Nana Sato Hashizume, Yoichiro Kitajima, Ryoji Ide, Eishi Nakamura, Chikako Saiki
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引用次数: 0
Abstract
We examined respiratory sinus arrhythmia (RSA) and possible interaction with respiratory frequency (fR) and heart rate (HR) in spontaneously breathing, unanesthetized newborn Wistar rats (2- to 5-day-old; n = 54) and the adult rats (8-week-old; n = 34). Instantaneous heart rate (inst-HR) was calculated as the reciprocal of the inter-beat-interval. For each breath, RSA was determined as the difference between the maximum and minimum inst-HR value. The absolute RSA or RSA% (RSA per HR) were calculated as the average RSA of 10 consecutive breaths. RSA (or RSA%) in the newborn rats was significantly lower than that in the adult rats. Correlation coefficient between RSA (or RSA%) and 1/fR or HR/fR, but not HR, was significant in newborn rats, whereas only that between RSA (or RSA%) and HR was significant in adult rats. The power spectrum density of heartbeat fluctuation was detectable in both age groups. The present findings suggest that RSA exists and could be influenced by fR, rather than HR, in newborn rats.
期刊介绍:
Respiratory Physiology & Neurobiology (RESPNB) publishes original articles and invited reviews concerning physiology and pathophysiology of respiration in its broadest sense.
Although a special focus is on topics in neurobiology, high quality papers in respiratory molecular and cellular biology are also welcome, as are high-quality papers in traditional areas, such as:
-Mechanics of breathing-
Gas exchange and acid-base balance-
Respiration at rest and exercise-
Respiration in unusual conditions, like high or low pressure or changes of temperature, low ambient oxygen-
Embryonic and adult respiration-
Comparative respiratory physiology.
Papers on clinical aspects, original methods, as well as theoretical papers are also considered as long as they foster the understanding of respiratory physiology and pathophysiology.