The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Alan J Bank - One of the best experts on this subject based on the ideXlab platform.

  • in vivo human brachial artery elastic mechanics effects of Smooth Muscle Relaxation
    Circulation, 1999
    Co-Authors: Alan J Bank, Daniel R Kaiser, Scott Rajala, Anthony Cheng
    Abstract:

    Background—–The effects of Smooth Muscle Relaxation on arterial wall mechanics are controversial. We used a new, in vivo, noninvasive technique to measure brachial artery wall mechanics under baseline conditions and following Smooth Muscle Relaxation with nitroglycerin (NTG). Methods and Results—Eight healthy, normal subjects (6 male, 2 female; age 30±3.1 years) participated in the study. The nondominant brachial artery was imaged through a water-filled blood pressure cuff using an external ultrasound wall-tracking system at baseline and following 0.4 mg sublingual NTG. Simultaneous radial artery pressure waveforms were recorded by tonometry. Transmural pressure (TP) was reduced by increasing water pressure in the cuff. Brachial artery area, unstressed area, compliance, stress, strain, incremental elastic modulus (Einc), and pulse wave velocity (PWV) were measured over a TP range from 0 to 100 mm Hg. Baseline area versus TP curves generated 30 minutes apart were not significantly different. NTG significan...

  • Smooth Muscle Relaxation effects on arterial compliance distensibility elastic modulus and pulse wave velocity
    Hypertension, 1998
    Co-Authors: Alan J Bank, Daniel R Kaiser
    Abstract:

    Abstract —Compliance, distensibility, incremental elastic modulus (E inc ), and pulse wave velocity are all terms used to describe the mechanical properties of arteries. Previous studies assessing the effects of Smooth Muscle Relaxation on each of these parameters have produced conflicting results. Our laboratory has previously demonstrated that intrabrachial infusion of nitroglycerin in normal human subjects results in a large increase in brachial artery compliance without changing arterial wall stiffness as measured by E inc . In the present study, the relationships among compliance, distensibility, E inc , and pulse wave velocity under different levels of vascular tone are shown using data acquired by intravascular ultrasound as well as theoretical curves. We demonstrate that the effects of Smooth Muscle Relaxation can be depicted as 2 separate steps: (1) a rightward shift to a new theoretical curve describing the relationship between 2 of the above elastic parameters that is solely due to changes in vessel geometry and (2) a shift along the new curve that is dependent on changes in wall stiffness.

  • direct effects of Smooth Muscle Relaxation and contraction on in vivo human brachial artery elastic properties
    Circulation Research, 1995
    Co-Authors: Alan J Bank, Robert F Wilson, Spencer H Kubo, J Holte, Thomas J Dresing, Hongyu Wang
    Abstract:

    Abstract The direct effect of Smooth Muscle Relaxation on arterial elastic properties is controversial. Studies in animals show both a decrease and an increase in elastic modulus. In human subjects, the contribution of Smooth Muscle to arterial elastic mechanics has been limited by difficulty in separating the direct effects of a vasodilator drug on the arterial wall from the indirect effects due to reduced blood pressure. The purpose of the present study was to assess the direct contribution of vascular Smooth Muscle to brachial artery elastic mechanics in normal human subjects in vivo. We measured brachial artery compliance and incremental elastic modulus (Einc) in eight normal subjects (age, 22 to 51 years) by using intravascular ultrasound. A 3.5F 30-MHz intravascular ultrasound catheter was placed through a sheath into the brachial artery, and intra-arterial pressure, cross-sectional area, and wall thickness were measured simultaneously under baseline conditions and after the administration of intra-...

Anthony Cheng - One of the best experts on this subject based on the ideXlab platform.

