Central Blood Pressure and Heart Output in Surfaced and Submerged Frogs

1965 ◽  
Vol 42 (2) ◽  
pp. 339-357
Author(s):  
G. SHELTON ◽  
D. R. JONES
Keyword(s):  
Blood Pressure ◽  
Rana Pipiens ◽  
Pulse Wave ◽  
Diastolic Pressure ◽  
Peripheral Resistance ◽  
Systolic Pressure ◽  
Systemic Blood Pressure ◽  
Minute Volume ◽  
Central Blood Pressure ◽  
Systemic Blood

1. The systemic blood pressure of Rana pipiens and R. temporaria is slightly higher than the pulmocutaneous pressure at systole and much higher at diastole. The pulses differ in shape and a conus component can be seen in the systemic wave. 2. Submersion of the animal causes a fall in systolic pressure in both arches, the diastolic pressure remaining relatively constant. The shape of the pulse wave changes, the conus component being accentuated and visible in recordings from both arches. 3. Heart rate and stroke volume fall during submersion so that after 30 min. under water the minute volume may be 20-50% of the value at the surface. The heart becomes increasingly full of blood. 4. The differences in systemic and pulmocutaneous pressures are explained in terms of resistance, compliance and flow in lung and body circuits. The same general relationships persist during submersion but selective increases in peripheral resistance must occur to maintain the central blood pressure in face of falling heart output.

Control of Blood Pressure and the Distribution of Blood Flow

1991 ◽  
Vol 7 (S1) ◽  
pp. 79-84 ◽  
Author(s):  
Hans T. Versmold
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Systemic Blood Pressure ◽  
Adrenergic Innervation ◽  
Systemic Blood ◽  
Low Cardiac Output ◽  
Neurohumoral Control ◽  
The Brain

Systemic blood pressure (BP) is the product of cardiac output and total peripheral resistance. Cardiac output is controlled by the heart rate, myocardial contractility, preload, and afterload. Vascular resistance (vascular hindrance × viscosity) is under local autoregulation and general neurohumoral control through sympathetic adrenergic innervation and circulating catecholamines. Sympathetic innovation predominates in organs receivingflowin excess of their metabolic demands (skin, splanchnic organs, kidney), while innervation is poor and autoregulation predominates in the brain and heart. The distribution of blood flow depends on the relative resistances of the organ circulations. During stress (hypoxia, low cardiac output), a raise in adrenergic tone and in circulating catecholamines leads to preferential vasoconstriction in highly innervated organs, so that blood flow is directed to the brain and heart. Catecholamines also control the levels of the vasoconstrictors renin, angiotensin II, and vasopressin. These general principles also apply to the neonate.

scholarly journals Variation in carotid-femoral pulse wave velocity, augmentation pressure and augmentation index during different phases of menstrual cycle

2018 ◽  
Vol 2 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Nudrath Kahkashan ◽  
Mehnaaz Sameera Arifuddin ◽  
Mohammed Abdul Hannan Hazari ◽  
Safia Sultana ◽  
Farah Fatima ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Menstrual Cycle ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Diastolic Pressure ◽  
Augmentation Index ◽  
Arterial Compliance ◽  
Systolic Pressure ◽  
Augmentation Pressure

Physiological variation of estrogen and progesterone during menstrual cycle is well known. They not only have an effect on blood pressure control, but also seem to have a role in regulating arterial compliance. This study was done to find out whether there are any changes in central arterial parameters during different phases of menstrual cycle. Thirty female subjects in the age group of 18-22 years with normal, regular menstrual cycles participated in this prospective observational study at our teaching hospital. Anthropometric parameters were recorded. Blood pressure in all 4 limbs was recorded using cardiovascular risk analyzer-Periscope™ on Day 3rd to 5th (follicular phase), Day 12th to 14th (ovulation phase), Day 22nd to 24th (luteal phase) of their menstrual cycle. We collected blood samples during these three phases for estimation of estradiol and progesterone by ELISA technique. Analysis of variance and correlation statistics were done using SPSS 17.0 statistical software. No significant statistical changes were observed in systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, aortic systolic pressure, aortic diastolic pressure, aortic augmentation pressure, aortic index and pulse wave velocity during the three recorded phases of the menstrual cycle. There are many studies which correlate changes in peripheral artery blood pressure with different phases of menstrual cycle. But there is scarcity in data available which correlates central arterial pressures and arterial stiffness with natural hormonal variations in different phases of menstrual cycle. However, our results show that although there are subtle changes in blood pressure parameters along with estrogen and progesterone levels throughout the menstrual cycle, yet these were not statistically significant.

