Aldehyde dehydrogenase inhibitors and voluntary ethanol drinking by rats.

Aldehyde dehydrogenase (ALDH) inhibitors, cyanamide (200 mg or 40 mg/kg food) and coprine (N5-(hydroxycyclopropyl)-L-glutamine, 500 mg/kg food), strongly suppressed, with similar time courses, the free-choice consumption of 10% v/v ethanol. The suppression occurred with both continual and alternate access to alcohol. The presence of the inhibitors (plus 4-methylpyrazole to prevent acetaldehyde accumulation) did not affect ethanol-induced (1.5 g/kg i.p.) motor impairment on the tilting plane, but the rats on alternate-day access, which consumed more alcohol on days of access, were significantly less impaired.