抄録
Hypotension is one of the most common complications in dental practice. Some stressors (eg, pain, anxiety, tension) are considered to be the cause. Trigeminal stimulation plays an important role and baroreflex seems to participate in this complication. The effect of electrical stimulation of both the aortic depressor nerve (ADN) and infraorbital nerve (ION) on blood pressure and renal sympathetic nervous activities (RSNA) was examined in anesthetized rabbits. Under uretane and α-chloralose anesthesia, animals were ventilated artificially. Arterial pressure was monitored from the femoral artery. Bipolar electrodes were placed to stimulate ADN and ION. Electrical stimulation of the ION was performed by square impulses with a duration of 0.25 ms. The frequencies of stimuli were 5 and 25 Hz, and the strengths were 10 V. Stimulation of the ADN was 0.25 ms in duration, 10 V in strength and 25 Hz in frequency. The renal sympathetic nerve was exposed and isolated. RSNA was recorded from an intact branch of the renal nerve placed on bipolar recording electrodes.RSNA decreased when blood pressure fell after stimulation of ADN and ION. Hypotension and decrease of RSNA evoked with simultaneous stimuli of the ADN and ION lasted grater than that evoked with individual stimulation of the ADN or ION. This result suggested that simultaneous stimulaion of aoritc and trigeminal nerve lowered blood pressure further and it contributed to the occurrence of hypotension in dental practice. [Jpn J Physiol 54 Suppl:S198 (2004)]