Blood pressure and hemodynamic responses after exercise in older hypertensives

1987 ◽  
Vol 63 (1) ◽  
pp. 270-276 ◽  
Author(s):  
J. M. Hagberg ◽  
S. J. Montain ◽  
W. H. Martin
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Essential Hypertension ◽  
Stroke Volume ◽  
Diastolic Pressure ◽  
Peripheral Resistance ◽  
Systolic Pressure ◽  
Vo2 Max ◽  
Lower Blood ◽  
Single Bout

Recently, systolic and diastolic blood pressure have been reported to be significantly lower for several hours after exercise than when measured at rest before exercise in individuals with essential hypertension. We sought to determine the hemodynamic mechanism underlying this reduction in blood pressure. Twenty-four men and women 60–69 yr of age with persistent essential hypertension completed one of the following protocols: exercise at 50% of maximum O2 consumption (VO2 max) followed by 1 h of recovery, exercise at 70% of VO2 max followed by 3 h of recovery, or a 4-h control study. Systolic pressure was significantly lower during recovery after both intensities of exercise, but diastolic pressure was unchanged. The lower blood pressure was primarily due to a reduction in cardiac output, since total peripheral resistance was increased throughout both recovery periods. Cardiac output was reduced in recovery because of a reduction in stroke volume. Heart rate was above, or no different from, that at rest before exercise. Changes in plasma volume could not entirely account for the reduction in stroke volume. Therefore, other mechanisms altering venous return and/or myocardial contractility appear to be responsible for the reduction in systolic blood pressure evident after a single bout of submaximal exercise in individuals with essential hypertension.

scholarly journals Variation of intraocular pressure comparing rebound (TONOVET Plus®) and applanation (TONO-PEN VET®) tonometry in New Zealand rabbits treated with Amlodipine®

2021 ◽  
Vol 16 (3) ◽  
pp. 10-27
Author(s):  
Javier Dario Murillo Arroyave ◽  
Sara M Robledo ◽  
Jaime Montaño ◽  
Sandra Patricia Acevedo
Keyword(s):  
Blood Pressure ◽  
Intraocular Pressure ◽  
New Zealand ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Systemic Blood Pressure ◽  
Applanation Tonometry ◽  
Control Group ◽  
New Zealand White Rabbits ◽  
New Zealand Rabbits

Rabbits have played an important role in ophthalmological research processes, however in the environment there has been a deficiency of sensitive equipment in measurement of intraocular pressure for this species. To compare intraocular pressure (IOP) measured with rebound (TONOVET Plus®) and applanation (TONO-PEN VET®) tonometry in healthy New Zealand rabbits treated with Amlodipine. Twelve healthy male New Zealand white rabbits, 5 months old; two groups with 6 individuals were used in this study. The experimental group was given Amlodipine® at a dose of 5 mg/kg, once a day for a month. Blood pressure and intraocular pressure were measurement before treatment and 6 h after treatment in a period of one month. A trend is noted where the group of animals treated with amlodipine® presents lower values than the control group, both in systolic and diastolic pressure. The systolic pressure of the control group showed an average of 116.5 ± 7.9 mmHg and 117.4 ± 8.9 mmHg and the treatment group showed an average of 113.6 ± 7.9 mmHg and 111.8 ± 10.0 mmHg (pretreatment and posttreatment respectively). Tonometry: the values obtained using the TONOVET Plus® (19 ± 3 mmHg) are on average higher than the values obtained using the TONO-PEN VET® (17 ± 3 mmHg). It was possible to demonstrate the relationship between systemic blood pressure and intraocular pressure in New Zealand white rabbits. Rebound tonometry showed less variability in results than applanation tonometry. This study confirmed that both tonometers are reliable for measuring IOP in rabbits.

scholarly journals Effects of Chronic Nicotine Inhalation on Systemic and Pulmonary Blood Pressure and Right Ventricular Remodeling in Mice

Hypertension ◽  
2020 ◽  
Vol 75 (5) ◽  
pp. 1305-1314 ◽  
Author(s):  
Joshua M. Oakes ◽  
Jiaxi Xu ◽  
Tamara M. Morris ◽  
Nicholas D. Fried ◽  
Charlotte S. Pearson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Left Ventricle ◽  
Right Ventricular ◽  
Cardiac Remodeling ◽  
Systolic Pressure ◽  
Systemic Blood Pressure ◽  
Right Ventricular Systolic Pressure ◽  
Systemic Blood ◽  
Ventricular Systolic Pressure ◽  
Chronic Nicotine

Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases; however, the role of nicotine in the pathogenesis of these diseases is incompletely understood. The purpose of this study was to examine the effects of chronic nicotine inhalation on the development of cardiovascular and pulmonary disease with a focus on blood pressure and cardiac remodeling. Male C57BL6/J mice were exposed to air (control) or nicotine vapor (daily, 12 hour on/12 hour off) for 8 weeks. Systemic blood pressure was recorded weekly by radio-telemetry, and cardiac remodeling was monitored by echocardiography. At the end of the 8 weeks, mice were subjected to right heart catheterization to measure right ventricular systolic pressure. Nicotine-exposed mice exhibited elevated systemic blood pressure from weeks 1 to 3, which then returned to baseline from weeks 4 to 8, indicating development of tolerance to nicotine. At 8 weeks, significantly increased right ventricular systolic pressure was detected in nicotine-exposed mice compared with the air controls. Echocardiography showed that 8-week nicotine inhalation resulted in right ventricular (RV) hypertrophy with increased RV free wall thickness and a trend of increase in RV internal diameter. In contrast, there were no significant structural or functional changes in the left ventricle following nicotine exposure. Mechanistically, we observed increased expression of angiotensin-converting enzyme and enhanced activation of mitogen-activated protein kinase pathways in the RV but not in the left ventricle. We conclude that chronic nicotine inhalation alters both systemic and pulmonary blood pressure with the latter accompanied by RV remodeling, possibly leading to progressive and persistent pulmonary hypertension.

scholarly journals ULTRASOUND PREDICTORS OF SURVIVAL IN NEWBORNS WITH A LEFT SIDE CONGENITAL DIAPHRAGMATIC HERNIA

2018 ◽  
Vol 22 (5) ◽  
pp. 235-240
Author(s):  
Irina Yu. Baryshnikova ◽  
E. A. Filippova ◽  
A. A. Burov ◽  
Yu. L. Podurovskaya ◽  
V. V. Zubkov ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Pulmonary Artery ◽  
Congenital Diaphragmatic Hernia ◽  
Diaphragmatic Hernia ◽  
Abdominal Cavity ◽  
Systolic Pressure ◽  
Systemic Blood Pressure ◽  
The Body ◽  
Systemic Blood

Introduction. Complex ultrasound diagnosis of the organ and, directly, cardiac function allows forming groups of prognostically significant risk factors for the development of complications in newborns with a congenital diaphragmatic hernia (CDH) and on their basis to select patients with the negative life expectancy. The determination of hemodynamic disorders as secondary ones will allow emphasizing the treatment on the elimination of the main pathology, which will lead to an improvement and/or normalization of cardiac activity. The aim of the work is to identify ultrasound markers of risk factors for complications in CDH newborns. Material and methods. In 32 left side CDH newborns at the age of 6-18 h of the 1st day of the life, there was performed an examination on the expanded echographic protocol. The indices studied included the end-diastolic volume (EDV) of the left ventricle (LV) indexed to the surface area of the body; the mass of the myocardium (MM) of the LV; index of the shape (IS) of the LV; the ratio of the pulmonary blood flow to the systemic (Qp/Qs); cardiac index (CI); the McGun index; the ratio of the systolic blood pressure (SBP) in the pulmonary artery (PA) to systemic arterial pressure (SAP); the ratio of the time of the systole to the time of the diastole of the right ventricle (RV); a marker of the total myocardial contractility; the presence of organs of the abdominal cavity in the pleural cavities on the affected side (the proportion of the liver, stomach, spleen). The results of the extended echocardiographic examination were correlated with the clinical data characterizing the severity of the patient’s condition in the perioperative period (duration of the artificial ventilation, the need for cardiotonic and inotropic therapy, the length of the stay in the hospital), the outcome of the disease after surgery. Results. The overall survival rate of CDH newborns was 78.2%. EDV, MM, IS, CI and the ratio of systolic pressure in the pulmonary artery to systemic blood pressure in the groups of deceased and surviving patients significantly differed on the 1st day of the life (p = 0.013, p = 0.037, p = 0.001 and p = 0.04, respectively ). Within the framework of binary logistic regression, only CI affects the outcome of the treatment of CDH newborns (OR = 43.8 at p = 0.029). CI less than 2 L/min/m2 is a predictor of death of CDH newborns. EDV (less than 26 ml/m2), MM (less than 37g/m2), the ratio of systolic pressure in the pulmonary artery to systemic blood pressure (more than 0.9) are additional markers affecting on the outcome of treatment for CDH newborns. Conclusion. CI is an independent index in predicting the outcome of the treatment of CDH newborns (OR = 43.8 at p = 0.029). EDV, MM, the ratio of systolic pressure in the pulmonary artery to systemic BP are additional markers in predicting the outcome of treatment of newborns with EDC. The presence of a portion of the liver, stomach, and spleen in the thoracic cavity has no statistical significance in predicting the outcome of treatment of such children.

