Myogenic reactivity and resistance distribution in the coronary arterial tree: a model study.
نویسندگان
چکیده
The objectives of this study were to evaluate the myogenic behavior of blood vessels and their interaction within the coronary arterial tree and to evaluate the possible role of the myogenic response in autoregulation. The model consists of 10 compartments in series, each representing a class of vessel sizes. Diameter and resistance in each class are determined by their value at full dilation (d(p,) R(p)) and by the myogenic response. Three distributions of R(p) and three distributions of myogenic strength, M(i) (slope of pressure-diameter curve, range -0.05 to -0.4%/mmHg) were evaluated (9 cases). It was found that larger vessels attenuate the myogenic activity of smaller vessels and that myogenic responsiveness is sufficient to achieve autoregulation. When M(i) has a maximum in vessels of 84 microm, the maximum effect of perfusion pressure on active diameter occurs in vessels between 123 and 181 microm, depending on the distribution of R(p). Distribution of resistance and control mechanisms in the coronary arterial tree are important for interpretation of individual vessel responses as observed in vivo.
منابع مشابه
Balance between myogenic, flow-dependent, and metabolic flow control in coronary arterial tree: a model study.
Myogenic response, flow-dependent dilation, and direct metabolic control are important mechanisms controlling coronary flow. A model was developed to study how these control mechanisms interact at different locations in the arteriolar tree and to evaluate their contribution to autoregulatory and metabolic flow control. The model consists of 10 resistance compartments in series, each representin...
متن کاملAn advection-diffusion multi-layer porous model for stent drug delivery in coronary arteries
Arterial drug concentration distribution determines local toxicity. The safety issues dealt with Drug-Eluting Stents (DESs) reveal the needs for investigation about the effective factors contributing to fluctuations in arterial drug uptake. The current study focused on the importance of hypertension as an important and controversial risk factor among researchers on the efficacy of Heparin-Eluti...
متن کاملEndothelin and nitric oxide mediate reduced myogenic reactivity of small renal arteries from pregnant rats.
We tested the hypothesis that endothelin acting through the endothelial ET(B) receptor subtype and the nitric oxide (NO) pathway accounts for reduced myogenic reactivity of the renal resistance vasculature during pregnancy. Small renal arteries (100-200 microm) were isolated from virgin and midterm pregnant rats when gestational renal hyperfiltration and vasodilation are maximal in this species...
متن کاملComparing the Results of Logistic Regression Model and Classification and Regression Tree Analysis in Determining Prognostic Factors for Coronary Artery Disease in Mashhad, Iran
Background and purpose: Understanding of the risk factors for cardiovascular artery disease, which is the leading cause of death worldwide, can lead to essential changes in its etiology, prevalence, and treatment. The aim of this study was to compare the results of logistic regression model and Classification and Regression Tree Analysis (CART) in determining the prognostic factors for coronary...
متن کاملMyogenic tone, reactivity, and forced dilatation: a three-phase model of in vitro arterial myogenic behavior.
Myogenic behavior, prevalent in resistance arteries and arterioles, involves arterial constriction in response to intravascular pressure. This process is often studied in vitro by using cannulated, pressurized arterial segments from different regional circulations. We propose a comprehensive model for myogenicity that consists of three interrelated but dissociable phases: 1) the initial develop...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- American journal of physiology. Heart and circulatory physiology
دوره 278 5 شماره
صفحات -
تاریخ انتشار 2000