Horowitz M, Bar-Ilan D H, Samueloff S
Comp Biochem Physiol A Comp Physiol. 1985;81(1):103-7. doi: 10.1016/0300-9629(85)90274-9.
Cardiac output (CO) and its distribution were studied in dehydrated (37 degrees C) anesthetized (Na thiopentone) rats prior to and following heat acclimation (at 34 degrees C), using 57Co 15 micron microspheres. In non-acclimated dehydrated rats, CO decreased while heart rate (HR) increased significantly. Following acclimation CO increased without any change in HR; during dehydration CO remained elevated together with a significant increase in HR. In non-acclimated rats at low dehydration blood perfusion to peripheral thermoregulatory areas increased while perfusion of splanchnic area decreased; at high dehydration level peripheral blood flow decreased whereas splanchnic blood flow was augmented. In acclimated dehydrated rats, CO distribution to thermoregulatory areas did not change while perfusion of the splanchnic area decreased. It is suggested that following acclimation, the increased CO contributes to maintenance of thermoregulatory peripheral blood flow; in non-acclimated rats severe dehydration leads to augmented blood flow in the permeable splanchnic vascular bed, increasing efflux of plasma protein and failure of plasma volume conservation.
利用57钴15微米微球体，在热适应（34摄氏度）前后，对脱水（37摄氏度）且麻醉（硫喷妥钠）的大鼠的心输出量（CO）及其分布进行了研究。在未适应的脱水大鼠中，心输出量下降，而心率（HR）显著增加。适应后，心输出量增加，心率无变化；脱水期间，心输出量保持升高，同时心率显著增加。在未适应的大鼠中，轻度脱水时外周体温调节区域的血流增加，而内脏区域的灌注减少；在高度脱水时，外周血流减少，而内脏血流增加。在适应的脱水大鼠中，体温调节区域的心输出量分布没有变化，而内脏区域的灌注减少。研究表明，适应后，心输出量增加有助于维持体温调节的外周血流；在未适应的大鼠中，严重脱水会导致渗透性内脏血管床的血流增加，血浆蛋白外流量增加，血浆容量无法维持。