scholarly journals The pharmacology of antihypertensive medicines

2020 ◽  
Vol 19 (2) ◽  
pp. 75-88
Author(s):  
V. A. Tsyrlin
Keyword(s):  
Blood Pressure ◽  
Vascular Tone ◽  
Peripheral Resistance ◽  
Blood Pressure Level ◽  
Circulatory System ◽  
Systemic Blood Pressure ◽  
Minute Volume ◽  
System Functioning ◽  
Regulation Mechanisms ◽  
Human Cardiovascular System

The lecture presents contemporary view on the human cardiovascular system organization. The mechanisms determining the systemic blood pressure level are shown; the factors regulating minute volume of blood circulation and peripheral resistance to blood flow are described. The mechanisms of neurogenic and basal vascular tone are noted, the role of humoral and endothelial regulation mechanisms of the artery lumen s is indicated. Based on the recent evidences of the circulatory system functioning, we gave a description of the main medicinal compounds used in clinical practice to decrease blood pressure. The pharmacological drugs decreasing neurogenic vascular tone and inhibiting basal vascular tone are indicated. The data of drug action, its pharmacodynamics and basic principles of combined use for the rational treatment of hypertension are presented. The lecture may be interesting to physiologists, pharmacologists, cardiologists, therapists, medical students and clinical residents.

Abstract 15241: Proteinase-activated Receptor 1 Antagonist Inhibited the Progression of Monocrotaline Induced Pulmonary Hypertension in Rats

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yukimitsu Kuwabara ◽  
Kohtaro Abe ◽  
Mayumi Hirano ◽  
Yoshitaka Hirooka ◽  
Kenji Sunagawa ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Pulmonary Hypertension ◽  
Survival Time ◽  
Median Survival ◽  
Median Survival Time ◽  
Systolic Pressure ◽  
Treatment Protocol ◽  
Systemic Blood Pressure ◽  
Therapeutic Effects ◽  
Systemic Blood

Introduction: Pulmonary hypertension (PH) is characterized by thrombus formation, vasoconstriction and vascular remodeling. The normal pulmonary artery, in contrast to the systemic artery, has a unique property to contract in response to thrombin via thrombin receptor Proteinase-activated receptor 1 (PAR1). Hypothesis: We hypothesized that PAR1 plays a key role in the pathogenesis and pathophysiology in PH and examined the therapeutic effects of PAR1 antagonist on PH. Methods and Results: Adult male SD rats developed PH after a single subcutaneous injection of 60 mg/kg monocrotaline (MCT) on day 0. The indexes of pulmonary vascular resistance (PVR: RV systolic pressure/cardiac output) and RV hypertrophy (RVH: RV/LV+septum) increased from 0.33±0.03 (normal, n=5) to 1.3±0.1 mmHg•min/mL (MCT, n=10, p<0.01) and from 0.28±0.01 (n=6) to 0.49±0.02 (n=15, p<0.01), respectively, on day 21. We administered PAR1 antagonist (atopaxar: 30mg/kg/day, p.o.) on day 0 (preventive protocol) or day 14 (treatment protocol) of MCT injection. In comparison with MCT rats, the preventive and treatment protocols significantly reduced PVR (0.68±0.09 and 0.89±0.11 mmHg•min/mL, n=8 and 10, p<0.01 and p<0.05) and RVH (0.37±0.02 and 0.40±0.03, n=10 and 12, p<0.01 and p<0.05). Atopaxar had no effect on systemic blood pressure. In the isolated perfused lung preparations, a bolus infusion of 300 nmol PAR1-activating peptide elevated pulmonary arterial pressure by 0.33±0.08 mmHg in the normal (n=6) and 11.8±2.4 mmHg in MCT (n=9; p<0.01 vs. normal), while attenuated in the preventive protocol (1.99±0.96 mmHg, n=6). Atopaxar significantly prolonged the survival periods of MCT rat (median survival time: 26 days, n=17) in both preventive (median survival time: more than 56 days, n=14, p<0.01) and treatment (median survival time: 30 days, n=17, p<0.05) protocols. Conclusion: The PAR1 activity increased in MCT rats. Inhibiting the increased activity of PAR1 was effective in preventing the progression of PH without decreasing systemic blood pressure. PAR1 is thus a potentially novel therapeutic target for the treatment of PH.

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