Effect of growth hormone and thyroxin on cardiovascular system of hypophysectomized rats

1963 ◽  
Vol 204 (2) ◽  
pp. 279-283 ◽  
Author(s):  
Margaret Beznak
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiovascular System ◽  
Normal Function ◽  
Normal Response ◽  
Cardiovascular Parameters ◽  
Hypophysectomized Rats ◽  
The Right

Growth hormone, thyroxin, or growth hormone and thyroxin were given for a period of 4 weeks to rats hypophysectomized 2–3 months previously. The effect of these treatments on blood pressure, weight and rate of the heart, cardiac output, and work was measured under basal conditions and during acute loading (infusion of polyvinylpyrrolidone into the right side of the heart) as well as during chronic loading (constriction of the aorta). The changes in cardiovascular parameters in the basal state due to hypophysectomy could all be reversed by thyroxin treatment. Thyroxin alone was inadequate in restoring the response of the hearts to either acute or chronic loading. Growth hormone in combination with thyroxin could restore or even exaggerate the normal response to both chronic and acute loading as well as maintain the basal parameters. Growth hormone itself had comparatively little effect; it caused some increase in the weight of the heart and stroke volume. It is concluded that both thyroxin and growth hormone are necessary for the normal function of the cardiovascular system.

The Effects of Caffeine Intake on Cardiovascular Parameters in Sleep Deprived Medical Residents

2019 ◽  
Vol 70 (4) ◽  
pp. 1445-1448
Author(s):  
Ioana Raluca Papacocea ◽  
Ioana Anca Badarau ◽  
Mariana Catalina Ciornei ◽  
Sofia Lider Burciulescu ◽  
Marius Toma Papacocea
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Sleep Deprivation ◽  
Medical Residents ◽  
Caffeine Intake ◽  
Caffeine Consumption ◽  
Cardiovascular Parameters ◽  
Arterial Blood

Physicians and medical residents are particularly affected by sleep deprivation are, especially in East European countries. The aim of our study is to analyze the effect of caffeine intake on cardiovascular functions in sleep deprived residents (clinicians in-training) after continuous 24h on-call duty. 26 medical residents aged between 22-33 years old, 12 men and 14 women, who began their activity at 2 pm were included. Each subject consumed coffee or caffeinated drinks such as Coca cola during this period, after 2 am, expressed in caffeine units. We have evaluated their cardiovascular function using impedance cardiography (ICG-M501) and blood pressure measurement using the manometric method, before (at 7 pm) and after caffeine consumption (at 7 am), during one night of on-call duty. Surprisingly, after caffeine consumption, all subjects have had a decrease of the heart rate after one night of sleep deprivation (from mean: 83 b/min before to 69.73 b/min after, p = 0.000), also the mean arterial blood pressure is lower after the overnight call (from mean: 95.3 mmHg before to 88.9 mmHg after). Moreover, cardiac output, stroke volume and cardiac index decreases along with an increase of peripheral vascular resistance. Caffeine intake exerts a paradoxical effect on sleep deprived subjects; acute sleep loss, due to continuously, intense on-call work, modifies several cardiovascular parameters, such as heart rate, blood pressures, stroke volume and cardiac output.

scholarly journals Bed-Based Ballistocardiography: Dataset and Ability to Track Cardiovascular Parameters

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 156
Author(s):  
Charles Carlson ◽  
Vanessa-Rose Turpin ◽  
Ahmad Suliman ◽  
Carl Ade ◽  
Steve Warren ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Stroke Volume ◽  
Systolic Blood Pressure ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Health Assessment ◽  
Initial Study ◽  
Pearson Correlation Coefficient ◽  
Medical Systems ◽  
Cardiovascular Parameters

