2-Chloroacetaldehyde: a metabolite of cyclophosphamide in the rat

Chloroacetaldehyde has been shown to be a urinary metabolite of cyclophosphamide in the rat. It was identified in the urine of rats given a mixture of [ring C-4, 14C]-cyclophosphamide and [chloroethyl-3H]-cyclophosphamide as its 2,4-dinitrophenyl-hydrazone derivative by its 3H label and by its co-chromatography with chemically synthesised chloroacetaldehyde. The reaction of chloroacetaldehyde with another urinary metabolite of cyclophosphamide is discussed and a nornitrogen mustard adduct postulated. The toxicity of chloroacetaldehyde is also discussed particularly in relation to the urinary bladder.

2-Chloroacetaldehyde, a metabolite of cyclophosphamide in the rat

Following simultaneous i.v. administration of a mixture of [4-14C]cyclophosphamide (14C-CP) and [side-chain 3H]CP to rats, a metabolite containing predominantly 3H radioactivity was excreted in the urine. The 3H-labelled urinary metabolite was identified as 2-chloroacetaldehyde. Chloro[3H]acetaldehyde accounted for approx. 3.8% of urinary 3H radioactivity. The importance of chloroacetaldehyde as a toxic metabolite of CP is discussed, particularly in relation to haemorrhagic bladder disease.

Decreased plasma half-life of cyclophosphamide during repeated high-dose administration

Cyclophosphamide was given as IV doses of 50 mg/kg/day on each of four successive days as treatment for ovarian and lung cancer. Blood samples were taken at regular intervals and analysed for cyclophosphamide by gas liquid chromatography. The plasma half-lives (t 1/2) and volumes of distribution (V D) were calculated for each of the treatment days; t 1/2 was found to decrease with subsequent doses whereas V D was not significantly changed.

Comparison of administrators and direct service workers in agencies dealing with the elderly

This article presents comparative information, gained from mailed questionnaires, on the attitudes, knowledge, and perceptions of clients' needs held by 62 administrators and 57 direct-service personnel working with the aged. Administrators and direct-service workers were remarkably similar on each of these dimensions. Both groups demonstrated positive attitudes toward the aged and a deficit of certain types of factual knowledge about aging. Education was positively related to factual knowledge and favorable attitudes toward the elderly.

Metabolism and excretion of the liver-protective agent (+)-catechin in experimental hepatitis

1. Following oral administration of [U-14C](+)-catechin to rats with galactosamine-hepatitis, the biliary and faecal elimination of (+)-catechin metabolites was decreased compared with that in normal animals, Renal excretion of (+)-catechin metabolites was enhanced in galactosamine-hepatitis. 2. Although the biliary metabolites were present in similar proportions in galactosamine-hepatitis animals and controls, the major urinary metabolite, 3'-O-methyl (+)-catechin sulphate, was markedly decreased whereas 3'-O-methyl(+)-catechin glucuronide was increased by over 100%. 3. The total overall excretion of 3'-O-methyl (+)-catechin conjugates in rats with galactosamine-hepatitis was similar to that in normal animals indicating that catechol-O-methyltransferase activity is not significantly depressed in galactosamine-hepatitis. 4. Clearance of radioactivity from the blood following i.v. administration of [U-14C]-(+)-catechin was prolonged in galactosamine-hepatitis. 5. Liver perfusion experiments demonstrated depressed glucuronylation of (+)-catechin metabolites in galactosamine-hepatitis, whereas in liver homogenates synthesis of glucuronide conjugates of (+)-catechin metabolites was enhanced. 6. Lung slices were able to metabolize (+)-catechin and the lung is proposed as an extrahepatic site of (+)-catechin metabolism of increased importance in galactosamine-hepatitis. 7. The effects of galactosamine-hepatitis upon the structure of the hepatocyte plasma membrane are discussed in relation to decreased biliary excretion and glucuronylation.

Identification of the major biliary metabolite of (+)-catechin in the rat

1. Following oral administration of [U-14C]-(+)-catechin to the rat, the major biliary metabolite was shown to be the glucuronide of 3'-O-methyl-(+) catechin by chromatography and mass spectrometry. 2. [methyl-14C]-O-Methyl-(+)-catechin was formed by incubation of (+)-catechin with S-adenosyl-L-[methyl-14C]methionine in vitro in both liver homogenates and in the presence of purified catechol-O-methyl transferase. 3. Alkaline micro-fusion techniques have been used to determine the position of the O-methyl substituent in the B-ring of the isolated O-methyl-(+)-catechin glucuronide.