Affiliation:
1. Department of Physiology , Institute of Medical Sciences, Banaras Hindu University , Varanasi , Uttar Pradesh , India
Abstract
Abstract
Objectives
The present work was designed to study the modulatory effects of algogen-induced vasosensory reflex responses on short-term heart rate variability (HRV) parameters in naïve and vagotomized rat models.
Methods
In this study, vasosensory reflex responses were elicited by instilling algogens (bradykinin/histamine), a component of inflammatory mediators into a local segment of medium-sized peripheral blood vessel (femoral artery) while a continuous electrocardiogram (ECG) was recorded. Short-term (5 min) ECG segments obtained from original recordings were examined in detail and relevant data of HRV parameters were pooled. Time domain and frequency domain analyses were performed using dedicated software (LabChart 8, AD Instruments®, Australia) and results were analyzed.
Results
Bradykinin-induced vasosensory reflexes caused significant alterations in both time domain and frequency domain HRV parameters as compared to the time-matched saline control group. Instillation of bradykinin caused a transient increase in NN interval, RMSSD, TSP, HF power (HFP) along with a decrease in the standard deviation of all normal NN intervals (SDNN), SDNN/RMSSD, LF power (LFP), LFP/HFP. Histamine produced a similar pattern of responses, but HRV alterations were less pronounced compared to those with bradykinin. Further analysis revealed that algogen-induced vasosensory reflex responses caused an increase in the parasympathetic influence on the heart accompanied by a decrease in sympathetic influence. In addition, HRV modulation by algogen-induced vasosensory reflexes was significantly attenuated in vagotomized rats, illustrating the principal role of vagus in the reflex HRV modulation.
Conclusions
The present study proposes a novel hypothesis regarding the cardio-protective role of inflammatory mediators during acute stress, by potentiating the vagal impact and attenuating the sympathetic impact on the heart.
Subject
Drug Discovery,Pharmacology,General Medicine,Physiology
Reference40 articles.
1. McCraty, R, Shaffer, F. Heart rate variability: new perspectives on physiological mechanisms, assessment of self-regulatory capacity and health risk. Glob Adv Health Med 2015;4:46–61. https://doi.org/10.7453/gahmj.2014.073.
2. Malik, M. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation 1996;93:1043–65.
3. Vaillancourt, DE, Newell, KM. Changing complexity in human behaviour and physiology through aging and disease. Neurobiol Aging 2002;23:1–11. https://doi.org/10.1016/s0197-4580(01)00247-0.
4. Bigger, JT, Fleiss, JL, Steinman, RC, Rolnitzky, LM, Kleiger, RE, Rottman, JN. Frequency domain measures of heart period variability and mortality after myocardial infarction. Circulation 1992;85:164–71. https://doi.org/10.1161/01.cir.85.1.164.
5. Saul, JP, Rea, RF, Eckberg, DL, Berger, RD, Cohen, RJ. Heart rate and muscle sympathetic nerve variability during reflex changes of autonomic activity. Am J Physiol 1990;258:H713–21. https://doi.org/10.1152/ajpheart.1990.258.3.h713.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献