兔脊髓α受体对血量扩张引起肾交感神经活动抑制和促钠排泄的作用

ROLE OF SPINAL α ADRENOCEPTOR IN THE INHIBITION OF RENAL SYMPATHETIC NERVE ACTIVITY AND NATRIURESIS INDUCED BY BLOOD VOLUME EXPANSION IN RABBITS

在窦主动脉去神经麻醉兔观察阻断脊髓α受体对血量扩张引起肾交感神经活动（RSNA）抑制和促钠排泄反应的影响。兔脊髓蛛网膜下腔注射a肾上腺素能受体阻断剂酚妥拉明与人工脑脊液后，血量扩张引起RSNA抑制分别为（－25．4±5．4）％与（－42．5±5.2）％（P＜0.05）；兔脊髓蛛网膜下腔注射α1受体阻断剂哌唑嗪与人工脑脊液后血量扩张引起RSNA抑制分别为（－29．3±6.1）％与（－42．5±5.2）％（P＜005）。结果表明，阻断脊髓α受体或α1受体均可减弱血量扩张引起RSNA抑制。脊髓注射哌唑嗪后血量扩张引起促钠排泄与利尿反应也显著减弱（P＜005）。

The effect of spinal a adrenoceptor blockage on the inhibition of renal sympathetic nerve activity (RSNA ) and natriuresis induced by blood volume expansion was investigated in anesthetized and bilateral sinoaortic denervated rabbits. In the groups of rabbits with intrathecal injection of α-adrenoceptor blocker phentolamine or artificial cerebrospinal fluid the inhibition of RSNA induced by bl0od v0lume expansion were (- 25.4 t 5 .4) % and (- 42.5 i 5.2) % respectively (P < 0.05). In the groups of rahbits with intrathecal injection of α1 adtenoceptor blocker prazosin or artificial cerebrospinal fluid the inhibition of RSNA induced by blood volume expansion were (- 29.3 ±6.1 ) % and (-42.5 ±5.2) % respectively (P<0.05 ). These results suggested that both spinal α and α1 adrenceptor blockage attenuated the inhibition of RSNA induced by blood volume expansion. The spinal al adrenceptor blockage with intrathecal injection of prazosin also attenuated signiticantly the natriuresis and diuresis induced by bl0od volume expansion (P < 0.05).