Acute nicotinamide deficiency in the pig induced by 6-aminonicotinamide.

Pigs given intraperitoneal injections of 6-aminonicotinamide developed a syndrome similar to a natural disease found in Queensland. Focal lesions, involving mainly destruction of glial cells, developed in the intermediate grey matter of the cervical and lumbar enlargement of the spinal cord. There was widespread vacuolation of spinal cord white matter. The glial cell loss was repaired. We suggest that natural acute nicotinamide deficiency can occur if a threshold dose of an antimetabolite of nicotinamide is absorbed over a short period of time.