Specificity of hepatic aldehyde dehydrogenase inhibition by calcium carbimide (calcium cyanamide) in the rat.

Acute, oral administration of 7.0 mg/kg calcium carbimide (calcium cyanamide) to rats, 2 h before sacrifice, produced complete inhibition of hepatic, low-Km (less than 1 microM acetaldehyde) mitochondrial and cytosolic aldehyde dehydrogenase enzymes and significantly inhibited high-Km (approximately 1 mM acetaldehyde) mitochondrial, cytosolic, and microsomal aldehyde dehydrogenase isozymes. Calcium carbimide had no effect on several other hepatic enzyme activities including mitochondrial glutamate dehydrogenase and monoamine oxidase, cytosolic alcohol dehydrogenase, microsomal NADPH-cytochrome c reductase, benzo[a]pyrene hydroxylase and aminopyrine N-demethylase activities, and microsomal cytochrome P-450 content. It is concluded that calcium carbimide is a more specific inhibitor of hepatic aldehyde dehydrogenase enzymes than disulfiram.