Gunnarsson U, Hjelmqvist H, Rundgren M
Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
Shock. 1994 Jul;2(1):60-7. doi: 10.1097/00024382-199407000-00012.
The influence of separate and combined intracerebroventricular (ICV) infusions of hypertonic (.5 M) NaCl (HTNa) at .02 mL min-1 and angiotensin II (ANG II) at 1 pmol kg-1 min-1 on tolerance to hemorrhage, accompanying systemic hemodynamic changes, and regional blood flow was studied in adult conscious sheep. Corresponding measurements during ICV .9% NaCl served as controls. The hemorrhage volume needed to lower the blood pressure to about 50 mmHg was significantly larger during treatment with HTNa and HTNa/ANG II (27.8 +/- 2.2 and 28.3 +/- 2.5 mL kg-1, respectively; p < .001; about 45% of estimated blood volume) as well as during ANG II (20.1 +/- 1.3 mL kg-1; p < .01) compared to controls (15.1 +/- .7 mL kg-1; about 25% of estimated blood volume). In spite of a larger hemorrhage volume, the lowering of the cardiac output was not accentuated, and its subsequent recovery was not impaired during ICV infusion of HTNa or HTNa/ANG II. Similarly, the posthemorrhage restoration of the systemic blood pressure was not negatively affected by the more pronounced hypovolemia induced during the ICV treatments compared to controls. In contrast to ANG II, HTNa infusion, alone or in combination with ANG II, was accompanied by a significantly lower renal blood flow, and a higher renovascular resistance, during the posthemorrhage period. The femoral blood flow was maintained or even slightly elevated after hemorrhage in all experiments. The integrated results of the study imply differentiated hemodynamic effects of centrally administered HTNa and ANG II.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了成年清醒绵羊在分别及联合脑室内（ICV）输注0.02 mL min⁻¹的高渗（0.5 M）NaCl（HTNa）和1 pmol kg⁻¹ min⁻¹的血管紧张素II（ANG II）时，对出血耐受性、伴随的全身血流动力学变化及局部血流的影响。ICV输注0.9% NaCl时的相应测量作为对照。与对照组（15.1±0.7 mL kg⁻¹；约占估计血容量的25%）相比，在HTNa和HTNa/ANG II治疗期间（分别为27.8±2.2和28.3±2.5 mL kg⁻¹；p<0.001；约占估计血容量的45%）以及ANG II治疗期间（20.1±1.3 mL kg⁻¹；p<0.01），将血压降至约50 mmHg所需的出血量显著更大。尽管出血量更大，但在ICV输注HTNa或HTNa/ANG II期间，心输出量的降低并未加剧，其随后的恢复也未受损。同样，与对照组相比，ICV治疗期间诱导的更明显的血容量减少并未对出血后全身血压的恢复产生负面影响。与ANG II不同，在出血后期间，单独或与ANG II联合输注HTNa时，肾血流量显著降低，肾血管阻力更高。在所有实验中，出血后股血流量维持不变甚至略有升高。该研究的综合结果表明，中枢给予HTNa和ANG II具有不同的血流动力学效应。（摘要截断于250字）
