Altered small intestinal absorptive enzyme activities in leptin-deficient obese mice: influence of bowel resection.
BACKGROUND
Residual bowel increases absorption after massive small bowel resection. Leptin affects intestinal adaptation, carbohydrate, peptide, and lipid handling. Sucrase, peptidase, and acyl coenzyme A:monoacylglycerol acyltransferase (MGAT) are involved in carbohydrate, protein, and lipid absorption. We hypothesized that leptin-deficient obese mice would have altered absorptive enzymes compared with controls before and after small bowel resection.


METHODS
Sucrase, peptidase (aminopeptidase N [ApN], dipeptidyl peptidase IV [DPPIV]), and MGAT activities were determined from lean control (C57BL/6J, n = 16) and leptin-deficient (Lep(ob), n = 16) mice small bowel before and after 50% resection.


RESULTS
Ileal sucrase activity was greater in obese mice before and after resection. Jejunal ApN and DPPIV activities were lower for obese mice before resection; ileal ApN activity was unaltered after resection for both strains. Resection increased DPPIV activity in both strains. Jejunal MGAT in obese mice decreased postresection. In both strains, ileal MGAT activity decreased after resection, and obese mice had greater activity in remnant ileum.


CONCLUSIONS
After small bowel resection, leptin-deficient mice have increased sucrase activity and diminished ileal ApN, DPPIV, and MGAT activity compared with controls. Therefore, we conclude that leptin deficiency alters intestinal enzyme activity in unresected animals and after small bowel resection. Altered handling of carbohydrate, protein, and lipid may contribute to obesity and diabetes in leptin-deficient mice.
Kiely
James M
JM
Department of Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Noh
Jae H
JH
Svatek
Carol L
CL
Pitt
Henry A
HA
Swartz-Basile
Deborah A
DA
D000217:Acyltransferases / Q000096:biosynthesis; D000818:Animals; D007408:Intestinal Absorption / Q000502:physiology*; D007421:Intestine, Small / Q000201:enzymology* / Q000503:physiopathology / Q000601:surgery; D020738:Leptin / Q000172:deficiency* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000201:enzymology* / Q000503:physiopathology; D010447:Peptide Hydrolases / Q000096:biosynthesis; D013393:Sucrase / Q000096:biosynthesis
D020738:Leptin; D000217:Acyltransferases; C021802:2-acylglycerol O-acyltransferase; D013393:Sucrase; D010447:Peptide Hydrolases