421:Models, Animal; D009929:Organ Size / Q000187:drug effects; D010368:Pectins / Q000008:administration & dosage; D053149:Plant Gums; D011134:Polysaccharides / Q000008:administration & dosage; D011135:Polysaccharides, Bacterial / Q000008:administration & dosage; D012313:RNA / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013223:Statistics as Topic; D014014:Tissue Adhesives / Q000008:administration & dosage; D014527:Uric Acid / Q000378:metabolism*; D014783:Viscosity
D015415:Biomarkers; D003838:Deoxyadenine Nucleotides; D004043:Dietary Fiber; D005503:Food Additives; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D014014:Tissue Adhesives; D014527:Uric Acid; D000481:Allantoin; D000249:Adenosine Monophosphate; D012313:RNA; D010368:Pectins; D006170:Gum Arabic; D007618:Karaya Gum; D002482:Cellulose; C007894:guar gum; C026600:2'-deoxyadenosine triphosphate; C002563:xanthan gum; C017471:locust bean gum