Test of venoconstriction in humans; an improved technic for quantitative evaluation of venous spasm
Del Bianco, P.L.; Sicuteri, F.
Bollettino della Societa Italiana di Biologia Sperimentale 51(14): 883-888
1975
ISSN/ISBN: 0037-8771 PMID: 1218108 Document Number: 85426
A venoconstrictor test is described, designed to record and measure venous spasm upon stimulating the venomotor receptors of man with 5-hydroxytryptamine, noradrenaline or adrenaline. The apparatus used is composed of an Ovlson needle (0.8 mm internal diameter), connected by a rigid Teflon tube to a syringe and a pressure transducer. The syringe injects physiological saline solution inside the tube at constant velocity by means of an electric perfusor. The pressure transduced is preamplified electromanometrically and recorded on paper. In series with the preamplifier is an integrating apparatus, which transcribes the integral of the pressure curve from the transducer. The Ovlson needle, inserted in a vein by means of the Teflon tube, transmits to the transducer the venous pressure and variations produced locally by pharmacological means. Minimal doses of vasoconstrictor produce a pressure curve suitable for the recording system. Pressure variations lie between 2-4 mm Hg. A more exact evaluation of venoconstrictive responses is obtained by measuring the surface of venoconstriction, which is the area inscribed between the base line and the curve of venoconstrictor pressure.