title: Low volume perfusion-superfusion system for measurement of transmitter release from blood vessels in vitro.
abstract: An in vitro technique has been developed for the simultaneous recording of vasoconstriction and transmitter release from small perfused blood vessels. To avoid excessive dilution of the released substances, 6-12-mg segments of rabbit ear arteries or rat tail arteries were mounted in 0.5-mL tissue chambers and perfused-superfused in a closed system. Drug administration and removal were performed by timer-controlled solenoid valves. Oscillation in the baseline generated by the roller pump was dampened by delivering Kreb's solution through a 4-mL buffer vial filled partly with air. Vasoconstriction was elicited by electrical stimulation and detected by pressure sensitive transducers. Transducer-generated electrical signals were amplified, digitalized, and recorded by a computerized system. Release of norepinephrine was measured after the tissue was preloaded with [3H]norepinephrine. This system allowed us to measure minimum vasoconstrictions of 1-2 mm Hg and [3H]norepinephrine efflux evoked by 4-8 electrical pulses. There was a good linear correlation (r = 0.98) between the contractile responses and tritiated norepinephrine release. Endogenous norepinephrine released by electrical stimulation into the perfusion media was determined by high-performance liquid chromatography (HPLC) in the low picogram range (80-100 pg). Our novel experimental setup permits computerized data acquisition and automated in vitro pharmacological experiments on isolated blood vessels.
authors.affiliation: Department of Pharmacology, College of Medicine, University of California, Irvine 92717.
authors.forename: D
authors.initials: D
authors.lastname: Budai
authors.forename: J N
authors.initials: JN
authors.lastname: Buchholz
authors.forename: S P
authors.initials: SP
authors.lastname: Duckles
mesh_terms: D000818:Animals; D001158:Arteries / Q000378:metabolism; D004423:Ear / Q000098:blood supply; D007260:Infusion Pumps; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010477:Perfusion / Q000295:instrumentation*; D011817:Rabbits; D051381:Rats; D013623:Tail / Q000098:blood supply; D014661:Vasoconstriction
chemical_list: D009638:Norepinephrine