IDENTIFICATION OF NORADRENALINE IN VENOM FROM THE FUNNEL-WEB SPIDER HOLOLENA-CURTA

Venom from the funnel-web spider Hololena curta was added to the Krebs -Henseleit solution bathing isolated ring preparations of rat thoracic aorta, suspended in water-jacketed organ baths, for the purpose of te nsion recordings. Hololena curta venom at dilutions of 1:100,000 to 1: 1000 caused a marked vasoconstriction, which was completely inhibited by the alpha(1) adrenoceptor antagonist prazosin (1 mu M). The vasocon striction appears to be due to the direct effects on alpha(1) adrenoce ptors of a venom constituent, which we have identified using HPLC/ECD as the catecholamine, noradrenaline.