A NEW CANNULA-INSERTING METHOD FOR MEASURING VASCULAR RESPONSIVENESS SEPARATE INTRALUMINAL AND EXTRALUMINAL PERFUSION OF CANINE BASILAR ARTERY

We modified the cannula-inserting method to examine the difference in response of vessels to intraluminal or extraluminal application of vasoactive substances. A polyethylene roof was designed to cover the isolated canine basilar artery so that an extraluminal superfusion stream could pass over an artery that simultaneously received an intraluminal perfusion. An extraluminal administration of KCl produced a monophasic transient vasoconstriction, but intraluminal KCl produced relatively small tonic constriction even at high concentrations. Serotonin-induced vasoconstrictions were significantly larger with intraluminal administration than with extraluminal. Prostaglandin F2alpha-induced vasoconstriction exhibited no significant difference between the administration routes. Endothelin caused a long-lasting constriction, which was slightly larger in extra- than intraluminal administration. Our modified cannula-inserting technique provides a new method to examine the different effects produced by intraluminal and extraluminal application of drugs.