Some pharmacological properties of the venom of the scorpionfish Scorpaena guttata—II

Labile components of California scorpionfish venom produce marked respiratory and hemodynamic changes in cats, rabbits and dogs. The venom affects respiratory rate, causes bronchoconstriction and pulmonary edema; large doses cause respiratory arrest. The venom produces arterial hypotension within 15 sec, followed by a period of increased pressure. The hypotension represents a major distributive defect of blood volume in the peripheral circuit due to a defect in arterial resistance most likely due to the release of endogenous acetylcholine. This effect can be inhibited by pretreatment with atropine. Other prominent alterations include pulmonary artery hypertension, elevation of left ventricular end-diastolic pressure, portal venous hpertension, ECG changes, elevation of the packed cell volume and initial augmentation of systemic venous return. It is most likely that the venom acts through a combination of direct actions, neurogenic reflex mechanisms and effects induced by the liberation of autopharmacological substances.