Horowitz M, Samueloff S
J Appl Physiol Respir Environ Exerc Physiol. 1979 Oct;47(4):738-44. doi: 10.1152/jappl.1979.47.4.738.
Changes in body water compartments during acute dehydration before and after acclimation to heat and the role of plasma proteins in body fluid dynamics were studied in the rat. Compartment volumes, plasma and interstitial protein concentrations, and colloid osmotic pressures (COP) were measured in anesthetized (with thiopental sodium) and, if necessary, nephrectomized rats. Albumin outfluxes, total protein mass (TPM), and total albumin mass (TAM) were calculated. Nonacclimated rats conserved plasma volume (PV) as long as dehydration did not exceed 15-16% body weight loss (18.6% total body water loss). This was associated with decreased albumin outflux, elevated plasma COP, and reduced subcutaneous COP. When water loss reached 25,5%, PV and extracellular fluid volume decreased by 45 and 34%, respectively. Albumin outflux recovered, TPM and TAM decreased, and plasma COP remained high. In acclimated dehydrated rats PV remained unchanged, albumin outflux decreased, TPM and COP increased, and interstitial COP decreased. Most of the water loss was intracellular in origin. It was concluded that PV changes during dehydration are related to changes in plasma protein distribution. PV conservation rate is different in rats as compared to desert PV conservers.
研究了大鼠在适应热环境前后急性脱水过程中机体水腔室的变化以及血浆蛋白在体液动力学中的作用。在麻醉（用硫喷妥钠）且必要时进行肾切除的大鼠中测量腔室容积、血浆和间质蛋白浓度以及胶体渗透压（COP）。计算白蛋白外流、总蛋白质量（TPM）和总白蛋白质量（TAM）。未适应的大鼠只要脱水不超过体重减轻的15 - 16%（全身失水量的18.6%）就会保持血浆容量（PV）。这与白蛋白外流减少、血浆COP升高和皮下COP降低有关。当失水量达到25.5%时，PV和细胞外液量分别减少45%和34%。白蛋白外流恢复，TPM和TAM降低，血浆COP仍保持较高水平。在适应热环境的脱水大鼠中，PV保持不变，白蛋白外流减少，TPM和COP升高，间质COP降低。大部分失水量源于细胞内。得出的结论是，脱水过程中PV的变化与血浆蛋白分布的变化有关。与沙漠中的PV保持者相比，大鼠的PV保存率有所不同。
