Takishita S, Muratani H, Kawazoe N, Tozawa M, Kimura Y, Fukiyama K
Third Department of Internal Medicine, School of Medicine, University of the Ryukyus, Okinawa, Japan.
Blood Press Suppl. 1992;3:53-9.
To examine acute effects of manidipine hydrochloride, a new calcium antagonist, on renal blood flow (RBF) in spontaneously hypertensive rats, we recorded changes in RBF as the Doppler shift and a neurogram of renal sympathetic nerve activity (RSNA) simultaneously in a conscious and unrestrained state. An intravenous infusion of manidipine did not decrease RBF until mean arterial pressure (MAP) fell by 20 +/- 1 mmHg and RSNA increased by 98 +/- 18%. At the nadir of RBF (-25 +/- 2%, MAP: -31 +/- 2 mmHg, RSNA: +154 +/- 25%), percent increase in RSNA significantly correlated with percent decrease in RBF (r = -0.802, p < 0.02). On the other hand, the infusion of sodium nitroprusside did not decrease RBF significantly even at a nadir of MAP (-35 +/- 2 mmHg). Air jet stress increased both MAP and RSNA associated with a decrease in RBF. Responses of MAP and RBF were blunted after manidipine infusion while the stress evoked a similar degree of enhancement of RSNA to that of the control trial. Although manidipine may be less effective than nitroprusside in maintaining RBF during abrupt reductions of MAP, the results of this study suggest that antihypertensive treatment with manidipine may be clinically beneficial in maintaining RBF both at rest and during psychologically stressful conditions.
为研究新型钙拮抗剂盐酸马尼地平对自发性高血压大鼠肾血流量（RBF）的急性影响，我们在清醒且不受限制的状态下，同时记录了作为多普勒频移的RBF变化以及肾交感神经活动（RSNA）的神经图。静脉输注马尼地平直至平均动脉压（MAP）下降20±1 mmHg且RSNA增加98±18%时，RBF才会降低。在RBF最低点时（-25±2%，MAP：-31±2 mmHg，RSNA：+154±25%），RSNA的增加百分比与RBF的降低百分比显著相关（r = -0.802，p < 0.02）。另一方面，即使在MAP最低点（-35±2 mmHg）时，静脉输注硝普钠也不会使RBF显著降低。喷气应激会使MAP和RSNA升高，同时伴有RBF降低。输注马尼地平后，MAP和RBF的反应减弱，而应激诱发的RSNA增强程度与对照试验相似。尽管在MAP突然降低期间，马尼地平在维持RBF方面可能不如硝普钠有效，但本研究结果表明，用马尼地平进行抗高血压治疗在静息状态和心理应激状态下维持RBF方面可能具有临床益处。
