Mechanical properties of rat middle cerebral arteries with and without myogenic tone
Autor: | Naomi C. Chesler, Lisa Vitullo, Rebecca J. Coulson, Marilyn J. Cipolla |
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Rok vydání: | 2004 |
Předmět: |
Male
medicine.medical_specialty Validation study Middle Cerebral Artery Cerebral arteries Biomedical Engineering Blood Pressure In Vitro Techniques Muscle Smooth Vascular Smooth muscle Wall stiffness Physiology (medical) Internal medicine medicine Inner diameter Animals Computer Simulation Elasticity (economics) Rats Wistar Chemistry Models Cardiovascular Elasticity Rats Muscle Tonus Cardiology Wall thickness Myogenic tone Muscle Contraction |
Zdroj: | Journal of biomechanical engineering. 126(1) |
ISSN: | 0148-0731 |
Popis: | The inner diameter and wall thickness of rat middle cerebral arteries (MCAs) were measured in vitro in both a pressure-induced, myogenically-active state and a drug-induced, passive state to quantify active and passive mechanical behavior. Elasticity parameters from the literature (stiffness derived from an exponential pressure-diameter relationship, beta, and elasticity in response to an increment in pressure, Einc-p) and a novel elasticity parameter in response to smooth muscle cell (SMC) activation, Einc-a, were calculated. beta for all passive MCAs was 9.11 +/- 1.07 but could not be calculated for active vessels. The incremental stiffness increased significantly with pressure in passive vessels; Einc-p (10(6) dynes/cm2) increased from 5.6 +/- 0.5 at 75 mmHg to 14.7 +/- 2.4 at 125 mmHg, (p < 0.05). In active vessels, Einc-p (10(6) dynes/cm2) remained relatively constant (5.5 +/- 2.4 at 75 mmHg and 6.2 +/- 1.0 at 125 mmHg). Einc-a (10(6) dynes/cm2) increased significantly with pressure (from 15.1 +/- 2.3 at 75 mmHg to 49.4 +/- 12.6 at 125 mmHg, p < 0.001), indicating a greater contribution of SMC activity to vessel wall stiffness at higher pressures. |
Databáze: | OpenAIRE |
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