MICROVASCULAR HEMATOCRIT AND RED-CELL FLUX IN RAT CREMASTER MUSCLE
MICROVASCULAR HEMATOCRIT AND RED-CELL FLUX IN RAT CREMASTER MUSCLE
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DOI:
10.1152/ajpheart.1987.252.1.h211
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发表时间:
1987-01-01
影响因子:
--
通讯作者:
LIPOWSKY, HH
中科院分区:
文献类型:
--
作者:
HOUSE, SD;LIPOWSKY, HH
The arteriovenous distributions of volumetric flow (Q), microvessel hematocrit (Hctmicro), and estimates of red cell volumetric flux (QRBC) were obtained under control conditions in rat cremaster muscle. The results demonstrate a monotonic fall in the ratio of Hctmicro/Hctsystemic from 0.86 in 70-microns arterioles to 0.48 in capillaries followed by a subsequent rise to 0.79 in 98-microns venules. To assess the roles of Hctmicro and Q in red blood cell delivery following a period of reduced oxygen transport, tissue ischemia was produced by occluding the first order arteriole. During the occlusion, arteriolar and large venular hematocrits fell 15–30%, whereas small venular hematocrits increased 24%. After release of the occlusion, a reactive hyperemia ensued with Q, QRBC, and QHctmicro increasing significantly above control values in arterioles, capillaries, and venules. All Hctmicro returned to their control values within 10 s following resumption of flow. Based on the relationship between blood viscosity and Hctmicro, at low shear rate, these transient alterations in Hctmicro were estimated to have a profound effect on blood viscosity, and hence the resistance to blood flow. Such changes may affect recovery from an ischemic episode, although not adversely affecting the oxygen-carrying capacity of blood and convective transport of oxygen.