Effect of ambient temperature on cardiovascular parameters in rats and mice: a comparative approach

2004 ◽  
Vol 287 (2) ◽  
pp. R391-R396 ◽  
Author(s):  
Steven J. Swoap ◽  
J. Michael Overton ◽  
Graham Garber
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Volume Ratio ◽  
Ambient Air ◽  
Comparative Approach ◽  
Time Interval ◽  
Cardiovascular Parameters ◽  
Arterial Blood ◽  
Air Temperatures ◽  
Rats And Mice

Ambient air temperatures (Ta) of <6°C or >29°C have been shown to induce large changes in arterial blood pressure and heart rate in homeotherms. The present study was designed to investigate whether small incremental changes in Ta, such as those found in typical laboratory settings, would have an impact on blood pressure and other cardiovascular parameters in mice and rats. We predicted that small decreases in Ta would impact the cardiovascular parameters of mice more than rats due to the increased thermogenic demands resulting from a greater surface area-to-volume ratio in mice relative to rats. Cardiovascular parameters were measured with radiotelemetry in mice and rats that were housed in temperature-controlled environments. The animals were exposed to different Ta every 72 h, beginning at 30°C and incrementally decreasing by 4°C at each time interval to 18°C and then incrementally increasing back up to 30°C. As Ta decreased, mean blood pressure, heart rate, and pulse pressure increased significantly for both mice (1.6 mmHg/°C, 14.4 beats·min−1·°C−1, and 0.8 mmHg/°C, respectively) and rats (1.2 mmHg/°C, 8.1 beats·min−1·°C−1, and 0.8 mmHg/°C, respectively). Thus small changes in Ta significantly impact the cardiovascular parameters of both rats and mice, with mice demonstrating a greater sensitivity to these Ta changes.

scholarly journals Oral clonidine versus intravenous fentanyl in attenuation of hemodynamic responses to larngoscopy and endotracheal intubation: a comparative study

2019 ◽  
Vol 6 (3) ◽  
pp. 623
Author(s):  
Rukmini G. ◽  
Srinivas M. Reddy
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Endotracheal Intubation ◽  
Hemodynamic Responses ◽  
Cardiovascular Parameters ◽  
Oral Clonidine ◽  
Arterial Blood ◽  
Fentanyl Group

Background: During endotracheal intubation, it has been observed that there is evolvement of the responses of the circulatory in nature. These are difficult to control using the IV anesthetic drugs. Hence various agents are tried to overcome this drawback. Objective of research work was to study efficacy of oral clonidine on hemodynamic responses compared to IV fentanyl while patients undergo larngoscopy and endotracheal intubation.Methods: The patients were allocated into two groups of 30 each. i.e. 30 patients in clonidine group and 30 patients in fentanyl group. All the patients received were pre-medicated with glycoprrolate 0.2mg, ondansetron 4mg and tramadol 1mg/kg body weight. Cardiovascular parameters (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure,) were recorded at the following intervals: pre-induction, after induction, at endotracheal intubation, one minute, three minutes and five minutes after intubation.Results: The heart rate was significantly more at various intervals in patients who belonged to fentanyl group and it was significantly lesser in clonidine group. The systolic blood pressure was significantly more at various intervals in patients who belonged to fentanyl group and it was significantly lesser in clonidine group. The diastolic blood pressure was significantly more at various intervals in patients who belonged to fentanyl group and it was significantly lesser in clonidine group. Similar was the case with mean arterial blood pressure.Conclusions: Clonidine has been found to be more effective than IV fentanyl in stabilizing the cardiovascular parameters. Not only that orally it is easier to administer and cost effective.

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.

Neural contribution to the effect of glucagon-like peptide-1-(7—36) amide on arterial blood pressure in rats

1999 ◽  
Vol 277 (5) ◽  
pp. E784-E791 ◽  
Author(s):  
José Manuel Barragán ◽  
John Eng ◽  
Raquel Rodríguez ◽  
Enrique Blázquez
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Intravenous Administration ◽  
Cardiovascular Parameters ◽  
Arterial Blood ◽  
Neural Information ◽  
Bilateral Vagotomy ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

