Adrenolytics substances

Spector and Willoughby - have pointed out that the vascular changes in the acute inflammatory reaction may be due to the destruction of local vasoconstrictor substances such as adrenaline. Evidence in favour of this mechanism includes the observation that increased capillary permeability after thermal injury is suppressed by iproniazid and other monoamine oxidase inhibitors. Such inhibitors are known to inhibit the conversion of adrenaline, noradrenaline, 5-hydroxytryptamine and other amines to inactive metabolites. The authors provide evidence that the action of the monoamine oxidase inhibitors on capillary permeability is dependent on their anti-enzymic activity and not on some other unrelated property. Nevertheless, the evidence remains indirect an attempt to detect pressor amines in the plasma of burned animals was unsuccessful. The potentiating effect of bretylium and the antagonistic action of an adrenolytic substance, dibenamine, on the action of iproniazid suggest that it is local depots of adrenaline rather than noradrenaline or 5-hydroxytryptamine which are involved. Independent support for this suggested role of catecholamines... 

As mentioned previously (page 64), Spector and Willoughby have suggested that some of the vascular phenomena occurring in tissue injury may be the result of the local destruction of adrenaline-like vasoconstrictor compounds. They measured increased capillary permeability in rats subjected to thermal injury and turpentine-induced pleurisy. The subcutaneous administration of five monoamine oxidase inhibitors, including iproniazid, markedly inhibits both types of inflammation. Iproniazid inhibition can be completely antagonized by the intravenous injection of the adrenolytic substance, dibenamine, but not by adrenalectomy. A subcutaneous dose of... 

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