Chromatographic resolution of amino acid adducts of aliphatic halides.

Numerous xenobiotics are known to be bioactivated and to covalently and to proteins, but the resulting amino acid adducts (AAAs) are unknown. In this study the AAAs of twelve 14C-labeled aliphatic halides were examined after formation in an in vitro microsomal system. After exhaustive solvent extraction of the precipitated microsomal protein, the AAAs were isolated by Pronase digestion, followed by filtration through a 500 mol. wt. exclusion membrane. The liberated AAAs were applied to a constant flow DC-4A cation exchange column, resolved by stepwise buffer elution, collected and counted for radioactivity. Column recovery for applied radioactivity was 100 +/- 4%. Generally, 1-4 different AAAs (defined by eluting radioactivity) were resolved, with each organohalogen displaying a characteristic elution profile. Methyl iodide, trichloroethylene and 1,2-dichloroethylene had a single major AAA while bromotrichloromethane, 1,2-dibromoethane, 1,1,1-trichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane, 2-bromo-2-chloro-1,1,1-trifluoroethane, chloroform and carbon tetrachloride had up to 4 AAAs or more, indicating combinations of binding site(s) and reactive intermediate(s). The single AAA formed following incubation of methyl iodide with the microsomes was identified as S-methylcysteine. Thus, this method appears capable of resolving binding sites and is the initial isolation step for identifying specific adducts to proteins.

Urine output and fluid therapy during anaesthesia and surgery.

To try to determine whether fluid therapy during surgery should be on a large or a small scale 23 patients and six control subjects were studied. The control subjects were fasted and transfused with 2 litres of Ringer-lactate solution in one hour, the volume of urine output being measured at intervals for four hours. The patients were transfused similarly under varying conditions of anaesthesia and surgery. The characteristic urine output during abdominal hysterectomy followed a low, irregular pattern, and this occurred whether or not substantial amounts of fluid were transfused. In two patients anaesthesia and minimal trauma were associated with oliguria. An established diuresis was altered by anaesthesia and inhibited by surgery. These results indicate that excess Ringer-lactate solution administered during surgery may not be excreted and that overtransfusion could easily occur.