Fractionated low doses of abdominal irradiation alters jejunal uptake of nutrients
Abdominal radiation is associated with changes in intestinal uptake of nutrients that begins within three days and persist for over 33 weeks. Clinically, fractionated doses of radiation (FDR) are used in an attempt to minimize the complications of this therapy, but the effects of fractionated doses of radiation on intestinal transport have not been defined. An in vitro technique was used to assess the jejunal and ileal uptake of varying concentrations of glucose and leucine, as well as the uptake of single concentrations of fatty acids and decanol in rats exposed 3, 7, and 14 days previously to a course of 200 cGy given on each of five consecutive days. FDR was associated with an increase in the uptake of decanol, and therefore a decrease in the effective resistance of the unstirred water layer. FDR had a variable effect on the uptake of glucose and leucine, with a decline in the value of the Michaelis constant (Km) and the passive permeability coefficient for glucose (Pd), whereas the Km for leucine was unchanged and the Pd for leucine was variably affected by FDR. The maximal transport rate (Jdm) for leucine progressively rose following FDR, whereas the Jdm for glucose initially rose, then fell. The uptake of galactose and medium chain-length fatty acids was unchanged by FDR, whereas the jejunal uptake of myristic acid rose, and the uptake of cholic acid declined, then returned to normal. FDR was associated with greater body weight gain and jejunal and ileal weight. The changes in nutrient uptake following FDR differed from the absorption changes occurring after a single dose of radiation. Thus, fractionated doses of abdominal radiation produce complex changes in the intestinal uptake of actively and passively transported nutrients, and these variable changes are influenced by the time following radiation exposure and by the solute studied.
- OSTI ID:
- 5001111
- Journal Information:
- Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 6; ISSN IOBPD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Saturated fatty acid diet prevents radiation-associated decline in intestinal uptake
Effect of external abdominal irradiation on the dimensions and characteristics of the barriers to passive transport in the rat intestine
Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABDOMEN
ABSORPTION
ALCOHOLS
ALDEHYDES
AMINO ACIDS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
BODY AREAS
CARBOHYDRATES
CARBOXYLIC ACIDS
DECANOLS
DIGESTIVE SYSTEM
DISACCHARIDES
FRACTIONATED IRRADIATION
GASTROINTESTINAL TRACT
GLUCOSE
HEXOSES
HORMONES
HYDROXY COMPOUNDS
IN VITRO
INSULIN
INTESTINAL ABSORPTION
INTESTINES
IRRADIATION
LACTOSE
LEUCINE
MAMMALS
MEDICINE
MONOSACCHARIDES
NUCLEAR MEDICINE
NUTRIENTS
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
RADIATION EFFECTS
RADIOLOGY
RADIOTHERAPY
RATS
RODENTS
SACCHARIDES
SIDE EFFECTS
SMALL INTESTINE
THERAPY
UPTAKE
VERTEBRATES