scholarly journals Dissecting the Roles of the Autonomic Nervous System and Physical Activity on Circadian Heart Rate Fluctuations in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Nour Barazi ◽  
Nazari Polidovitch ◽  
Ryan Debi ◽  
Simona Yakobov ◽  
Robert Lakin ◽  
...  

Heart rate (HR) and blood pressure as well as adverse cardiovascular events show clear circadian patterns, which are linked to interdependent daily variations in physical activity and cardiac autonomic nerve system (ANS) activity. We set out to assess the relative contributions of the ANS (alone) and physical activity to circadian HR fluctuations. To do so, we measured HR (beats per minute, bpm) in mice that were either immobilized using isoflurane anesthesia or free-moving. Nonlinear fits of HR data to sine functions revealed that anesthetized mice display brisk circadian HR fluctuations with amplitudes of 47.1±7.4bpm with the highest HRs in middle of the dark (active) period (ZT 18: 589±46bpm) and lowest HRs in the middle of the light (rest) period (ZT 6: 497±54bpm). The circadian HR fluctuations were reduced by ~70% following blockade of cardiac parasympathetic nervous activity (PNA) with atropine while declining by <15% following cardiac sympathetic nerve activity (SNA) blockade with propranolol. Small HR fluctuation amplitudes (11.6±5.9bpm) remained after complete cardiac ANS blockade. Remarkably, circadian HR fluctuation amplitudes in freely moving, telemetrized mice were only ~32% larger than in anesthetized mice. However, after gaining access to running wheels for 1week, circadian HR fluctuations increase to 102.9±12.1bpm and this is linked directly to increased O2 consumption during running. We conclude that, independent of physical activity, the ANS is a major determinant of circadian HR variations with PNA playing a dominant role compared to SNA. The effects of physical activity to the daily HR variations are remarkably small unless mice get access to running wheels.

e-CliniC ◽  
2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Ribka Wowor ◽  
Frans Wantania ◽  
Fendy Pamolango

Abstract: Heart rate recovery (HRR) is a predictor of cardiovascular mortality in adult as well as a risk factor of diabetes mellitus and cardiovascular diseases. Heart rate recovery is affected by autonomic nerve system and interestingly, athletes have more effective autonomic nerve system than the non-athletes. This was an observational descriptive study with a cross-sectional design. Subjects were 15 adult trained males with central obesity and 15 untrained males without central obesity. Central obesity was determined if abdominal circumferences was above 90 cm. The treadmill test with Bruce protocol was used to evaluate the HHR at the second minute of recovery which was abnormal if the HRR below 42 times per minute. The non-tailed T test was used to determine the comparison of HRR between trained central obese and non-trained non-central obese subjects. The results showed that the 15 trained males with central obesity had average age 31.7±3.7 years and mean abdominal circumference 98.6±5.66 cm meanwhile the 15 untrained males without central obesity had mean age 29.4±6.4 years and mean abdominal circumference 80.27±7.05 cm. Mean HRR of the trained subjects was 55.6±10.6 and of the untrained subjects was 47.8 ±1.8. The non-tailed T test showed significant result in comparing the HRR between trained subjects and untrained subjects (P < 0.025). Abnormal HRR was found in 6.6% of the trained subjects and in 20% of the untrained subjects. Conclusion: Trained males with central obesity had a better HRR significantly than untrained males without central obesity; therefore, physical exercise played an important role in HRR.Keywords: heart rate recovery (HRR), central obesity, trained Abstrak: Pemulihan laju jantung (PLJ) merupakan prediktor kematian kardiovaskular pada orang dewasa dan dipengaruhi oleh sistem saraf otonom. Uniknya, atlet atau individu yang terlatih memiliki sistem saraf otonom yang lebih efektif dibandingkan dengan yang tidak terlatih. Jenis penelitian ialah deskriptif observasional dengan desain potong lintang. Subjek penelitian terdiri dari15 pria dewasa dengan obesitas sentral yang terlatih dan 15 pria dewasa dengan non-obesitas sentral yang tidak terlatih. Subjek dinyatakan terlatih bila memenuhi rekomendasi latihan fisik menurut WHO. Obesitas sentral diukur dengan meteran pada lingkar perut bila lebih dari 90 cm. Uji latih jantung (ULJ) menggunakan treadmill dengan protokol Bruce. Pemulihan laju jantung dinilai pada menit ke-2 fase pemulihan dan dikatakan abnormal bila PLJ <42 x/menit. Perbandingan antara PLJ pada subjek obes sentral yang terlatih dengan subjek non-obes sentral yang tidak terlatih diuji dengan uji-T tidak berpasangan. Hasil penelitian mendapatkan 15 subjek pria obes sentral yang terlatih dengan rerata usia 31,7±3,7 tahun, rerata lingkar perut 98,6±5,66cm dan 15 subjek pria non-obes sentral yang tidak terlatih dengan rerata usia 29,4±6,4 tahun, rerata lingkar perut 0,27±7,05cm. Rerata PLJ pada subjek obes sentral yang terlatih 55,6±10,6, dan rerata PLJ pada non-obes sentral yang tidak terlatih 47,8±1,8. Uji-T tidak berpasangan mendapatkan hasil bermakna untuk perbandingan antara PLJ pada subjek obes sentral yang terlatih dengan subjek non-obes sentral yang tidak terlatih (p<0,025). Didapatkan nilai abnormal PLJ 6,6% pada kelompok subjek obes sentral terlatih dan 20,0% pada kelompok subjek non-obes sentral tak terlatih. Simpulan: Subjek obes sentral yang terlatih memiliki PLJ yang lebih baik dibandingkan dengan subjek non-obes sentral yang tidak terlatih secara bermakna yang menunjukkan faktor latihan fisik berperan penting terhadap PLJ.Kata kunci: pemulihan laju jantung (PLJ), obesitas sentral, terlatih


