电刺激肾神经传入纤维对肾水钠钾排出的影响

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

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。

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.