Barratt T M, Walser M
J Clin Invest. 1969 Jan;48(1):56-66. doi: 10.1172/JCI105974.
Radiosulfate, (35)SO(4), and radiobromide, (82)Br, were administered simultaneously to rats and dogs. In rats, the apparent volume of distribution of (82)Br averaged 30% of body weight and was constant between 0.5 and 35 hr after injection. The apparent volume of distribution of (35)SO(4), corrected for urinary loss, increased by 6% body weight/hr: the extrapolated volume at zero time was 88% of bromide space. Analysis of individual tissues and carcasses for (82)Br and inorganic (35)SO(4) showed that equilibration of both isotopes in several organs and in the whole carcass was rapidly achieved within 1 to 2 hr: no further increase in measured spaces occurred in 24 hr. The carcass inorganic sulfate space was 92%+/-2% of the bromide space in intact rats, and showed no increase with time. However, a progressively greater fraction of the injected (35)SO(4) was not recovered, owing to metabolic alteration. In eviscerated rats, the inorganic sulfate space was a smaller and much more constant fraction (79.8% +/-0.4%) of the bromide space, showing that at least 20% of body bromide (and hence chloride) is nonextracellular. The viscera chiefly responsible for the higher ratio of spaces in the intact animal were the liver, small bowel, and kidney. In the last two organs, excess inorganic (35)SO(4) (beyond the bromide space) was attributable to trapped transcellular fluid in which sulfate had been concentrated more than chloride (or bromide). Excess sulfate in liver and cartilage could not be explained in this manner: the results suggest passive binding of sulfate, but could reflect active cell uptake in these tissues. No excess sulfate was found in skin or tail. The implications of these observations with respect to the distribution of body chloride and the measurement of extracellular space are discussed. The extracellular volume of the rat is estimated to be 24% of body weight.
将放射性硫酸盐（³⁵SO₄）和放射性溴化物（⁸²Br）同时给予大鼠和狗。在大鼠中，⁸²Br的表观分布容积平均为体重的30%，且在注射后0.5至35小时之间保持恒定。经尿流失校正后的³⁵SO₄的表观分布容积以每小时6%体重的速度增加：零时的外推容积为溴化物空间的88%。对各个组织和 carcass进行⁸²Br和无机³⁵SO₄分析表明，两种同位素在几个器官和整个 carcass中均在1至2小时内迅速达到平衡：在24小时内测量的空间没有进一步增加。完整大鼠 carcass的无机硫酸盐空间为溴化物空间的92%±2%，且不随时间增加。然而，由于代谢改变，注入的³⁵SO₄中有越来越大的部分未被回收。在去内脏的大鼠中，无机硫酸盐空间占溴化物空间的比例较小且更为恒定（79.8%±0.4%），表明至少20%的体内溴化物（以及因此的氯化物）是非细胞外的。在完整动物中导致空间比例较高的主要内脏器官是肝脏、小肠和肾脏。在最后两个器官中，过量的无机³⁵SO₄（超过溴化物空间）归因于被困的跨细胞液，其中硫酸盐的浓度高于氯化物（或溴化物）。肝脏和软骨中的过量硫酸盐无法用这种方式解释：结果表明硫酸盐存在被动结合，但可能反映了这些组织中的主动细胞摄取。在皮肤或尾巴中未发现过量的硫酸盐。讨论了这些观察结果对体内氯化物分布和细胞外空间测量的意义。估计大鼠的细胞外容积为体重的24%。 （注：“carcass”直译为“屠体”，这里结合语境意译为“躯体”更合适，但按要求未做改动）
