Premium
Stimulation of Intestinal Arginine Absorption in Tumor‐Bearing Rats
Author(s) -
Meng Qinghe,
Choudry Harron M,
Lin Chengmao,
Karinch Anne M,
Souba Wiley W,
Pan Ming
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a349-d
Subject(s) - stimulation , arginine , bearing (navigation) , absorption (acoustics) , medicine , chemistry , endocrinology , neuroscience , biology , biochemistry , amino acid , optics , physics , astronomy
Background Arginine plays a pivotal role in ureagenesis, polyamine biosynthesis, and nitric oxide biosynthesis. Intestinal absorption of exogenous arginine is key in maintaining arginine homeostasis. The present study was designed to investigate the effect of fibrosarcoma on intestinal arginine absorption in tumor‐bearing rats (TBR). Method Fibrosarcoma cells were implanted in Fisher 344 rats and tumors were allowed to grow to 5%, 10%, or 15% of total body weight. Control and tumor‐bearing rats were pair‐fed throughout the study. Jejunal epithelia brush border membrane vesicles (BBMV) and epithelial cell RNA were then isolated. Intestinal arginine absorption was measured using [H 3 ]‐L‐arginine transport into BBMV. Arginine transport System y + (CAT1) mRNA and protein levels were measured using reverse transcriptase‐polymerase chain reaction (RT‐PCR) and western blots, respectively. Data is presented as mean ± standard deviation and was analyzed using ANOVA (P<0.05). Result Arginine absorption capacity was elevated in all tumor‐bearing rats (5%: Control 26.0 ± 4.0 vs TBR 39.4 ± 4.1; 10%: Control 22.9 ± 1.8 vs TBR 36.2 ± 2.3; 15%: Control 20.2 ± 4.9 vs TBR 30.5 ± 2.1, pmole/mg protein/30 seconds). There was no significant difference in arginine transport capacity among the tumor‐bearing rats. The predominant arginine transport System y + (CAT1) level was also elevated by 50% (CAT1/18S: Control 0.44 ± 0.07 vs TBR 0.66 ± 0.18). The arginine transporter protein level was elevated 2.5‐ fold (Control 2.5 ± 0.14 vs TBR 6.05 ± 3.04). Conclusion Fibrosarcoma growth in rats leads to increases of intestinal arginine absorption capacity, transporter mRNA abundance and transporter protein levels.