Kirchner K A, Crosby B A, Patel A R, Granger J P
Department of Medicine and Physiology, University of Mississippi Medical Center, Jackson 39216-4505, USA.
J Am Soc Nephrol. 1995 Feb;5(8):1567-72. doi: 10.1681/ASN.V581567.
L-Arginine normalizes pressure natriuresis in Dahl salt-sensitive (DS) rats. The nephron segments responsible for improvement in sodium chloride handling during L-arginine administration are unknown. Micropuncture techniques were used to examine fluid and chloride transport along superficial nephron segments in DS rats maintained on an 8% sodium diet and given L-arginine or vehicle ip for 3 wk. Renal perfusion pressure in vehicle-treated DS rats was reduced to that of L-arginine-treated DS rats with an aortic snare. Dahl salt-resistant (DR) rats receiving vehicle were examined for comparison. In agreement with previous studies, urinary sodium chloride excretion was greater (P < 0.05) in L-arginine DS rats than in vehicle DS rats and not different from DR rats at equivalent renal perfusion pressures. Whole-kidney and single-nephron GFR were not different (P = not significant) among groups. Fractional proximal tubule chloride and fluid reabsorption was not different among groups. Fractional loop chloride reabsorption was greater in vehicle-treated DS rats than in DR rats (58.5 +/- 1.5 versus 46.6 +/- 1.7%; P < 0.05), confirming the enhanced chloride reabsorption at this location in DS rats previously reported. Fractional loop chloride reabsorption was identical in vehicle- and L-arginine-treated DS rats (58.4 +/- 1.4 versus 58.9 +/- 3.9%; P = not significant). Fractional loop fluid reabsorption was not different among groups. Fractional distal fluid and chloride reabsorption was not different between DS rat groups.(ABSTRACT TRUNCATED AT 250 WORDS)
L-精氨酸可使 Dahl 盐敏感（DS）大鼠的压力利尿恢复正常。在给予 L-精氨酸期间，负责改善氯化钠处理的肾单位节段尚不清楚。采用微穿刺技术，检查了维持在 8%钠饮食并腹腔注射 L-精氨酸或赋形剂 3 周的 DS 大鼠浅表肾单位节段的液体和氯离子转运情况。用主动脉夹将接受赋形剂治疗的 DS 大鼠的肾灌注压降低至接受 L-精氨酸治疗的 DS 大鼠的水平。检查接受赋形剂的 Dahl 盐抵抗（DR）大鼠作为对照。与先前的研究一致，在相同的肾灌注压下，L-精氨酸处理的 DS 大鼠的尿氯化钠排泄量高于（P < 0.05）赋形剂处理的 DS 大鼠，且与 DR 大鼠无差异。各组间全肾和单肾单位肾小球滤过率无差异（P = 无显著性）。各组间近端小管氯离子和液体重吸收分数无差异。赋形剂处理的 DS 大鼠的髓袢氯离子重吸收分数高于 DR 大鼠（58.5±1.5 对 46.6±1.7%；P < 0.05），证实了先前报道的 DS 大鼠该部位氯离子重吸收增强。赋形剂处理和 L-精氨酸处理的 DS 大鼠的髓袢氯离子重吸收分数相同（58.4±1.4 对 58.9±3.9%；P = 无显著性）。各组间髓袢液体重吸收分数无差异。DS 大鼠组间远端液体和氯离子重吸收分数无差异。（摘要截断于 250 字）
