酵素法による毛細管血中乳酸測定

標準的な酸素法による乳酸測定法(Hohorst)を改変し,微量血中の乳酸測定を行なった。採血をヘパリンコートした毛細管ピペットで行ない,血液を4容の0.6M過塩素酸(PCA)で除蛋白,PCA抽出液の中和を省略,乳酸脱水素酵素存在時と非存在時での25℃,60分反応後の340nmの吸光度を測定することにより,容易に,通常の分光光度計で(特殊な測定機器を用いず)微量血中の乳酸が測定可能であった。Standard enzymatic method for lactate determination was modified : (1) the blood was deproteinized with 4 volume of 0.6 M perchloric acid (PCA), (2) neutralization of the PCA extract was omitted, and (3) the absorbance at 340 nm was measured only once after 60 min. incubation with and without lactate dehydrogenase. Lactate level could be calculated from the absorbance difference between with and without the enzyme. One reference (any sample incubated without the enzyme) was necessary for one series of measurement. Lactate level up to 15 mmoles/1 could be determined without varying the sample volume. Use of heparin-coated capillary pipet allowed easy and accurate sampling of 45μ1 of blood from the ear lobe. Lactate level in this volume of the sample could be deternined with a standard spectropho. tometer