HEPARINASE TREATMENT SUGGESTS A ROLE FOR THE ENDOTHELIAL-CELL GLYCOCALYX IN REGULATION OF CAPILLARY HEMATOCRIT
HEPARINASE TREATMENT SUGGESTS A ROLE FOR THE ENDOTHELIAL-CELL GLYCOCALYX IN REGULATION OF CAPILLARY HEMATOCRIT
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DOI：
10.1152/ajpheart.1990.258.3.h647
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发表时间：
1990-03-01
影响因子：
--
通讯作者：
DULING, BR
中科院分区：
文献类型：
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作者：
DESJARDINS, C;DULING, BR
生理刺激诱导骨骼肌毛细血管内红细胞数量的快速和无法解释的增加。我们假设毛细血管内红细胞数量的这种变化可能是由于血液中的一种或多种成分与毛细血管腔表面之间的不确定的相互作用。这一命题进行了测试，在原位微灌注的毛细血管与酶直接对大分子可能表达的内皮细胞表面。毛细管内红细胞的瞬时分数体积（管血细胞比容）被用作毛细管对酶微灌注的响应的指标。用酶载体（0.25%白蛋白-林格溶液）灌注5 - 8分钟，毛细管红细胞压积未发生显著变化。用含肝素酶的溶液灌注可使试管红细胞压积至少提高两倍（P < 0.05），而红细胞流速无显著变化。热变性肝素酶和其他酶如神经氨酸酶、透明质酸酶、木瓜蛋白酶、链霉蛋白酶E和梭菌蛋白酶对试管红细胞压积无明显影响（P > 0.05）。酶处理后，应用腺苷（10-4 M）或氧引起供应灌注毛细血管单位的小动脉的活跃血管反应，但未观察到管红细胞压积的通常变化。因此，肝素酶治疗导致毛细血管血细胞比容持续升高，并使血管扩张变化与毛细血管中红细胞分布之间的典型关系分离。这些发现表明，改变毛细血管内红细胞数量的生理刺激可能通过改变血浆与毛细血管腔表面上的一种或多种组分之间的相互作用来起作用。
Physiological stimuli induce rapid and unexplained increases in the number of red blood cells within capillaries of skeletal muscle. We hypothesized that such alterations in intracapillary red cell numbers might be due to an undefined interaction between one or more components of blood and the luminal surface of the capillary. This proposition was tested by in situ microperfusion of capillaries with enzymes directed against macromolecules likely to be expressed on the surface of endothelial cells. The instantaneous fractional volume of red blood cells within a capillary (tube hematocrit) was used as an index of a capillary''s response to enzyme microperfusion. Five to 8 min of perfusion with enzyme vehicle (0.25% albumin-Ringer solution) produced no significant alteration in capillary tube hematocrit. Perfusion with solutions containing heparinase raised the tube hematocrit at least twofold (P < 0.05) without a significant change in red cell velocity. Heat-denatured heparinase and other enzymes such as neuraminidase, hyaluronidase, papain, pronase E, and clostripain had no detectable effect on the tube hematocrit (P > 0.05). After enzyme treatment, appication of adneosine (10-4 M) or oxygen caused brisk vasomotor responses in arterioles feeding perfused capillary units, but the usual changes in the tube hematocrit were not observed. Thus heparinase treatment results in a sustained elevation in the capillary tube hematocrit and a dissociation of the typical relationship between vasomotor changes and red cell distribution in capillaries. These findings suggest that physiological stimuli which alter the number of red blood cells within capillaries may operate by modifying interactions between plasma and one or more components on the luminal surface of capillaries.