ブラディキニンの降圧機序に関する研究 : 殊に交感神経活動の関与について

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概要

• 論文の詳細を見る

• Bradykinin (BK) has a potent hypotensive effect. To clarify the mechanism of this effect, changes in blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RNA) were observed in anesthetized rabbits. After the administration of 0.5 μg/kg, 1.0 μg/kg and 2.0 pg/kg ofBK into the femoral vein, two types of reversible decrease of BP were demonstrated. A slight and transient reduction of BP associated with an increase in RNA occured just after BK administration, and subsequently an intense and prolonged hypotensive reaction associated with a decrease in RNA was observed. The hypotensive effects of BK increased gradually with an augmentation of the dose. The latter phase of hypotension was abolished by vagotomy and the pretreatment with indomethacin. The same dose of BK were administered into the carotid artery and the femoral artery. An intense but brief hypotensive effect associated with a decrease in RNA occured just after BK administration. This reaction was also dose-dependent, although it was not abolished by vagotomy, but abolished by the indomethacin pretreatment. The hypotensive change induced by BK administration into the femoral artery was abolished by thoracic transection of spinal cord while that into the carotid artery was not abolished by this procedure. In addition, 1 μg/kg of BK was administered into cisterna magna. Hypotension associated with a decrease in RNA appeared and it was also abolished by the indomethacin pretreatment. From these resultes, it is suggested that BK has two different mechanisms in hypotensive effect, which consists of the direct effect on vascular smooth muscle and the suppressive effect on sympathetic nerve activity. The latter effect is considered to occur through an increase in afferent impulse of vagal nerves when administered intravenously, wheareas the afferent pathway may be the spinal cord when administered intra-arterially. Furthermore, it is postulated that the lattter effect is also induced by an acceleration of the prostaglandin synthesis.

• 神戸大学の論文

著者

• 佐々木 順子

  神戸大学医学部内科学第一講座

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• ブラディキニンの降圧機序に関する研究 : 殊に交感神経活動の関与について

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