scholarly journals Modeling of Cardiac Component of Subarachnoid Space Changes in Apnoea Resulting as a Function of Blood Pressure and Blood Flow Parameters - Two Mechanizm of Regulation

2017 ◽  
Author(s):  
Kamila Mazur ◽  
Renata Kalicka ◽  
Andrzej F. Frydrychowski ◽  
Pawel J. Winklewski
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Subarachnoid Space ◽  
Flow Parameters ◽  
Cardiac Component

scholarly journals sGC Activity and Regulation of Blood Flow in a Zebrafish Model System

2021 ◽  
Vol 12 ◽  
Author(s):  
Krishan K. Vishnolia ◽  
Aleksandar Rakovic ◽  
Celine Hoene ◽  
Karim Tarhbalouti ◽  
Zouhair Aherrahrou ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Model System ◽  
Linear Velocity ◽  
Chromosomal Locus ◽  
Zebrafish Model ◽  
Flow Parameters ◽  
Screening Experiments ◽  
Significant Difference ◽  
Underlying Mechanisms

Soluble guanylyl cyclase (sGC) protein is a heterodimer formed by two subunits encoded by GUCY1A1 and GUCY1B1 genes. The chromosomal locus 4q32.1 harbors both of these genes, which has been previously significantly associated with coronary artery disease, myocardial infarction, and high blood pressure. Blood pressure is influenced by both the environment and genetics and is complemented by several biological pathways. The underlying mechanisms associated with this locus and its genes still need to be investigated. In the current study, we aimed to establish the zebrafish as a model organism to investigate the mechanisms surrounding sGC activity and blood pressure. A zebrafish mutant gucy1a1 line was generated using the CRISPR-Cas9 system by inducing a 4-bp deletion frameshift mutation. This mutation resulted in a reduction of gucy1a1 expression in both heterozygote and homozygote zebrafish. Blood flow parameters (blood flow, arterial pulse, linear velocity, and vessel diameter) investigated in the gucy1a1 mutants showed a significant increase in blood flow and linear velocity, which was augmented in the homozygotes. No significant differences were observed for the blood flow parameters measured from larvae with individual morpholino downregulation of gucy1a1 and gucy1b1, but an increase in blood flow and linear velocity was observed after co-morpholino downregulation of both genes. In addition, the pharmacological sGC stimulator BAY41-2272 rescued the impaired cGMP production in the zebrafish gucy1a1± mutant larvae. Downregulation of cct7 gene did not show any significant difference on the blood flow parameters in both wild-type and gucy1a1± background larvae. In summary, we successfully established a zebrafish platform for investigating sGC-associated pathways and underlying mechanisms in depth. This model system will have further applications, including for potential drug screening experiments.

Modelling of subarachnoid space width changes in apnoea resulting as a function of blood flow parameters

2017 ◽  
Vol 113 ◽  
pp. 16-21 ◽  
Author(s):  
Renata Kalicka ◽  
Kamila Mazur ◽  
Jacek Wolf ◽  
Andrzej F. Frydrychowski ◽  
Krzysztof Narkiewicz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Subarachnoid Space ◽  
Flow Parameters ◽  
Space Width

scholarly journals Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 113
Author(s):  
Agnieszka Gruszecka ◽  
Magdalena K. Nuckowska ◽  
Monika Waskow ◽  
Jacek Kot ◽  
Pawel J. Winklewski ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Subarachnoid Space ◽  
Brain Hemispheres ◽  
New Findings ◽  
Inspiratory Resistance ◽  
Cardiac Component ◽  
Slow Breathing ◽  
Effective Phase ◽  
Space Width ◽  
The Brain

The precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on a group of 20 healthy volunteers (12 females and 8 males; BMI =22.1±3.2 kg/m2; age 25.3±7.9 years). We analysed the recorded signals with a wavelet transform. For the first time, a method based on dynamical Bayesian inference was used to detect the effective phase connectivity and the underlying coupling functions between the SAS and BP signals. There are several new findings. Slow breathing with or without resistance increases the strength of the coupling between the respiratory and cardiac components of both measured signals. We also observed increases in the strength of the coupling between the respiratory component of the BP and the cardiac component of the SAS and vice versa. Slow breathing synchronises the SAS oscillations, between the brain hemispheres. It also diminishes the similarity of the coupling between all analysed pairs of oscillators, while inspiratory resistance partially reverses this phenomenon. BP–SAS and SAS–BP interactions may reflect changes in the overall biomechanical characteristics of the brain.

