Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

4.5K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.5K
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response01:15

Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response

356
Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
356
Pulse rhythm01:30

Pulse rhythm

1.3K
Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac...
1.3K
Disturbances in Heart Rhythm01:29

Disturbances in Heart Rhythm

2.6K
Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
2.6K
ECG Interpretation of Rhythms01:24

ECG Interpretation of Rhythms

13.1K
An electrocardiogram (ECG)graphically represents the heart's electrical activity on ECG paper or a monitor.
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage....
13.1K
Electrophysiology of Normal Cardiac Rhythm01:19

Electrophysiology of Normal Cardiac Rhythm

8.8K
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase...
8.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Comparing in-person and remote consent of people with dementia into a primary care-based cluster randomised controlled trial: lessons from the Dementia PersonAlised Care Team (D-PACT) feasibility study.

BMC medical research methodology·2025
Same author

Recurrent acute otitis media: a survey of current management in England.

The Journal of laryngology and otology·2021
Same author

Incidence and risk factors for feline lymphoma in UK primary-care practice.

The Journal of small animal practice·2020
Same author

Transverse sectioning in the evaluation of skin biopsy specimens from alopecic dogs.

The Journal of small animal practice·2020
Same author

A systematic review of the quality and scope of economic evaluations in child oral health research.

BMC oral health·2019
Same author

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients.

Space science reviews·2018

Related Experiment Video

Updated: Jan 21, 2026

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents
05:46

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

Published on: January 24, 2013

22.0K

Continuous Free Cortisol Profiles-Circadian Rhythms in Healthy Men.

R C Bhake1,2, V Kluckner3, H Stassen3

  • 1University Hospitals Leicester National Health Service Trust, Leicester, United Kingdom.

The Journal of Clinical Endocrinology and Metabolism
|July 30, 2019
PubMed
Summary
This summary is machine-generated.

This study monitored subcutaneous free cortisol in healthy men for up to 72 hours, revealing consistent circadian rhythms despite daily activities. This research enables long-term ambulatory monitoring of cortisol profiles.

More Related Videos

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila
18:08

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

Published on: September 28, 2010

48.2K
In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.4K

Related Experiment Videos

Last Updated: Jan 21, 2026

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents
05:46

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

Published on: January 24, 2013

22.0K
Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila
18:08

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

Published on: September 28, 2010

48.2K
In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.4K

Area of Science:

  • Endocrinology
  • Chronobiology
  • Physiology

Background:

  • The pituitary-adrenal axis is a key model for circadian rhythms.
  • Portable microdialysis devices allow for continuous monitoring of free cortisol in free-living individuals.

Purpose of the Study:

  • To evaluate free cortisol profiles using microdialysis in individuals conducting daily activities.
  • To assess the consistency of circadian cortisol rhythms over extended periods.

Main Methods:

  • Healthy male volunteers participated in two experiments.
  • Subcutaneous (SC) free cortisol was measured at 10-minute intervals for 24 hours and at 20-minute intervals for 72 hours using microdialysis.

Main Results:

  • Circadian rhythms were observed in both serum total and SC free cortisol, with peaks around waking and troughs during sleep.
  • SC free cortisol rhythms remained consistent over 72 hours in free-living individuals.
  • Cortisol levels increased after lunch and were lowest after lights off.

Conclusions:

  • This study is the first to report up to three consecutive 24-hour measurements of SC free cortisol in healthy individuals.
  • The findings pave the way for ambulatory monitoring of free cortisol profiles for up to 72 hours.
  • This monitoring is valuable for studying diseases involving the hypothalamic-pituitary-adrenal axis.