Stroke, Vol 10, 727-732, Copyright © 1979 by American Heart Association
NA Lusamvuku, R Sercombe, P Aubineau and J Seylaz
Simultaneous measurements were made of spike activity and perfusion
pressure (PA) in intact segments of rabbit middle cerebral artery in vitro.
The segments were mounted on a Teflon tube designed so that the perfusing
solution flowed in the annular space between the tube and the artery wall,
thus magnifying the PA changes occurring when the artery constricted or
dilated. A widened portion of the Teflon tube immobilized 1--2 mm of the
artery segment for electrical recording with fine glass microelectrodes.
Spontaneous spike activity (extra- and intracellular) was regularly
observed. When a steady PA and spike discharge was obtained, tests were
performed by substituting for the normal perfusion liquid, solutions
containing 5 microgram/ml norepinephrine, 5 microgram/ml angiotensin II or
7.5 microgram/ml isoproterenol. Norepinephrine and angiotensin each
increased spike frequency (+ 293 and + 126%) and PA (+ 6.6 and + 7.9 mm Hg)
whereas isoproterenol decreased spike frequency (-89%) and PA (-22.9 mm
Hg). These results a) confirm the presence of receptors to these agents in
pial arteries, and b) demonstrate a high degree of correlation between
membrane electrical events and mechanical activity of these
spontaneously-active myovascular cells.
ARTICLES
Correlated electrical and mechanical responses of isolated rabbit pial arteries to some vasoactive drugs
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