Circadian blood pressure and heart rate rhythms in mice

1999 ◽  
Vol 276 (2) ◽  
pp. R500-R504 ◽  
Author(s):  
Ping Li ◽  
Steven H. Sur ◽  
Ralph E. Mistlberger ◽  
Mariana Morris

The circadian pattern of mean arterial pressure (MAP) and heart rate (HR) was measured in C57BL mice with carotid arterial catheters. Cardiovascular parameters were recorded continuously with a computerized monitoring system at a sampling rate of 100 Hz. The tethered animals were healthy, showing stabilized drinking and eating patterns within 2 days of surgery and little loss of body weight. Analysis of the 24-h pattern of MAP and HR was conducted using data from 3–6 consecutive days of recording. A daily rhythm of MAP was evident in all mice, with group mean dark and light values of 101.4 ± 7.3 and 93.1 ± 2.9 mmHg, respectively. The group mean waveform was bimodal, with peak values evident early and late in the dark period, and a trough during the middle of the light period. The phase of maximum and minimum values showed low within-group variance. Mean heart rate was greater at night than during the day (561.9 ± 22.7 vs. 530.3 ± 22.3 beats/min). Peak values generally occurred at dark onset, and minimum values during the middle of both the dark and the light periods. We conclude that it is possible to perform measurements of circadian cardiovascular parameters in the mouse, providing new avenues for the investigation of genetic models.

PEDIATRICS ◽  
1978 ◽  
Vol 61 (1) ◽  
pp. 119-121
Author(s):  
Richard B. Shekelle ◽  
Shuguey Liu ◽  
William J. Raynor ◽  
Robert A. Miller

Schachter and colleagues observed that black newborns have a higher mean heart rate than white newborns during non-rapid eye movement sleep, and this observation reportedly has been repeated at other laboratories.1,2 In Schachter's experience, the racial difference has persisted through the sixth month of life.3 Since heart rate is correlated cross-sectionally with level of blood pressure in adults4 and adolescents,5 and since increased heart rate in young adults is associated prospectively with risk of hypertensive disease,6-8 a racial difference in heart rate of newborns might be related to the racial difference in risk of hypertension. For these reasons, we investigated differences in mean pulse rate between black and white children, using data collected by the National Health Examination Survey (NHES).


2021 ◽  
pp. 112067212110233
Author(s):  
Marcelina Sobczak ◽  
Magdalena Asejczyk ◽  
Malwina Geniusz

Objectives: The main goal of this research was to determine the differences between the values of intraocular pressure (IOP) in the supine and sitting positions, and to assess the effect of age and cardiovascular parameters. Methods: Seventy-two healthy adults were enrolled and classified into age groups: 20–30 years (group A), 31–40 years (group B), and 41–71 years (group C). Corneal biometry and cardiovascular parameters, such as heart rate (HR), were measured. IOP measurements were taken in the sitting position (IOPS) and in the supine position (IOPL) using the iCare® Pro tonometer. Results: A significant difference between the IOPS and IOPL in the entire cohort was found ( p < 0.001). Regarding the age subgroups, a significant difference ( p < 0.001) between the IOPS and IOPL was obtained in group A (2.6 ± 1.6 mmHg) and group C (1.5 ± 1.3 mmHg). There were no significant differences in the IOPS between groups. The highest IOP values were obtained for group A. The correlations between HR and IOPS are statistically significant for group A and group B, and for HR and IOPL-S for group B only. Multivariate analysis showed that HR has a significant influence on the difference in IOP in the two body positions. Conclusion: A statistically significant difference between the effect of age and the values of IOPS and IOPL was shown. Cardiovascular parameters showed some relevant statistical dependencies, but with a rather marginal significance in young people. The influence of body position for the measurement of IOP for healthy subjects does not seem to matter, despite the fact that there are some dependencies that are statistically significant.


