Effects of nucleosides and a nucleotide mixture on gut mucosal barrier function on parenteral nutrition in rats.
BACKGROUND
We have previously reported that the addition of nucleosides and a nucleotide mixture (OG-VI) to total parenteral nutrition (TPN) prevents TPN-induced intestinal mucosal atrophy and results in increased intestinal cathepsin activities under TPN. The aims of the present study are to examine the effects of OG-VI on mucosal barrier functions and to clarify whether the intestinal cathepsins can be used as a new marker of mucosal barrier function.


METHODS
Male Wistar rats were divided into three groups: FED (food ad libitum), TPN (a standard TPN solution), and OG (OG-VI in addition to the TPN solution). Mucosal barrier functions were analyzed by the lactulose/mannitol (L/M) test, mucosal ZO-1 messenger RNA level, and electron micrographs in the gut. Intestinal cathepsin B, H, and L activities were also measured.


RESULTS
The L/M ratio for TPN was much higher than that for FED. Only lactulose excretion was significantly reduced by OG-VI. The intercellular spaces of the mucosal cells for TPN were significantly wider than those for FED, but were reduced in size by the addition of OG-VI. All cathepsin activities of the ileum were higher for TPN than for FED, whereas OG showed no increase.


CONCLUSIONS
OG-VI contributes to the improvement of gut mucosal barrier function. Intestinal cathepsin activities can be used as a new marker of mucosal barrier function.
Kishibuchi
M
M
Department of Surgery II, Osaka University Medical School, Suita, Japan.
Tsujinaka
T
T
Yano
M
M
Morimoto
T
T
Iijima
S
S
Ogawa
A
A
Shiozaki
H
H
Monden
M
M
D000818:Animals; D001284:Atrophy; D018988:Bacterial Translocation / Q000502:physiology; D015152:Blotting, Northern; D002403:Cathepsins / Q000032:analysis / Q000235:genetics / Q000502:physiology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis / Q000235:genetics / Q000502:physiology; D007082:Ileum / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure; D007150:Immunohistochemistry; D007365:Intercellular Junctions / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009705:Nucleosides / Q000494:pharmacology*; D009711:Nucleotides / Q000494:pharmacology*; D010289:Parenteral Nutrition, Total; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D009705:Nucleosides; D009711:Nucleotides; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D002403:Cathepsins