Background: The goal of this work was to create a sharable dataset of heart-driven signals, including ballistocardiograms (BCGs) and time-aligned electrocardiograms (ECGs), photoplethysmograms (PPGs), and blood pressure waveforms. Methods: A custom, bed-based ballistocardiographic system is described in detail. Affiliated cardiopulmonary signals are acquired using a GE Datex CardioCap 5 patient monitor (which collects ECG and PPG data) and a Finapres Medical Systems Finometer PRO (which provides continuous reconstructed brachial artery pressure waveforms and derived cardiovascular parameters). Results: Data were collected from 40 participants, 4 of whom had been or were currently diagnosed with a heart condition at the time they enrolled in the study. An investigation revealed that features extracted from a BCG could be used to track changes in systolic blood pressure (Pearson correlation coefficient of 0.54 +/− 0.15), dP/dtmax (Pearson correlation coefficient of 0.51 +/− 0.18), and stroke volume (Pearson correlation coefficient of 0.54 +/− 0.17). Conclusion: A collection of synchronized, heart-driven signals, including BCGs, ECGs, PPGs, and blood pressure waveforms, was acquired and made publicly available. An initial study indicated that bed-based ballistocardiography can be used to track beat-to-beat changes in systolic blood pressure and stroke volume. Significance: To the best of the authors’ knowledge, no other database that includes time-aligned ECG, PPG, BCG, and continuous blood pressure data is available to the public. This dataset could be used by other researchers for algorithm testing and development in this fast-growing field of health assessment, without requiring these individuals to invest considerable time and resources into hardware development and data collection.

Long-term hemodynamic actions of atrial natriuretic factor (99-126) in conscious sheep

1988 ◽  
Vol 254 (4) ◽  
pp. H811-H815 ◽  
Author(s):  
D. G. Parkes ◽  
J. P. Coghlan ◽  
J. G. McDougall ◽  
B. A. Scoggins
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Blood Volume ◽  
Total Peripheral Resistance ◽  
Atrial Natriuretic Factor ◽  
Peripheral Resistance ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

The hemodynamic and metabolic effects of long-term (5 day) infusion of human atrial natriuretic factor (ANF) were examined in conscious chronically instrumented sheep. Infusion of ANF at 20 micrograms/h, a rate below the threshold for an acute natriuretic effect, decreased blood pressure by 9 +/- 1 mmHg on day 5, associated with a fall in calculated total peripheral resistance. On day 1, ANF reduced cardiac output, stroke volume, and blood volume, effects that were associated with an increase in heart rate and calculated total peripheral resistance and a small decrease in blood pressure. On days 4 and 5 there was a small increase in urine volume and sodium excretion. On day 5 an increase in water intake and body weight was observed. No change was seen in plasma concentrations of renin, arginine vasopressin, glucose, adrenocorticotropic hormone, or protein. This study suggests that the short-term hypotensive effect of ANF results from a reduction in cardiac output associated with a fall in both stroke volume and effective blood volume. However, after 5 days of infusion, ANF lowers blood pressure via a reduction in total peripheral resistance.

In the Loop—Left Ventricular Pressures

2011 ◽  
pp. 42-47
Author(s):  
James R. Munis
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Aortic Valve ◽  
Left Ventricle ◽  
Stroke Volume ◽  
Cardiovascular System ◽  
Aortic Root ◽  
Left Ventricular ◽  
Root Pressure ◽  
The Third

We've already looked at 2 types of pressure that affect physiology (atmospheric and hydrostatic pressure). Now let's consider the third: vascular pressures that result from mechanical events in the cardiovascular system. As you already know, cardiac output can be defined as the product of heart rate times stroke volume. Heart rate is self-explanatory. Stroke volume is determined by 3 factors—preload, afterload, and inotropy—and these determinants are in turn dependent on how the left ventricle handles pressure. In a pressure-volume loop, ‘afterload’ is represented by the pressure at the end of isovolumic contraction—just when the aortic valve opens (because the ventricular pressure is now higher than aortic root pressure). These loops not only are straightforward but are easier to construct just by thinking them through, rather than by memorization.

