Effect of abdominal irradiation on the kinetic parameters of intestinal uptake of glucose, galactose, leucine, and gly-leucine in the rat.
A previously validated in vitro technique was used to determine the effect of abdominal irradiation on the intestinal uptake (Jd) of glucose, galactose, leucine, and gly-leucine in the rat. Three days after 600 rads from a cesium-137 source, there was a rise in the jejunal maximal transport rate (Jdm) and the apparent Michaelis constant (Km*) but a decline in the apparent passive permeability coefficient (Pd*) for glucose. Thereafter, there was a progressive decline in Km* and Jdm but a rise in Pd* for glucose uptake. In the ileum, irradiation was associated with an increased Km* and Jdm and a decreased Pd*. Fourteen days after 600 rads, Jd of leucine into the jejunum was unchanged but Jd of leucine into the ileum was increased because of a higher Pd*. The Jd of leucine from gly-leucine was greater than from leucine alone. The Jd of 0.5 to 10 mM gly-leucine into the jejunum was increased after 600 rads, whereas the greater Jd of gly-leucine into the ileum after irradiation was most marked at 40 mM. Fourteen days after 300 rads, the Jd of glucose and galactose was increased into the ileum, whereas the Jd of leucine was decreased and the Jd of these probes into the jejunum and colon was unchanged; 14 days after 900 rads, the Jd of glucose and galactose was unchanged in each site and the Jd of leucine was reduced in the ileum but not the jejunum or colon.(ABSTRACT TRUNCATED AT 250 WORDS)
D000005:Abdomen / Q000528:radiation effects; D000818:Animals; D002463:Cell Membrane Permeability / Q000528:radiation effects; D004151:Dipeptides / Q000378:metabolism; D007851:Dodecanol / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005690:Galactose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007408:Intestinal Absorption / Q000528:radiation effects*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004151:Dipeptides; D007851:Dodecanol; C015905:glycylleucine; D007930:Leucine; D005947:Glucose; D005690:Galactose