Species differences between rabbits and cats in their respiratory responses to muscle thin-fiber afferents

Abstract

Electrical Stimulation (ES) of the muscle thin-fiber afferents causes respiratory facilitation during ES and is followed by respiratory suppression after the cessation of the stimulation in cats. To investigate this respiratory suppression, the experimental animals are needed in that this phenomenon is more clearly observed. In this study, it was examined whether this respiratory suppression could be induced in rabbits. At first, the protocol was established outlining the adequate conditions for ES in rabbits to induce respiratory facilitation during ES. This was established as 400 times a muscle twitch threshold set at 8.3 Hz for 30 sec. Despite these parameters, any reflex respiratory suppression after ES in rabbits were not observed. It seems reasonable to conclude, therefore, that the rabbit is not an animal species suitable for studies on reflex respiratory suppression.

標記線維の電気刺激(ES)は、ESの間に呼吸促進を起こし、ネコでは続いて刺激の中止後に呼吸抑制が起こる。この呼吸抑制を研究するためには、この現象がより明確な実験用動物が必要である。本研究ではこの呼吸抑制がウサギでも誘発出来るかどうかを調べた。まずES間に呼吸促進を誘発するためにウサギのESに十分な条件をまとめ、プロトコルを30秒間、3.3Hzで設定し、筋攣縮しきい値の400倍と決めた。これらのパラメータにも拘らず、ウサギではES後いかなる反射呼吸抑制も観察されなかった。従って結論としては、ウサギは反射呼吸抑制に関する研究には適した種属の動物ではないと考えたほうが良いと思われる。