This study was designed to determine the contribution of the central nervous system (CNS) to the effects of glucagon-like peptide-1-(7—36) amide (tGLP-1) on arterial blood pressure and heart rate in rats. Accordingly, intracerebroventricular administration of the peptide produced an increase in cardiovascular parameters, which was blocked by previous administration of exendin-(9—39) through the same route, but not when it was intravenously injected. Intravenous administration of tGLP-1 produced a significant increase in arterial blood pressure and heart rate, which was blocked by the previous intracerebroventricular or intravenous administration of exendin-(9—39). Bilateral vagotomy blocked the stimulating effect of intracerebroventricular tGLP-1 administration on arterial blood pressure and heart rate. Also, bilateral vagotomy prevented the blocking effect of intracerebroventricular but not of intravenous exendin-(9—39) on cardiovascular parameters after intravenous administration of tGLP-1. These findings suggest that the action of tGLP-1 on cardiovascular parameters is under a dual control generated in the CNS and in peripheral structures and that the neural information emerging in the brain is transmitted to the periphery through the vagus nerve.

scholarly journals Some Cardio-Pulmonary Effects of Infra-Renal Clamping of the Abdominal Aorta

1978 ◽  
Vol 6 (1) ◽  
pp. 44-48 ◽  
Author(s):  
H. Askitopolou ◽  
C. A. Young ◽  
M. Morgan ◽  
M. K. Sykes
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Abdominal Aorta ◽  
Volume Ratio ◽  
Blood Gases ◽  
Arterial Blood Gases ◽  
Circulating Blood Volume ◽  
Arterial Blood ◽  
Renal Vessels ◽  
Before And After

No significant changes were found in heart rate, blood pressure, cardiac output, arterial blood gases or physiological deadspace: tidal volume ratio before and after clamping and unclamping the abdominal aorta below the renal vessels. Nevertheless, drugs should be available to reduce the afterload on the heart if any evidence of myocardial ischaemia appears during the period of aortic clamping. The importance of maintaining an adequate circulating blood volume at all times is stressed.

Compression Stocking Length Effects on Arterial Blood Pressure and Heart Rate Following Head-Up Tilt in Healthy Volunteers

2014 ◽  
Vol 63 (6) ◽  
pp. 435-438 ◽  
Author(s):  
Kunihiko Tanaka ◽  
Shiori Tokumiya ◽  
Yumiko Ishihara ◽  
Yumiko Kohira ◽  
Tetsuro Katafuchi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Arterial Blood Pressure ◽  
Compression Stocking ◽  
Arterial Blood ◽  
Head Up Tilt ◽  
Length Effects

A Comparison of the Acute Haemodynamic Effects of Propranolol and Pindolol at Rest and during Supine Exercise in Man

1980 ◽  
Vol 59 (s6) ◽  
pp. 465s-468s ◽  
Author(s):  
T. L. Svendsen ◽  
J. E. Carlsen ◽  
O. Hartling ◽  
A. McNair ◽  
J. Trap-Jensen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Response Curves ◽  
Receptor Blocking ◽  
Artery Pressure ◽  
Arterial Blood ◽  
Β Receptor

1. Dose-response curves for heart rate, cardiac output, arterial blood pressure and pulmonary artery pressure were obtained in 16 male patients after intravenous administration of three increasing doses of pindolol, propranolol or placebo. All patients had an uncomplicated acute myocardial infarction 6–8 months earlier. 2. The dose-response curves were obtained at rest and during repeated bouts of supine bicycle exercise. The cumulative dose amounted to 0.024 mg/kg body weight for pindolol and to 0.192 mg/kg body weight for propranolol. 3. At rest propranolol significantly reduced heart rate and cardiac output by 12% and 15% respectively. Arterial mean blood pressure was reduced by 9.2 mmHg. Mean pulmonary artery pressure increased significantly by 2 mmHg. Statistically significant changes in these variables were not seen after pindolol or placebo. 4. During exercise pindolol and propranolol both reduced cardiac output, heart rate and arterial blood pressure to the same extent. After propranolol mean pulmonary artery pressure was increased significantly by 3.6 mmHg. Pindolol and placebo did not change pulmonary artery pressure significantly. 5. The study suggests that pindolol may offer haemodynamic advantages over β-receptor-blocking agents without intrinsic sympathomimetic activity during low activity of the sympathetic nervous system, and may be preferable in situations where the β-receptor-blocking effect is required only during physical or psychic stress.

