Rat gastric procolipase: sequence, expression, and secretion during high-fat feeding.
OBJECTIVE
Procolipase, the cofactor for pancreatic lipase, was recently found in the rat stomach using immunohistochemistry. The aim of this study was to determine the sequence of rat gastric procolipase, to evaluate the expression and secretion during high-fat feeding, and to find out the conditions for activation of gastric procolipase to form colipase and enterostatin.


METHODS
Gastric procolipase was cloned from a rat complimentary DNA (cDNA) library using a 32P-labeled pancreatic procolipase probe for screening. For the expression of gastric procolipase, rats were fed a high-fat diet for 0, 1, 2, 5, and 14 days. Gastric mucosa was collected for isolation of RNA and gastric juice for measurement of procolipase. After treatment with pepsin, HCl, and trypsin, gastric juice was analyzed on high-performance liquid chromatography for identification of enterostatin.


RESULTS
The cDNA sequence for gastric procolipase was identical to that of pancreatic procolipase. High-fat diet decreased the expression of gastric procolipase. Enterostatin was present in the gastric juice, with pepsin and acid involved in the cleavage of gastric procolipase.


CONCLUSIONS
Gastric procolipase is activated to release colipase and enterostatin. The role of gastric colipase may be to prepare lipase-catalyzed fat digestion already in the stomach. Gastric enterostatin may be involved in the onset of early satiety.
Winzell
M S
MS
Section for Molecular Signaling, Department of Cell and Molecular Biology, University of Lund, Lund, Sweden. Maria.Sorhede@medkem.lu.se
Lowe
M E
ME
Erlanson-Albertsson
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003089:Colipases / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D004789:Enzyme Activation; D004792:Enzyme Precursors; D005750:Gastric Juice / Q000737:chemistry; D008297:Male; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000187:drug effects / Q000201:enzymology*
D003089:Colipases; D018076:DNA, Complementary; D004041:Dietary Fats; D004792:Enzyme Precursors; D011498:Protein Precursors; C037107:procolipase