Lutein Complex Supplementation Increases Ocular Blood Flow Biomarkers in Healthy Subjects

2019 ◽  
Vol 89 (1-2) ◽  
pp. 5-12
Author(s):  
Alon Harris ◽  
Brent Siesky ◽  
Amelia Huang ◽  
Thai Do ◽  
Sunu Mathew ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Diastolic Blood Pressure ◽  
Healthy Subjects ◽  
Ocular Blood Flow ◽  
Capillary Blood ◽  
Post Treatment ◽  
Capillary Blood Flow ◽  
Doppler Imaging ◽  
Retinal Capillary

Abstract. Introduction: To investigate the effects of a lutein complex supplementation on ocular blood flow in healthy subjects. Materials and Methods: Sixteen healthy female patients (mean age 36.8 ± 12.1 years) were enrolled in this randomized, placebo-controlled, double-blinded, two-period crossover study. Subjects received daily an oral dose of the lutein with synergistic phytochemicals complex (lutein (10 mg), ascorbic acid (500 mg), tocopherols (364 mg), carnosic acid (2.5 mg), zeaxanthin (2 mg), copper (2 mg), with synergistic effects in reducing pro-inflammatory mediators and cytokines when administered together in combination) and placebo during administration periods. Measurements were taken before and after three-week supplementation periods, with crossover visits separated by a three-week washout period. Data analysis included blood pressure, heart rate, intraocular pressure, visual acuity, contrast sensitivity detection, ocular perfusion pressure, confocal scanning laser Doppler imaging of retinal capillary blood flow, and Doppler imaging of the retrobulbar blood vessels. Results: Lutein complex supplementation produced a statistically significant increase in mean superior retinal capillary blood flow, measured in arbitrary units (60, p = 0.0466) and a decrease in the percentage of avascular area in the superior (−0.029, p = 0.0491) and inferior (−0.023, p = 0.0477) retina, as well as reduced systolic (−4.06, p = 0.0295) and diastolic (−3.69, p = 0.0441) blood pressure measured in mmHg from baseline. Data comparison between the two supplement groups revealed a significant decrease in systemic diastolic blood pressure (change from pre- to post-treatment with lutein supplement (mean (SE)): −3.69 (1.68); change from pre- to post-treatment with placebo: 0.31 (2.57); p = 0.0357) and a significant increase in the peak systolic velocity (measured in cm/sec) in the central retinal artery (change from pre- to post-treatment with lutein supplement: 0.36 (0.19); change from pre- to post-treatment with placebo: −0.33 (0.21); p = 0.0384) with lutein complex supplement; data analyses from the placebo group were all non-significant. Discussion: In healthy participants, oral administration of a lutein phytochemicals complex for three weeks produced increased ocular blood flow biomarkers within retinal vascular beds and reduced diastolic blood pressure compared to placebo.

Patterns of Cerebral Blood Flow and Systemic Hemodynamics During Arithmetic Processing

2008 ◽  
Vol 22 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Natalie Werner ◽  
Neval Kapan ◽  
Gustavo A. Reyes del Paso
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Doppler Sonography ◽  
Transcranial Doppler Sonography ◽  
Systemic Hemodynamics ◽  
Heart Period ◽  
Blood Flow Velocities ◽  
Flow Velocities

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.

COMPARISON OF ANTIHYPERTENSIVE EFFECT OF MOXONIDINE VERSUS CLONIDINE IN RENAL FAILURE PATIENTS.

2018 ◽  
Vol 6 (9) ◽  
Author(s):  
DR.MATHEW GEORGE ◽  
DR.LINCY JOSEPH ◽  
MRS.DEEPTHI MATHEW ◽  
ALISHA MARIA SHAJI ◽  
BIJI JOSEPH ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Failure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Antihypertensive Effect ◽  
The Body ◽  
Ability To Work ◽  
Blood Flows

Blood pressure is the force of blood pushing against blood vessel walls as the heart pumps out blood, and high blood pressure, also called hypertension, is an increase in the amount of force that blood places on blood vessels as it moves through the body. Factors that can increase this force include higher blood volume due to extra fluid in the blood and blood vessels that are narrow, stiff, or clogged(1). High blood pressure can damage blood vessels in the kidneys, reducing their ability to work properly. When the force of blood flow is high, blood vessels stretch so blood flows more easily. Eventually, this stretching scars and weakens blood vessels throughout the body, including those in the kidneys.

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