1998 ◽  
Vol 66 (2) ◽  
pp. 383-387 ◽  
Author(s):  
M. Khalid ◽  
W. Haresign ◽  
D. G. Bradley

AbstractThis study consisted of two experiments. In experiment 1, stress responses of sheep which were restrained either in a laparoscopy cradle or a roll-over cradle were compared. The results of this experiment indicated that restraint in roll-over cradle is less (P < 0·05) stressful than that in a laparoscopy cradle when assessed in terms of the elevation and duration of both the mean heart rate and plasma cortisol responses. Experiment 2 compared the stress responses of sheep subjected to restraint in a laparoscopy cradle, restraint in a laparoscopy cradle with intrauterine artificial insemination (AI) by laparoscopy, minimal restraint with cervical AI or restraint in a roll-over cradle plus foot-trimming. All treatments resulted in significant elevations in both heart rate and plasma cortisol concentrations (F < 0·001). The peak heart rate was significantly (P < 0·05) higher in ewes subjected to cervical AI than in those subjected to intrauterine insemination, with other treatments intermediate. The peak cortisol response did not differ among different treatments. The duration over which both the mean heart rate and -plasma cortisol concentrations remained significantly elevated above pre-treatment concentrations did not differ among treatment groups. The results of this study suggest that while restraint using a laparoscopy cradle is more stressful than that using a rollover cradle, the stress inflicted by intrauterine insemination by laparoscopy itself is no greater than that due to restraint using the laparoscopy cradle alone, cervical AI or the management practice offoot-trimming using a rollover cradle.


PEDIATRICS ◽  
1989 ◽  
Vol 83 (2) ◽  
pp. 240-243
Author(s):  
Myung K. Park ◽  
Da-Hae Lee

Indirect BP measurement was obtained in the right upper arm in 219 healthy newborn infants with the Dinamap monitor and was compared with values obtained from the calf to establish normative BP values and to help establish a diagnosis of hypertension and coarctation of the aorta in the newborn. There were 174 Mexican-Americans (79.5%), 33 whites (15.0%), and 12 blacks (5.5%). The width of the BP cuff was selected to be 0.4 to 0.5 times the circumference of the extremities. Three supine position readings of BPs and heart rate were obtained from each site and were averaged for statistical analyses. Mean arm BP values (±SD) of the neonate less than 36 hours of age were 62.6±6.9/38.9± 5.7 mm Hg (48.0±6.2 mm Hg). Neonates older than 36 hours had slightly but significantly (P&lt;.05) greater values (4 to 6 mm Hg) than did infants younger than 36 hours of age. Active neonates had values 6 to 10 mm Hg greater than quiet neonates (P&lt;.05). BP values in the calf obtained with the same-sized cuff were almost identical with those obtained from the arm. Differences in consecutively obtained arm and calf BPs (arm values minus calf values) were 1.1±7.7 mm Hg systolic, -0.01 ± 6.2 mm Hg diastolic, and 0.9 ±6.9 mm Hg mean pressures. Mean heart rate (±SD) of neonates less than 36 hours of age was 129.4± 13.2 beats per minute and that of neonates older than 36 hours of age was 139.4± 14.1 beats per minute. These results show the following: (1) arm BPs and calf BPs using the same-sized cuff are almost identical with mean values of approximately 65/ 41 mm Hg (50 mm Hg) in neonates one to three days of age, (2) arm BP of 75/49 mm Hg (59 mm Hg) or greater is in the hypertensive range, and (3) calf BPs that are less than arm BPs by mean + 1 SD (6 to 9 mm Hg) necessitate a thorough investigation for coarctation of the aorta.


2017 ◽  
Vol 26 (2) ◽  
pp. 116-21
Author(s):  
Arif H.M. Marsaban ◽  
Aldy Heriwardito ◽  
I G.N.A.D. Yundha

