肾动脉内注射缓激肽对麻醉家兔肾传入神经放电的双相激活(英文)

BIPHASIC ACTIVATION OF RENAL AFFERENT BY INTRARENAL ARTERY INJECTION OF BRADYKININ IN ANESTHETIZED RABBITS

在48只麻醉家兔,应用记录肾传入神经多单位和单位放电方法,观察了肾动脉内注射缓激肽(bradykinin,BK,50g/kg)对肾传入神经活动(ARNA)的影响。结果表明:(1)肾动脉内应用BK引起ARNA双相激活。ARNA激活的初发相在肾动脉注射BK后迅速出现,延迟相则见于注射后7min左右,且延迟相的激活作用大于初发相。(2)静脉内预先注射前列环素合成阻断剂Indomethacin(Indo,50mg/kg),可部分阻断BK引起的ARNA延迟相的激活,对初发相的激活并无影响;(3)静脉内预先注射NO合酶抑制剂LNAME(300mg/kg),可完全阻断BK引起的ARNA延迟相的激活,而对初发相仅有部分阻断作用。本实验提示:肾内应用缓激肽所致ARNA初发相的激活,可归因于BK的直接作用及其所诱发NO的释放,延迟相的激活主要在于BK引起前列环素和NO释放的结果。

The effect of intrarenal artery injection of bradykinin (BK, 5 0 μg/kg) on multi and single unit recordings of afferent renal nerve activity (ARNA) was examined in anesthetized 48 rabbits. The results obtained are as follows. (1) There were two phases of increase in ARNA following intrarenal BK. The early phase occurred immediately while the delayed phase made its appearance about 7 min later. The degree of increase in ARNA of the delayed phase induced by intrarenal BK was more prominent than that in the early phase. BP was actually unaltered following intrarenal BK. (2) By pretreatment with indomethacin (Indo, 5 0 mg/kg), the delayed phase of increase in ARNA induced by intrarenal BK was attenuated, while the early phase was not affected. (3) Pretreatment with L NAME (30 mg/kg) led the delayed phase to be blocked completely while the early phase was partially decreased. From the above mentioned observations, it is concluded that intrarenal BK induces a significant increase in ARNA in two phases. The early phase may be due to the direct action of BK and partially due to the NO action, while the delayed phase may be attributed to the action of released prostaglandin and NO as a result of intrarenal BK.