Sex differences in heart rate and heart rate variability in rats: Implications for translational research
Open Access
- 24 March 2023
- journal article
- research article
- Published by Frontiers Media SA in Frontiers in Physiology
Abstract
The present study aimed to investigate sex differences in measures of cardiac chronotropy and heart rate variability (HRV) in 132 young adult wild-type Groningen rats (n = 45 females). Electrocardiographic signals were recorded for 48 hours in freely moving rats to quantify heart rate (HR) and inter-beat interval (IBI) as measures of cardiac chronotropy, and time- and frequency-domain HRV parameters as physiological readouts of cardiac vagal modulation. Females showed greater vagally-mediated HRV despite having higher HR and shorter IBI than males during undisturbed conditions. Such differences were evident (i) at any given level of HRV, and (ii) both during the 12-h light/inactive and 12-h dark/active phase of the daily cycle. These findings replicate the paradoxical cardiac chronotropic control reported by human meta-analytic findings, since one would expect greater vagally-mediated HRV to be associated with lower HR and longer IBI. Lastly, the association between some HRV measures and HR was stronger in female than male rats. Overall, the current study in young adult rats provides data illustrating a sex-dependent association between vagally-mediated HRV and indexes of cardiac chronotropy. The current results (i) are in line with human findings, (ii) suggest to always consider biological sex in the analysis and interpretation of HRV data in rats, and (iii) warrant the use of rats for investigating the neuro-hormonal basis and temporal evolution of the impact of sex on the association between vagally-mediated HRV and cardiac chronotropy, which could inform the human condition.Keywords
This publication has 41 references indexed in Scilit:
- Vagal Withdrawal and Susceptibility to Cardiac Arrhythmias in Rats with High Trait AggressivenessPLOS ONE, 2013
- Low frequency power of heart rate variability reflects baroreflex function, not cardiac sympathetic innervationClinical Autonomic Research, 2011
- Fractal properties of human heart period variability: physiological and methodological implicationsJournal Of Physiology-London, 2009
- Regression Analysis Between Heart Rate Variability and Baroreflex‐Related Vagus Nerve Activity in RatsJournal of Cardiovascular Electrophysiology, 2005
- Electrode Positioning for Reliable Telemetry ECG Recordings During Social Stress in Unrestrained RatsPhysiology & Behavior, 1996
- SEX DIFFERENCES IN THE PARASYMPATHETIC NERVE CONTROL OF RAT HEARTClinical and Experimental Pharmacology and Physiology, 1994
- Spectral analysis of blood pressure and heart rate in conscious rats: effects of autonomic blockersJournal of the Autonomic Nervous System, 1990
- Sexually dimorphic development of cholinergic enzymes in the rat septohippocampal systemDevelopmental Brain Research, 1987
- Changes in Heart Period, Heart‐Period Variability, and a Spectral Analysis Estimate of Respiratory Sinus Arrhythmia in Response to Pharmacological Manipulations of the Baroreceptor Reflex in CatsPsychophysiology, 1985
- Tests for comparing elements of a correlation matrix.Psychological Bulletin, 1980