Background: Increased blood pressure and heart rate are the most frequent response to laryngoscopy which sometimes causes serious complications. Laryngoscopy technique and tools modification lessen the nociceptive stimulation, thus preventing hemodynamic response. BURP maneuver is used to lower Cormack-Lehane level, but it can cause additional pain stimulation during laryngoscopy. The aim of this study was to compare the cardiovascular response and the need of BURP maneuver during laryngoscopy between CMAC® and conventional Macintosh.Methods: A randomized, single blinded, control trial was performed to 139 subjects who underwent general anesthesia with endotracheal tube. Subjects were randomised into a control group (conventional Macintosh) and an intervention group (CMAC®). The cardiovascular parameters (systolic, dyastolic, mean arterial pressure, and heart rate) were measured prior to induction (T1). Midazolam 0.05 mg/kg and Fentanyl 2 micrograms/kg were given 2 minutes before the induction. Moreover, they were given propofol 1 mg/kg followed by propofol infusion of 10 mg/kg/hour and Atracurium 0.8–1 mg/kg. After TOF-0 cardiovascular parameters (T2) were remeasured, it was proceeded to laryngoscopy. When Cormack-Lehane 1–2 was reached (with or without BURP maneuver), cardiovascular parameters were measured again (T3).Results: Unpaired T-test showed that cardiovascular response during laryngoscopy were significantly lower in the intervention group compared to the control group (p<0.05). The need of BURP maneuver was significantly lower in the CMAC® group compared to the Convensional Macintosh group (13.9% vs 40.3%; p<0.05).Conclusion: Cardiovascular response and BURP maneuver during laryngoscopy with CMAC® were significantly lower compared to conventional Macintosh.


2015 ◽  
Vol 12 (8) ◽  
pp. 1133-1138 ◽  
Author(s):  
Meredith C. Peddie ◽  
Claire Cameron ◽  
Nancy Rehrer ◽  
Tracy Perry

Background:Interrupting sedentary time induces improvements in glucose metabolism; however, it is unclear how much activity is required to reduce the negative effects of prolonged sitting.Methods:Sixty-six participants sat continuously for 9 hours except for required bathroom breaks. Participants were fed meal replacement beverages at 60, 240 and 420 min. Blood samples were obtained hourly for 9 hours, with additional samples collected 30 and 45 min after each feeding. Responses were calculated as incremental area under the curve (iAUC) for plasma glucose, insulin and triglyceride. Participants wore a triaxial accelerometer and a heart rate monitor. Energy expenditure was estimated using indirect calorimetry.Results:After controlling for age, sex and BMI, every 100 count increase in accelerometer derived total movement was associated with a 0.06 mmol·L-1·9 hours decrease in glucose iAUC (95% CI 0.004–0.1; P = .035), but not associated with changes in insulin or triglyceride iAUC. Every 1 bpm increase in mean heart rate was associated with a 0.76 mmol·L-1·9 hours increase in triglyceride iAUC (95% CI 0.13–1.38).Conclusion:Accelerometer measured movement during periods of prolonged sitting can result in minor improvements in postprandial glucose metabolism, but not lipid metabolism.


1987 ◽  
Vol 62 (3) ◽  
pp. 1186-1191 ◽  
Author(s):  
J. W. Kozelka ◽  
G. W. Christy ◽  
R. D. Wurster

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.


2019 ◽  
Vol 12 (2) ◽  
pp. 26-32 ◽  
Author(s):  
Marta Gimunová ◽  
Hana Válková ◽  
Tomáš Kalina

Heart rate values are considered to be a significant indicator of individual fitness, intensity of exerciseand sympathetic activation. There are few studies in Czech literature focused on the heart rate in athleteswith intellectual disabilities. The aim of this study was to describe the characteristics of heart rateduring fifteen table tennis matches within the 23rd national tournament of the Czech Special OlympicsMovement. Ten participants (6 males, 4 females) who for at least 3 years train regularly and participatein table tennis competitions under the Special Olympics rules, were observed. Their heart rate wasmeasured using a sports tester Forerunner® 15, Garmin Ltd, which was fastened on the participant’schest during their game day. Heart rate values during the matches were statistically processed alongwith the matches’ duration and the resulting match scores. Correlation coefficients obtained from scatterplots show a statistically significant relationship of mean heart rate values during the match withthe resulting score, probably influenced by emotion and psychological stress associated with the matchloss. The effect of match duration on the heart rate was not statistically significant during observedmatches. Subsequent analysis of the body composition of the athletes showed that sixty percent ofthem were in the category of overweight or obesity. These results highlight the need to promote healthylifestyle and physical activity in the population with intellectual disabilities.


Sign in / Sign up

Export Citation Format

Share Document