  • in vivo human brachial artery elastic mechanics effects of Smooth Muscle Relaxation
    Circulation, 1999
    Co-Authors: Alan J Bank, Daniel R Kaiser, Scott Rajala, Anthony Cheng
    Abstract:

    Background—–The effects of Smooth Muscle Relaxation on arterial wall mechanics are controversial. We used a new, in vivo, noninvasive technique to measure brachial artery wall mechanics under baseline conditions and following Smooth Muscle Relaxation with nitroglycerin (NTG). Methods and Results—Eight healthy, normal subjects (6 male, 2 female; age 30±3.1 years) participated in the study. The nondominant brachial artery was imaged through a water-filled blood pressure cuff using an external ultrasound wall-tracking system at baseline and following 0.4 mg sublingual NTG. Simultaneous radial artery pressure waveforms were recorded by tonometry. Transmural pressure (TP) was reduced by increasing water pressure in the cuff. Brachial artery area, unstressed area, compliance, stress, strain, incremental elastic modulus (Einc), and pulse wave velocity (PWV) were measured over a TP range from 0 to 100 mm Hg. Baseline area versus TP curves generated 30 minutes apart were not significantly different. NTG significan...

Hongyu Wang - One of the best experts on this subject based on the ideXlab platform.

  • direct effects of Smooth Muscle Relaxation and contraction on in vivo human brachial artery elastic properties
    Circulation Research, 1995
    Co-Authors: Alan J Bank, Robert F Wilson, Spencer H Kubo, J Holte, Thomas J Dresing, Hongyu Wang
    Abstract:

    Abstract The direct effect of Smooth Muscle Relaxation on arterial elastic properties is controversial. Studies in animals show both a decrease and an increase in elastic modulus. In human subjects, the contribution of Smooth Muscle to arterial elastic mechanics has been limited by difficulty in separating the direct effects of a vasodilator drug on the arterial wall from the indirect effects due to reduced blood pressure. The purpose of the present study was to assess the direct contribution of vascular Smooth Muscle to brachial artery elastic mechanics in normal human subjects in vivo. We measured brachial artery compliance and incremental elastic modulus (Einc) in eight normal subjects (age, 22 to 51 years) by using intravascular ultrasound. A 3.5F 30-MHz intravascular ultrasound catheter was placed through a sheath into the brachial artery, and intra-arterial pressure, cross-sectional area, and wall thickness were measured simultaneously under baseline conditions and after the administration of intra-...

Daniel R Kaiser - One of the best experts on this subject based on the ideXlab platform.

  • in vivo human brachial artery elastic mechanics effects of Smooth Muscle Relaxation
    Circulation, 1999
    Co-Authors: Alan J Bank, Daniel R Kaiser, Scott Rajala, Anthony Cheng
    Abstract:

    Background—–The effects of Smooth Muscle Relaxation on arterial wall mechanics are controversial. We used a new, in vivo, noninvasive technique to measure brachial artery wall mechanics under baseline conditions and following Smooth Muscle Relaxation with nitroglycerin (NTG). Methods and Results—Eight healthy, normal subjects (6 male, 2 female; age 30±3.1 years) participated in the study. The nondominant brachial artery was imaged through a water-filled blood pressure cuff using an external ultrasound wall-tracking system at baseline and following 0.4 mg sublingual NTG. Simultaneous radial artery pressure waveforms were recorded by tonometry. Transmural pressure (TP) was reduced by increasing water pressure in the cuff. Brachial artery area, unstressed area, compliance, stress, strain, incremental elastic modulus (Einc), and pulse wave velocity (PWV) were measured over a TP range from 0 to 100 mm Hg. Baseline area versus TP curves generated 30 minutes apart were not significantly different. NTG significan...

  • Smooth Muscle Relaxation effects on arterial compliance distensibility elastic modulus and pulse wave velocity
    Hypertension, 1998
    Co-Authors: Alan J Bank, Daniel R Kaiser
    Abstract:

    Abstract —Compliance, distensibility, incremental elastic modulus (E inc ), and pulse wave velocity are all terms used to describe the mechanical properties of arteries. Previous studies assessing the effects of Smooth Muscle Relaxation on each of these parameters have produced conflicting results. Our laboratory has previously demonstrated that intrabrachial infusion of nitroglycerin in normal human subjects results in a large increase in brachial artery compliance without changing arterial wall stiffness as measured by E inc . In the present study, the relationships among compliance, distensibility, E inc , and pulse wave velocity under different levels of vascular tone are shown using data acquired by intravascular ultrasound as well as theoretical curves. We demonstrate that the effects of Smooth Muscle Relaxation can be depicted as 2 separate steps: (1) a rightward shift to a new theoretical curve describing the relationship between 2 of the above elastic parameters that is solely due to changes in vessel geometry and (2) a shift along the new curve that is dependent on changes in wall stiffness.