scholarly journals Salt sensitivity of blood pressure in NKCC1-deficient mice

2008 ◽  
Vol 295 (4) ◽  
pp. F1230-F1238 ◽  
Author(s):  
Soo Mi Kim ◽  
Christoph Eisner ◽  
Robert Faulhaber-Walter ◽  
Diane Mizel ◽  
Susan M. Wall ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Wheel Running ◽  
Plasma Renin ◽  
Pressure Change ◽  
Standard Diet ◽  
Wild Type ◽  
Vascular Effects ◽  
Arterial Blood ◽  
Deficient Mice

NKCC1 is a widely expressed isoform of the Na-2Cl-K cotransporter that mediates several direct and indirect vascular effects and regulates expression and release of renin. In this study, we used NKCC1-deficient (NKCC1−/−) and wild-type (WT) mice to assess day/night differences of blood pressure (BP), locomotor activity, and renin release and to study the effects of high (8%) or low (0.03%) dietary NaCl intake on BP, activity, and the renin/aldosterone system. On a standard diet, 24-h mean arterial blood pressure (MAP) and heart rate determined by radiotelemetry, and their day/night differences, were not different in NKCC1−/− and WT mice. Spontaneous and wheel-running activities in the active night phase were lower in NKCC1−/− than WT mice. In NKCC1−/− mice on a high-NaCl diet, MAP increased by 10 mmHg in the night without changes in heart rate. In contrast, there was no salt-dependent blood pressure change in WT mice. MAP reductions by hydralazine (1 mg/kg) or isoproterenol (10 μg/mouse) were significantly greater in NKCC1−/− than WT mice. Plasma renin (PRC; ng ANG I·ml−1·h−1) and aldosterone (aldo; pg/ml) concentrations were higher in NKCC1−/− than WT mice (PRC: 3,745 ± 377 vs. 1,245 ± 364; aldo: 763 ± 136 vs. 327 ± 98). Hyperreninism and hyperaldosteronism were found in NKCC1−/− mice during both day and night. High Na suppressed PRC and aldosterone in both NKCC1−/− and WT mice, whereas a low-Na diet increased PRC and aldosterone in WT but not NKCC1−/− mice. We conclude that 24-h MAP and MAP circadian rhythms do not differ between NKCC1−/− and WT mice on a standard diet, probably reflecting a balance between anti- and prohypertensive factors, but that blood pressure of NKCC1−/− mice is more sensitive to increases and decreases of Na intake.

scholarly journals Cardiovascular effects of lumbar epidural anaesthesia in isoflurane-anaesthetised pigs during surgical removal of the liver

2009 ◽  
Vol 80 (1) ◽  
Author(s):  
G.F. Stegmann
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Abdominal Surgery ◽  
Epidural Anaesthesia ◽  
Cardiovascular Effects ◽  
Surgical Removal ◽  
Arterial Blood ◽  
Combined Administration ◽  
Lumbar Epidural Anaesthesia ◽  
Surgical Preparation

In humans the combined administration of epidural anaesthesia and inhalation anaesthesia may result in cardiovascular instability associated with decreases in heart rate and blood pressure. Anaesthesia was induced with a combination of midazolam / ketamine in 18 female pigs with a mean body weight of 24.9±5.9 kg scheduled for surgical removal of the liver. After tracheal intubation, anaesthesia was maintained on a circle rebreathing circuit with isoflurane. Epidural anaesthesia was administered with ropivacaine (AL-group, n=8) at 0.2 mℓ / kg of a 7.5 mg / mℓ solution to the anaesthetised animals. The A-group (n = 10) received isoflurane anaesthesia only. The vaporiser was set at 2.5 % for the A-group and 1.5 % for the AL-group. Heart rate, invasive systolic, diastolic, and mean arterial blood pressure were monitored. Comparisons were made between treatments and within treatments comparing variables during surgical preparation and abdominal surgery. Differences between treatments were not statistically significant (P > 0.05) during surgical preparation or during abdominal surgery. For within treatment groups, the differences between surgical preparation and abdominal surgery were statistically significant (P < 0.05) for heart rate in the A-group, but not statistically significant (P > 0.05) for the other variables. It is concluded that abdominal surgery may be associated with statistically significant changes in heart rate in isoflurane-anaesthetised pigs and that the combined administration of epidural ropivacaine may prevent statistically significant changes in HR during abdominal surgery.

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