Polyethylene glycol excretion

The contribution of reabsorbed biliary metabolites to urinary excretion is reflected in the differences in urinary excretion of label from bile duct cannulated rats and noncannulated rats. When a dose of 1 mg/kg hexachlorobutadiene in polyethylene glycol solution was given to bile duct cannulated male rats, the urine contained 11 % of the label after 72 hours in noncannulated rats given the same dose it contained 18% of the label (Payan et al. 1991). When a dose of 100 mg/kg was given, the urine of the cannulated rats contained 7% of the label and the urine of the noncannulated rats contained 9% after 72 hours. 

After the equilibration period, clearance periods of 20 min are used. Urine samples are collected and perfusate is obtained at midpoint of the clearance period for the evaluation of overall kidney function. For determination of glomerular filtration rate (GFR) and fluid transport, 3H-labelled polyethylene glycol is added to a modified Krebs-Henseleit bicarbonate buffer. Electrolytes are determined in urine by standard flame photometry. Fractional excretions of water, electrolytes and test compounds are calculated. 

To determine the amount of isotope required for an absorption study using fecal monitoring, the length of time of fecal collections must be considered. Polyethylene glycol (PEG) and radioisotopes were used for to determine complete intestinal transit time in the studies described in this paper. In one study PEG and radioisotopes were fed simultaneously and excretion patterns were similar for the two (1>9). Most individuals eliminate all PEG or unabsorbed radioisotopes within 12 days, but a few individuals have longer transit times. Therefore 12 days collection time can be used for calculations. The amount of mineral expected in the 12 day collection is used to determine the amount of isotope to feed for best analytical precision. A mineral such as copper cannot be fed at a level to meet ideal enrichment conditions without greatly exceeding... 

Brady CE 3rd, DiPalma JA, Morawski SG, Santa Ana CA, Fordtran JS. Urinary excretion of polyethylene glycol 3350 and sulfate after gut lavage with a polyethylene glycol electrolyte lavage solution. Gastroenterology 1986 90(6) 1914-18. 

Liquid polyethylene glycols are rapidly excreted in the urine, while the higher-molecular-weight members are mainly eliminated in the feces. 

Carpenter, C., Woodside, M., Kinkead, E., King, J., Sullivan, L., Response of dogs to repeated intravenous injection of polyethylene glycol 4000 with notes on excretion and sensitization, Toxicol. Appl. Pharmacol. 18, 35-40, 1971. 

Intestinal permeability may be measured following the administration of polyethylene glycol polymers (Walsh 2001), by the urinary excretion of orally administered sucrose as a marker of gastroduodenal damage and 51Cr-EDTA as markers of gastroduodenal and intestinal permeability (Yanez et al. 2003), or by other markers (Bjarnason, MacPherson, and Hollander 1995 Ford, Martin, and Houston 1995). 

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