Effect of Growth Hormone Preparations on Cardiac Hypertrophy and Blood Pressure of Hypophysectomized Rats

1956 ◽  
Vol 184 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Margaret Beznák
Keyword(s):  
Blood Pressure ◽  
Growth Hormone ◽  
Cardiac Hypertrophy ◽  
Body Growth ◽  
Bovine Growth Hormone ◽  
Aortic Constriction ◽  
Hypophysectomized Rats ◽  
Crystalline Growth

Of three growth hormone preparations only one (PGH 163-208A, Armour) restored cardiac hypertrophy and hypertension on aortic constriction in hypophysectomized rats near to the level seen in normal rats. The same aortic constriction caused no increase in the weight of the heart and no hypertension in untreated hypophysectomized rats and in similar rats treated with a bovine growth hormone preparation (R 285-174, Armour) or crystalline growth hormone (Dr. Li, Berkeley). The different action of the three preparations was not connected with their effect on appetite and on body growth. ACTH, 5 mg/rat/day, caused adrenal hypertrophy in hypophysectomized rats without raising their blood pressure. The weight of the heart and particularly the blood pressure after aortic constriction were, however, greater in hypophysectomized rats treated with ACTH than in their nontreated controls.

Effect of sympathetic blockade on diurnal variation of hemodynamic patterns

1989 ◽  
Vol 256 (3) ◽  
pp. R778-R785 ◽  
Author(s):  
M. I. Talan ◽  
B. T. Engel
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Base Line ◽  
Sympathetic Blockade ◽  
Selective Blockade ◽  
Arterial Blood

Heart rate, stroke volume, and intra-arterial blood pressure were monitored continuously in each of four monkeys, 18 consecutive h/day for several weeks. The mean heart rate, stroke volume, cardiac output, systolic and diastolic blood pressure, and total peripheral resistance were calculated for each minute and reduced to hourly means. After base-line data were collected for approximately 20 days, observation was continued for equal periods of time under conditions of alpha-sympathetic blockade, beta-sympathetic blockade, and double sympathetic blockade. This was achieved by intra-arterial infusion of prazosin, atenolol, or a combination of both in concentration sufficient for at least 75% reduction of response to injection of agonists. The results confirmed previous findings of a diurnal pattern characterized by a fall in cardiac output and a rise in total peripheral resistance throughout the night. This pattern was not eliminated by selective blockade, of alpha- or beta-sympathetic receptors or by double sympathetic blockade; in fact, it was exacerbated by sympathetic blockade, indicating that the sympathetic nervous system attenuates these events. Because these findings indicate that blood volume redistribution is probably not the mechanism mediating the observed effects, we have hypothesized that a diurnal loss in plasma volume may mediate the fall in cardiac output and that the rise in total peripheral resistance reflects a homeostatic regulation of arterial pressure.

Constancy of stroke volume in ventricular responses to exertion

1959 ◽  
Vol 196 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Robert F. Rushmer
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Response ◽  
Indirect Measurements ◽  
Increase Stroke Volume ◽  
Normal Man ◽  
The Right ◽  
Response To Exercise ◽  
Indicator Dilution Techniques

Diastolic and systolic dimensions of the left ventricle and the free wall of the right ventricle in intact dogs are affected little by spontaneous exercise. The concept that stroke volume and heart rate in normal man increase by about the same relative amounts was derived from estimations of cardiac output, particularly in athletes, based upon indirect measurements using foreign gases or CO2. Data for man obtained with the modern cardiac catheterization or indicator dilution techniques confirm the impression derived from intact dogs that increased stroke volume is neither an essential nor a characteristic feature of the normal cardiac response to exercise. Stroke volume undoubtedly increases whenever cardiac output is increased with little change in heart rate (e.g. in athletes or in patients with chronic volume loads on the heart). Tachycardia produced experimentally with an artificial pacemaker in a resting dog causes a marked reduction in diastolic and systolic dimensions and in the stroke change of dimensions. The factors generally postulated to increase stroke volume during normal exercise may prevent the reduction in stroke volume accompanying tachycardia.

