Lombard J H, Frisbee J C, Greene A S, Hudetz A G, Roman R J, Tonellato P J
Department of Physiology, Medical College of Wisconsin, Milwaukee, 53226, USA.
Am J Physiol Heart Circ Physiol. 2000 Nov;279(5):H2295-302. doi: 10.1152/ajpheart.2000.279.5.H2295.
This study determined whether arteriolar blood flow, capillary red blood cell (RBC) velocity, capillary hematocrit (Hct(cap)), and tissue PO(2) are altered in cremaster muscles of rats with chronic reduced renal mass hypertension (RRM-HT) relative to normotensive rats on high- or low-salt (NT-HS vs. NT-LS) diet. The blood flow in first- through third-order arterioles was not different between NT and HT rats, either at rest or during maximal relaxation of the vessels with 10(-4) M adenosine. Capillary RBC velocity was similar between the groups at rest but was elevated in RRM-HT and NT-HS rats during adenosine superfusion. Hct(cap) was reduced at rest in RRM-HT and NT-HS rats compared with NT-LS and was reduced in RRM-HT rats during adenosine-induced dilation. Tissue PO(2) was reduced in RRM-HT and NT-HS rats compared with NT-LS rats during control conditions and was lower in RRM-HT than in NT-LS rats during adenosine-induced dilation. These results indicate that both RRM-HT and chronic exposure of normotensive rats to a high-salt diet lead to reduced tissue oxygenation, despite the maintenance of normal arteriolar blood flow.
本研究确定了相对于高盐或低盐（正常血压高盐组与正常血压低盐组）饮食的正常血压大鼠，慢性肾质量减少性高血压（RRM-HT）大鼠提睾肌的小动脉血流、毛细血管红细胞（RBC）速度、毛细血管血细胞比容（Hct(cap)）和组织PO₂是否发生改变。在静息状态或用10⁻⁴ M腺苷使血管最大程度舒张时，正常血压大鼠和高血压大鼠的一级至三级小动脉血流均无差异。静息时各组间毛细血管RBC速度相似，但在腺苷灌注期间，RRM-HT大鼠和正常血压高盐组大鼠的该速度升高。与正常血压低盐组相比，RRM-HT大鼠和正常血压高盐组大鼠静息时Hct(cap)降低，且在腺苷诱导的扩张过程中，RRM-HT大鼠的Hct(cap)降低。在对照条件下，与正常血压低盐组大鼠相比，RRM-HT大鼠和正常血压高盐组大鼠的组织PO₂降低，且在腺苷诱导的扩张过程中，RRM-HT大鼠的组织PO₂低于正常血压低盐组大鼠。这些结果表明，尽管小动脉血流维持正常，但RRM-HT和正常血压大鼠长期暴露于高盐饮食均会导致组织氧合降低。