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Qian-Qian Li ◽  
Guang-Xia Shi ◽  
Qian Xu ◽  
Jing Wang ◽  
Cun-Zhi Liu ◽  
...  

Acupuncture is a therapeutic technique and part of traditional Chinese medicine (TCM). Acupuncture has clinical efficacy on various autonomic nerve-related disorders, such as cardiovascular diseases, epilepsy, anxiety and nervousness, circadian rhythm disorders, polycystic ovary syndrome (PCOS) and subfertility. An increasing number of studies have demonstrated that acupuncture can control autonomic nerve system (ANS) functions including blood pressure, pupil size, skin conductance, skin temperature, muscle sympathetic nerve activities, heart rate and/or pulse rate, and heart rate variability. Emerging evidence indicates that acupuncture treatment not only activates distinct brain regions in different kinds of diseases caused by imbalance between the sympathetic and parasympathetic activities, but also modulates adaptive neurotransmitter in related brain regions to alleviate autonomic response. This review focused on the central mechanism of acupuncture in modulating various autonomic responses, which might provide neurobiological foundations for acupuncture effects.


Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1839 ◽  
Author(s):  
Mustafa Zelal Muallem ◽  
Thomas Jöns ◽  
Nadja Seidel ◽  
Jalid Sehouli ◽  
Yasser Diab ◽  
...  

The current understanding of radical hysterectomy is more centered on the uterus and little is discussed regarding the resection of the vaginal cuff and the paracolpium as an essential part of this procedure. The anatomic dissections of two fresh and 17 formalin-fixed female pelvis cadavers were utilized to understand and decipher the anatomy of the pelvic autonomic nerve system (PANS) and its connections to the surrounding anatomical structures, especially the paracolpium. The study mandates the recognition of the three-dimensional (3D) anatomic template of the parametrium and paracolpium and provides herewith an enhanced scope during a nerve-sparing radical hysterectomy procedure by precise description of the paracolpium and its close anatomical relationships to the components of the PANS. This enables the medical fraternity to distinguish between direct infiltration of the paracolpium, where the nerve sparing technique is no longer possible, and the affected lymph node in the paracolpium, where nerve sparing is still an option. This study gives rise to a tailored surgical option that allows for abandoning the resection of the paracolpium by FIGO stage IB1, where less than 2 cm vaginal vault resection is demanded.


1970 ◽  
Vol 6 (2) ◽  
pp. 77-83 ◽  
Author(s):  
Sangita Mithun ◽  
Noorzahan Begum ◽  
Sultana Ferdousi ◽  
Shelina Begum ◽  
Taskina Ali

Background: Physical inactivity and low resting heart rate variability (HRV) are associated with increased incidence of coronary heart disease. Heavy physical activity is associated with higher heart rate variability and reduces the risk of coronary heart disease Objective: To assess some time domain measures of HRV in order to compare Cardiac Autonomic Function between sedentary and heavy workers. Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University between 1st July 2008 to 30th June 2009 on 30 apparently healthy heavy workers aged 28-50 years from low socioeconomic condition (study group). For comparison 30 age, sex, BMI and socioeconomic status matched apparently healthy sedentary subjects (group A) were also studied. The study subjects were selected among rickshaw-pullers living in the slum areas nearby BSMMU, Dhaka and the controls were from fourth class employee of BSMMU, Dhaka. Heart Rate Variability were assessed by a Polygraph. Several time domain measures of HRV such as mean R-R interval, mean HR, SDNN, RMSSD were analyzed. For statistical analysis, Independent-Samples t-test, and Pearson’s correlation coefficient tests were done as applicable. Results: Resting mean heart rate (P<0.01), SDNN (P<0.01) and RMSSD (P<0.001) were significantly lower but mean R-R interval (P<0.001) was significantly higher in heavy workers than those of sedentary control. The mean R-R interval (P<0.05) showed significant positive correlation in heavy workers but significant negative correlation in sedentary workers with BMI. Conclusion: Cardiac autonomic nerve function status may be higher with parasympathetic dominance by increased physical activity. DOI: http://dx.doi.org/10.3329/jbsp.v6i2.9755 JBSP 2011 6(2): 77-83


2014 ◽  
Vol 57 ◽  
pp. 973-985
Author(s):  
Dong Hwan Kim ◽  
Il Gyu Jung ◽  
Sang Bok Kim

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