title: Measurement of hydraulic conductivity in isolated arterioles of rat brain cortex.
abstract: We have developed a new method for quantification of arteriolar hydraulic conductivity (Lp) from isolated rat brain vessels. The volume flux of water per unit surface area across the arteriole wall (Jv/S) was assessed from measurements of silicon oil drop movement within an occluded vessel at two to three pressures (between 20 and 70 mmHg); the Lp was derived from the slope of the relationship between Jv/S and applied pressure. Lp was measured in isolated cerebral arterioles 1) at room temperature (22 degrees C) without spontaneous vessel tone (control Lp; n = 11), 2) at room temperature with 10(-4) M adenosine (n = 5), and 3) at 37 degrees C with vessels dilated submaximally with 10(-4) M adenosine (n = 6). Lp at 22 degrees C without adenosine was 13.2 +/- 4.2 x 10(-9) (+/- SE) cm.s-1.cmH2O-1 for all vessels studied. Lp values ranged from 1.2 to 44.1 x 10(-9) cm.s-1.cmH2O-1 with a median value that was 5.9 x 10(-9) cm.s-1.cmH2O-1. Lp increased significantly (on average, 2.6-fold) with adenosine at 37 degrees C but not with adenosine at 22 degrees C. Control Lp bore no relationship to either the development of spontaneous tone or the diameter response to pH change, two recognized indicators of vessel viability.
authors.affiliation: Department of Neurosurgery, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: H H
authors.initials: HH
authors.lastname: Dietrich
authors.forename: V H
authors.initials: VH
authors.lastname: Huxley
authors.forename: D R
authors.initials: DR
authors.lastname: Reichner
authors.forename: R G
authors.initials: RG
authors.lastname: Dacey
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001160:Arterioles; D001812:Blood-Brain Barrier; D002540:Cerebral Cortex / Q000098:blood supply; D002560:Cerebrovascular Circulation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008955:Models, Cardiovascular; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012827:Silicone Oils; D013696:Temperature
chemical_list: D012827:Silicone Oils; D000241:Adenosine