Inhibition of glucosamine synthesis by salicylates, hydrocortisone and two non-ulcerogenic drugs.

The in vitro inhibition of the glucosamine synthetase activity of rat gastric mucosal homogenates by sodium salicylate and phenylbutazone has been previously reported and has been adduced as a possible mechanism for the ulcerogenic effect of these drugs. This inhibition has been confirmed in human gastric and colonic mucosal homogenates and it is also shown by acetylsalicylic acid and by hydrocortisone hemisuccinate. However, paracetamol and gentamicin, neither of which is known to be ulcerogenic, also inhibited the enzyme to a similar degree to the ulcergenic drugs. This refutes glucosamine synthetase inhibition as the mechanism of the ulcerogenic action of anti-inflammatory drugs.