title: Effects of intraluminal hydrostatic pressure on L-methionine absorption in the obstructed small intestine of the rat.
abstract: The effects of elevated intraluminal hydrostatic pressure on the active absorption of the amino acid selenium 75 L-methionine has been analyzed in the normal and obstructed small intestine. An intestinal loop of defined position and length was included in a recircling perfusion system from which the elimination rate of the radiolabeled amino acid was measured. Preset pressure levels within the system were maintained by a servo-controlled unit, which added or subtracted volume to keep the pressure constant. The rate of amino acid elimination increased when the nonobstructed loop was subjected to a pressure of 10 cm H2O but decreased when exposed to 20cm H2O. Using a loop of intestine subjected to 48 hours of obstruction, amino acid elimination was greatly retarded compared with that of the nonobstructed loop. By increasing the intraluminal pressure to 10 and 20 cm H2O, the elimination rate increased, equalling that of the nonobstructed gut. The results suggest that intestinal obstruction per se decreases active absorption secondary to impaired intestinal viability. Moderately increased intraluminal pressure adds a driving force to L-methionine absorption, the mechanism of which is obscure.
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005069:Evaluation Studies as Topic; D006400:Hematocrit; D006874:Hydrostatic Pressure; D007077:Ileal Diseases / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007408:Intestinal Absorption; D007415:Intestinal Obstruction / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000378:metabolism*; D011312:Pressure; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D012044:Regression Analysis; D012643:Selenium
chemical_list: D011868:Radioisotopes; D008715:Methionine; D012643:Selenium