电刺激肾神经传入纤维对肾水钠钾排出的影响

本文探讨肾神经传入纤维对肾排泄功能的影响及其机制。在戊巴比妥钠麻醉猫中,切除双侧颈动脉窦神经、主动脉神经和迷走神经(SAD+VD),电刺激肾神经传入纤维使动脉血压明显升高,去神经肾的尿量,排钠量显著增多,排钾量和肾小球滤过率不变。神经完好肾的排钠量显著增加,尿量、排钾量和肾小球滤过率均无显著变化。在刺激肾神经传入纤维时,将动脉血压控制在对照期血压水平,两侧肾的尿量、排钠量、排钾量显著减少;神经完好肾的肾小球滤过率减少,而去神经肾的肾小球滤过率无显著改变。脊髓横断不能消除神经完好肾上述肾排泄功能的改变,但可消除去神经肾排泄功能的改变。这些结果表明,在SAD+VD猫中,控制动脉血压不变时,刺激肾神经传入纤维可使有神经肾和去神经肾排尿、排钠和排钾减少。在神经完好肾中这些反应可在脊髓水平完成。

EFFECTS OF STIMULATION OF RENAL AFFERENT NERVE ON RENAL EXCRETION OF WATER SODIUM AND POTASSIUM

The present study was designed to investigate the effect of stimulation of therenal afferent nerve (RAN) on renal excretory function and its mechanism. Inpentobarbital-anesthetized, sino-aortic denervated and vagotomized (SAD + VD)cats, stimulation of the RAN caused a significant rise in arterial pressure. In thedenervated kidney urine volume (Vu) and sodium excretion (U_(Na) V) were greatlyincreased, no changes in potassium excretion (U_K V) and glomerular filtrationrate (GFR) were observed. In the innervated kidney, U_(Na) V was greatly increa-sed, but Vu, U_K V and GFR were not different from those observed during thecontrol period. When arterial pressure was held constant at the control level,stimulation of the RAN reduced the Vu, U_K V of both the innervated and dener-vated kidneys and GFR in the innervated but not in the denervated kidney. Tran-section of spinal cord at C7 level did not abolish the changes in Vu, U_(Na) V, andU_K V in the innervated kidney, but completely eliminated the changes in the ex-cretory function in the denervated kidney. These data suggest that when arterialpressure is controlled, stimulation of the RAN causes a decrease in Vu, U_(Na) V,U_K V in SAD+VD cats and that these responses in the innervated kidney can beperformed at the spinal level.