[The use of arteriography in the pharmacological study of a vasodilator substance].

The administration of a vasodilator substance is followed by the development of a higher contrast gradient in a given film in comparison with a reference X-ray carried out in the same subject under comparable technical conditions. Comparative densitometric measurement of the contrast gradient in the two successive arteriographic series, one with and one without the injection, arterial or venous, of a vasodilator substance (Couramine-Rutine) represents a valuable method for the study in man of the action of the substance in a visceral territory. The present study was limited to the kedney (79 cases), ans the territory of the superior mesenteric (46 cases). The absence of any densitometric difference between the two renal series at too low doses of vasodilator substance leads to the supposition of the possibility of a threshold dose of pharmacological activity.