Journal article
Effects of Local Reduction in Pressure on Distensibility and Composition of Cerebral Arterioles
Circulation research, Vol.68(2), pp.338-351
02/1991
DOI: 10.1161/01.RES.68.2.338
PMID: 1991342
Abstract
This study examined effects of local reductions in mean and pulse pressures on cerebral arterioles in normotensive Wistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). WKY and SHRSP underwent clipping of one carotid artery at 1 month of age. At 10–12 months of age, mechanics of pial arterioles were examined in vivo in anesthetized rats. Bilateral craniotomies were performed to expose pial arterioles in the sham and clipped cerebral hemispheres. Stress-strain relations were calculated from measurements of pial arteriolar pressure (servo null), diameter, and cross-sectional area of the arteriolar wall. Point counting stereology was used to quantitate individual components in the arteriolar wall. Before deactivation of smooth muscle with EDTA, mean (Pm) and pulse (Pp) pressures were significantly less (p<0.05) in clipped than in sham arterioles in WKY (Pm, 63±2 versus 73±2 mm Hg; Pp, 23±3 versus 30±3 mm Hg) and SHRSP (Pm, 94±4 versus 110±4 mm Hg; Pp, 27±2 versus 38±3 mm Hg). Cross-sectional area of the arteriolar wall was less (p<0.05) in clipped than in sham arterioles in both groups of rats (1,403±125 versus 1,683±125 μm in WKY; 1,436±72 versus 1,926±134 μm in SHRSP). There was a correlation between cross-sectional area of the vessel wall and pulse pressure (r=0.66), but not mean pressure (r=0.09). During maximal dilatation with EDTA, the stress-strain curve was shifted to the left in clipped arterioles of SHRSP, but not of WKY, which indicates that carotid clipping in SHRSP reduces passive distensibility of cerebral arterioles. The proportion of distensible components in the vessel wall (smooth muscle, elastin, and endothelium) was reduced in clipped arterioles in SHRSP, but not in WKY. These findings suggest that 1) vascular hypertrophy of cerebral arterioles is related more closely to pulse pressure than to mean pressure, and 2) reduction of pial arteriolar pressure completely prevents cerebral vascular hypertrophy and attenuates increases in passive distensibility of cerebral arterioles in SHRSP. (Circulation Research 1991;68:338–351)
Details
- Title: Subtitle
- Effects of Local Reduction in Pressure on Distensibility and Composition of Cerebral Arterioles
- Creators
- Gary Baumbach - From the University of Iowa College of Medicine, Departments of Pathology and Internal Medicine, Cardiovascular Center, and the VA Medical Center, Iowa City, IowaJay SiemsDonald Heistad
- Resource Type
- Journal article
- Publication Details
- Circulation research, Vol.68(2), pp.338-351
- Publisher
- American Heart Association, Inc
- DOI
- 10.1161/01.RES.68.2.338
- PMID
- 1991342
- ISSN
- 0009-7330
- eISSN
- 1524-4571
- Language
- English
- Date published
- 02/1991
- Academic Unit
- Pathology; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Neuroscience and Pharmacology; Internal Medicine
- Record Identifier
- 9984040534502771
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