Systemic hemodynamic determinants of blood pressure in women: age, physical activity, and hormone replacement

1997 ◽  
Vol 273 (2) ◽  
pp. H777-H785 ◽  
Author(s):  
B. E. Hunt ◽  
K. P. Davy ◽  
P. P. Jones ◽  
C. A. DeSouza ◽  
R. E. Van Pelt ◽  
...  
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Hormone Replacement ◽  
Systemic Hemodynamic ◽  
Arterial Blood ◽  
Age Related ◽  
Hemodynamic Determinants

We tested the hypothesis that the age-related changes in systemic hemodynamic determinants of arterial blood pressure in healthy women are related to physical activity and hormone replacement status. We studied 66 healthy, normotensive premenopausal (21-35 yr) and postmenopausal (50-72 yr) sedentary and endurance-trained women under supine resting conditions. Mean blood pressure was 7 mmHg higher in sedentary post- compared with premenopausal women, which was associated with an 11-mmHg higher systolic blood pressure, a 25% lower stroke volume and cardiac output, and a 50% higher systemic vascular resistance (all P < 0.05). Absolute (ml) levels of total blood volume did not differ across age, but resting oxygen consumption was approximately 35% lower in the postmenopausal women (P < 0.05). The elevations in mean and systolic blood pressures with age were similar in endurance-trained runners, but, in contrast to the sedentary women, the elevations were not associated with significant age-related differences in cardiac output, stroke volume, or oxygen consumption, and only a modest (15%) increase in systemic vascular resistance (P = 0.06). Postmenopausal swimmers demonstrated the same systemic hemodynamic profile as that of postmenopausal runners, indicating a nonspecific influence of the endurance-trained state. Blood pressure and its systemic hemodynamic determinants did not differ in postmenopausal users compared with those of nonusers of hormone replacement therapy. Resting oxygen consumption was the strongest physiological correlate of cardiac output in the overall population (r = 0.65, P < 0.001). We conclude that 1) the increases in arterial blood pressure at rest with age in healthy normotensive women are not obviously related to habitual physical activity status; 2) the systemic hemodynamic determinants of the age-related elevations in blood pressure are fundamentally different in sedentary vs. active women, possibly due, in part, to an absence of decline in resting oxygen consumption in the latter; and 3) systemic hemodynamics at rest are not different in healthy normotensive postmenopausal users vs. nonusers of estrogen-based hormone replacement.

The underwater environment: cardiopulmonary, thermal, and energetic demands

2009 ◽  
Vol 106 (1) ◽  
pp. 276-283 ◽  
Author(s):  
D. R. Pendergast ◽  
C. E. G. Lundgren
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Time Dependent ◽  
Breath Holding ◽  
Peripheral Blood Flow ◽  
Short Term ◽  
Underwater Environment ◽  
Maximal Cardiac Output

Water covers over 75% of the earth, has a wide variety of depths and temperatures, and holds a great deal of the earth's resources. The challenges of the underwater environment are underappreciated and more short term compared with those of space travel. Immersion in water alters the cardio-endocrine-renal axis as there is an immediate translocation of blood to the heart and a slower autotransfusion of fluid from the cells to the vascular compartment. Both of these changes result in an increase in stroke volume and cardiac output. The stretch of the atrium and transient increase in blood pressure cause both endocrine and autonomic changes, which in the short term return plasma volume to control levels and decrease total peripheral resistance and thus regulate blood pressure. The reduced sympathetic nerve activity has effects on arteriolar resistance, resulting in hyperperfusion of some tissues, which for specific tissues is time dependent. The increased central blood volume results in increased pulmonary artery pressure and a decline in vital capacity. The effect of increased hydrostatic pressure due to the depth of submersion does not affect stroke volume; however, a bradycardia results in decreased cardiac output, which is further reduced during breath holding. Hydrostatic compression, however, leads to elastic loading of the chest wall and negative pressure breathing. The depth-dependent increased work of breathing leads to augmented respiratory muscle blood flow. The blood flow is increased to all lung zones with some improvement in the ventilation-perfusion relationship. The cardiac-renal responses are time dependent; however, the increased stroke volume and cardiac output are, during head-out immersion, sustained for at least hours. Changes in water temperature do not affect resting cardiac output; however, maximal cardiac output is reduced, as is peripheral blood flow, which results in reduced maximal exercise performance. In the cold, maximal cardiac output is reduced and skin and muscle are vasoconstricted, resulting in a further reduction in exercise capacity.

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