José Henrique Leal-cardoso - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of terpinen-4-ol effects on vascular Smooth Muscle Relaxation.
    Life Sciences, 2014
    Co-Authors: Rebeca Peres Moreno Maia-joca, Humberto Cavalcante Joca, Francisca Jéssica Penha Ribeiro, Renata Vieira Do Nascimento, Kerly Shamyra Da Silva-alves, Jader S. Cruz, Andrelina Noronha Coelho-de-souza, José Henrique Leal-cardoso
    Abstract:

    Abstract Aims This study investigated the mechanisms underlying the vascular effects of terpinen-4-ol in isolated rat aortic ring preparations. Main methods The thoracic aortae of healthy rats were submitted to isometric tension recording. Membrane resting potential and input membrane resistance were measured by conventional microelectrode technique. Key findings Terpinen-4-ol reversibly relaxed endothelium-containing preparations pre-contracted with high K+ and phenylephrine with IC50 values of 421.43 μM and 802.50 μM, respectively. These effects were significantly reduced by vascular endothelium removal. In Ca2 +-free and high K+ (80 mM) medium, the contractions produced by Ba2 + were reduced by terpinen-4-ol (100–1000 μM) in a concentration-dependent manner. In aortic rings maintained under Ca2 +-free conditions, terpinen-4-ol significantly reduced the contractions induced by either phenylephrine (1 μM) or phorbol 12,13-dibutyrate (1 μM). Terpinen-4-ol (10–1000 μM) also relaxed the contractions evoked by BAYK-8644 (3 μM) with an IC50 of 454.23 μM. Neither membrane resting potential nor input resistance of Smooth Muscle cells was altered by terpinen-4-ol exposure. Significance The present results suggest that terpinen-4-ol induced vascular Smooth Muscle Relaxation that was preferentially due to the inhibition of electromechanical pathways related to calcium influx through voltage-operated calcium channels.

  • Investigation of terpinen-4-ol effects on vascular Smooth Muscle Relaxation.
    Life sciences, 2014
    Co-Authors: Rebeca Peres Moreno Maia-joca, Humberto Cavalcante Joca, Francisca Jéssica Penha Ribeiro, Kerly Shamyra Da Silva-alves, Jader S. Cruz, Andrelina Noronha Coelho-de-souza, Renata Vieira Do Nascimento, José Henrique Leal-cardoso
    Abstract:

    This study investigated the mechanisms underlying the vascular effects of terpinen-4-ol in isolated rat aortic ring preparations. The thoracic aortae of healthy rats were submitted to isometric tension recording. Membrane resting potential and input membrane resistance were measured by conventional microelectrode technique. Terpinen-4-ol reversibly relaxed endothelium-containing preparations pre-contracted with high K(+) and phenylephrine with IC50 values of 421.43 μM and 802.50 μM, respectively. These effects were significantly reduced by vascular endothelium removal. In Ca(2+)-free and high K(+) (80 mM) medium, the contractions produced by Ba(2+) were reduced by terpinen-4-ol (100-1000 μM) in a concentration-dependent manner. In aortic rings maintained under Ca(2+)-free conditions, terpinen-4-ol significantly reduced the contractions induced by either phenylephrine (1 μM) or phorbol 12,13-dibutyrate (1 μM). Terpinen-4-ol (10-1000 μM) also relaxed the contractions evoked by BAYK-8644 (3 μM) with an IC50 of 454.23 μM. Neither membrane resting potential nor input resistance of Smooth Muscle cells was altered by terpinen-4-ol exposure. The present results suggest that terpinen-4-ol induced vascular Smooth Muscle Relaxation that was preferentially due to the inhibition of electromechanical pathways related to calcium influx through voltage-operated calcium channels. Copyright © 2014 Elsevier Inc. All rights reserved.