Casadevall M, Panés J, Piqué J M, Bosch J, Terés J, Rodés J
Gastroenterology Department, Hospital Clinic, University of Barcelona, Spain.
Am J Physiol. 1992 Nov;263(5 Pt 1):G810-5. doi: 10.1152/ajpgi.1992.263.5.G810.
This study investigated the accuracy of laser-Doppler flowmetry (LDV) and reflectance spectrophotometry (RS) measurements as an index of blood flow in the gastric mucosa of the rat, in experimental conditions such as pharmacologically induced vasoconstriction, hypoxia, hyperoxia, and acute normovolemic anemia. Hydrogen gas clearance was used as a reference method. After vasopressin infusion, LDV signal and indexes of hemoglobin (IHb) and oxygen (ISO2) content in the gastric mucosa estimated by RS significantly decreased in parallel with the reduction of gastric mucosal blood flow (GMBF). Neither hypoxia (5% O2 administration) nor hyperoxia (100% O2) affected GMBF or LDV signal. However, both IHb and ISO2 significantly decreased or increased after hypoxia or hyperoxia, respectively. Acute normovolemic anemia induced a significant increase in GMBF, while LDV signal and ISO2 remained unchanged. IHb significantly decreased in linear relationship with the decrements in the hematocrit. It is concluded that 1) in pharmacologically induced GMBF changes, LDV and RS correlate with GMBF; 2) when changes in hemoglobin saturation are induced, LDV but not RS reflects GMBF; and 3) in acute normovolemic anemia, neither LDV nor RS reflects changes in GMBF.
本研究在诸如药物诱导的血管收缩、缺氧、高氧和急性正常血容量性贫血等实验条件下，调查了激光多普勒血流仪（LDV）和反射分光光度法（RS）测量作为大鼠胃黏膜血流指标的准确性。氢气清除率被用作参考方法。输注血管加压素后，LDV信号以及通过RS估计的胃黏膜血红蛋白（IHb）和氧（ISO2）含量指标与胃黏膜血流量（GMBF）的降低同时显著下降。缺氧（给予5% O2）和高氧（100% O2）均未影响GMBF或LDV信号。然而，缺氧或高氧后，IHb和ISO2分别显著降低或升高。急性正常血容量性贫血导致GMBF显著增加，而LDV信号和ISO2保持不变。IHb与血细胞比容的降低呈线性关系显著下降。得出的结论是：1）在药物诱导的GMBF变化中，LDV和RS与GMBF相关；2）当诱导血红蛋白饱和度变化时，LDV而非RS反映GMBF；3）在急性正常血容量性贫血中，LDV和RS均未反映GMBF的变化。
