aqueous leaf extract of clusia coclensis was applied at a dose of 40 mg/kg intravenously to isolated posterior extremities of six normotensive sprague-dawley rats and six spontaneously hipertensive rats anaesthetized with sodium nembutal. the perfusion was done in the abdominal artery using as carrier krebs bicarbonate ringer at 37 °c and keeping constant perfusion pressures of 100 mmhg in normotensive rats and 150 mmhg in hipertensive ratas. the venous return was measured in the inferior vena cava. the extract induced a significant reduction of the venous return begining 2 min after application, in both rat types. this may reflect a peripheral vasoconstriction that, in whole organism,would have an hipertensive effect. therefore, the mechanism of the alledgedly systemic hipotensive effect of the aqueous extract of clusia coclensis leafs resides probably at a central level, probably acting by a reduction of the contractibility of the myocardium.