Katzberg R W, Schulman G, Meggs L G, Caldicott W J, Damiano M M, Hollenberg N K
Invest Radiol. 1983 Jan-Feb;18(1):74-80. doi: 10.1097/00004424-198301000-00015.
Radiographic contrast media (CM) (meglumine/sodium diatrizoate-76%; 1650 mOsm/kg) and other hypertonic solutions induce renal vasoconstriction by an unknown mechanism. In anesthetized dogs, renal blood flow (RBF) was measured with an electromagnetic flowmeter and filtration fraction (FF) and glomerular filtration rate (GFR) by the renal extraction of technetium-99m tin chelate. Ureteral pressure (UP) and wedged renal venous pressure (VP) were measured as indices of intrarenal pressure. Measurements of renal length (L), along with pressures, made it possible to examine the compliance of the system. A 4-cc intrarenal bolus of CM caused a 59% reduction in GFR (control: 0.63 +/- 0.04 to 0.26 +/- 0.04 ml/min X g, mean +/- SEM), in association with a 23% reduction in RBF (control: 3.10 +/- 0.11 to 2.39 +/- 0.26 ml/min X g) and a 44% decrease in FF (control: 0.32 +/- 0.01 to 0.18 +/- 0.03). These responses were compared with a 3-microgram intrarenal bolus of norepinephrine (NOREPI) which resulted in a 79.0 +/- 7.5% reduction in RBF, 68.3 +/- 7.3% reduction in GFR and 42.6 +/- 15.6% increase in FF. The NOREPI-induced vasoconstriction caused transient decreases in renal L, UP, and VP, whereas the CM-induced decrease in renal blood flow was associated with increases in these parameters. In studies employing ureteral occlusion to elevate intrarenal pressure, the magnitude (area, cm2) of the CM-induced decrease in renal perfusion was accentuated with increased UP (r = 0.79, n = 24, P less than 0.001). The CM-induced increase in renal L, UP, and VP must reflect osmotic forces and an increase in intrarenal pressure. The decreases in FF and GFR probably reflect Starling forces in the glomerular capillaries, with osmotic transients dominating. The results suggest a mechanical mechanism for the CM-induced decrease in RBF.
放射造影剂（CM）（葡甲胺/泛影葡胺钠 - 76%；1650毫渗摩尔/千克）和其他高渗溶液通过未知机制诱导肾血管收缩。在麻醉犬中，用电磁流量计测量肾血流量（RBF），通过肾提取锝 - 99m锡螯合物测量滤过分数（FF）和肾小球滤过率（GFR）。测量输尿管压力（UP）和楔入式肾静脉压力（VP）作为肾内压力指标。测量肾长度（L）以及压力，使得能够检查该系统的顺应性。4毫升肾内注射CM导致GFR降低59%（对照：0.63±0.04至0.26±0.04毫升/分钟×克，平均值±标准误），同时RBF降低23%（对照：3.10±0.11至2.39±0.26毫升/分钟×克），FF降低44%（对照：0.32±0.01至0.18±0.03）。将这些反应与3微克肾内注射去甲肾上腺素（NOREPI）的反应进行比较，后者导致RBF降低79.0±7.5%，GFR降低68.3±7.3%，FF增加42.6±15.6%。NOREPI诱导的血管收缩导致肾L、UP和VP短暂降低，而CM诱导的肾血流量降低与这些参数增加有关。在采用输尿管阻塞以升高肾内压力的研究中，随着UP增加，CM诱导的肾灌注降低幅度（面积，平方厘米）增大（r = 0.79，n = 24，P < 0.001）。CM诱导的肾L、UP和VP增加必定反映了渗透力和肾内压力升高。FF和GFR降低可能反映了肾小球毛细血管中的斯塔林力，其中渗透瞬变起主导作用。结果提示了CM诱导RBF降低的一种机械机制。
