Early regional expression and secretion of peptide YY and enteroglucagon after massive resection of small bowel.
BACKGROUND
Previous studies suggest that peptide YY (PYY) and enteroglucagon have an important role in intestinal adaptation after massive small bowel resection. This study was done to define the mechanisms, timing, and anatomic distribution of the PYY and enteroglucagon response.


METHODS
Lewis rats underwent resection of 70 percent of the small bowel (leaving equal segments of jejunum and ileum), transection, or laparotomy alone. Jejunum, ileum, and colon were compared in resected, transected, and control bowel six hours, 24 hours, one week, and two weeks postoperatively.


RESULTS
Analysis of DNA, RNA, and protein per cm of bowel demonstrated hyperplastic changes. Radioimmunoassay revealed plasma PYY and enteroglucagon to be significantly elevated 24 hours after resection and they remained so through week two. In contrast, tissue PYY and enteroglucagon content decreased significantly in all tissues (p < 0.05) after resection. Reverse transcriptase polymerase chain reaction and Southern blot analysis demonstrated an immediate and sustained increase in PYY messenger RNA (mRNA) in both the ileum (fourfold) and in the colon (2.5-fold) at six hours (p < 0.05). A gradual increase in PYY mRNA was also demonstrated in the jejunum with significance at two weeks (p < 0.05). Proglucagon mRNA was significantly higher in the jejunum, compared with the ileum and colon, at 24 hours, one week, and two weeks postresection.


CONCLUSIONS
Alterations in PYY and enteroglucagon synthesis occur early in the ileum and colon after massive small bowel resection. The residual jejunum, however, is primarily responsible for the adaptive hyperenteroglucagonemia. These findings suggest that although PYY and enteroglucagon are colocalized to the same cell type, there is a gene-specific response for these two peptides after resection.
Bilchik
A J
AJ
Department of Surgery, University of California Los Angeles School of Medicine, USA.
Hines
O J
OJ
Adrian
T E
TE
Skotzko
M J
MJ
McFadden
D W
DW
Zinner
M J
MJ
Ashley
S W
SW
D000222:Adaptation, Physiological; D000818:Animals; D015139:Blotting, Southern; D003106:Colon / Q000378:metabolism; D005768:Gastrointestinal Hormones / Q000096:biosynthesis / Q000235:genetics; D004763:Glucagon-Like Peptides / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism / Q000601:surgery*; D007583:Jejunum / Q000378:metabolism; D010452:Peptide Biosynthesis; D019894:Peptide YY; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011917:Rats, Inbred Lew
D005768:Gastrointestinal Hormones; D010455:Peptides; D012333:RNA, Messenger; D019894:Peptide YY; D004763:Glucagon-Like Peptides