The action of sodium salicylate and aspirin on some kallikrein systems

Salicylate and enzymes

Salicylate inhibits the activities of a number of cellular enzymes and in some instances the mechanisms of inhibition have been established (Smith, 1968a). Reported inhibitory actions of the salicylate ion on important enzyme systems in vitro are now reviewed and assessed in relation to the known clinical and toxic effects of the drug.

The action of glucosulphone [N,N'-di (glucose sodium sulphonate) of 4,4'-diaminodiphenyl sulphone] on pancreatic kallikrein

1. The effects of sulphone have been studied on kinin production in dog plasma and on capillary permeability in the skin of rabbits.2. Dog plasma was used as a substrate for pancreatic kallikrein in vitro and the addition of sulphone caused an inhibition of kinin production, which was dependent on the concentration of the drug.3. The increased vascular permeability produced in vivo by intradermal injections of kallikrein was partially inhibited by sulphone injected intravenously. The same doses of sulphone also inhibited the increase in permeability produced by bradykinin and histamine in the skin of rabbits.

Kinins and anti-inflammatory steroids

1. This investigation was designed to re-examine the possibility that anti-inflammatory steroids interfere with the kinin-forming system.2. We conclude that the anti-inflammatory action of corticosteroids cannot be explained by the inhibition of kinin formation. This view is based on the following findings.3. Neither hydrocortisone nor prednisolone nor dexamethasone inhibited the activation or activity of intrinsic plasma kinin forming enzymes resulting from dilution, incubation with kininase inhibitors, or exposure to glass, monosodium urate microcrystals or to precipitated complexes of rheumatoid factor and aggregated human gamma-globulin.4. Hydrocortisone did not inhibit the action of the active kinin-forming enzymes, human salivary or urinary kallikrein, or plasmin on purified kininogen.5. Hydrocortisone, prednisolone and dexamethasone did not inhibit the hydrolysis of benzoyl-arginine-ethyl ester by human plasmin, plasma kallikrein or hog pancreatic kallikrein.6. Kinin formation occurred normally in plasma taken from two patients receiving betamethasone and one receiving prednisone.