| Co-Investigator(Kenkyū-buntansha) |
MIYAHARA Tatsuro Pharmaceutical Science, Assoc. Prof., 薬学部(臨床分析学), 助教授 (10019119)
KOIZUNI Tamotsu Pharmaceutical Science, Prof., 薬学部(薬剤学), 教授 (90039636)
ITO Yusuke Medical Science, Dept. Anesthesiology, Prof., 医学部(麻酔科学), 教授 (70018307)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
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| Research Abstract |
Lactated Ringer's solution as well as acetated Ringer's solution are commonly used as intraoperative infusions. However, organic anions such as racemic lactate L-lactate and acetate contained in these solutions have not well understood, and superstitious thoughts about these compounds are prevailing We clarified following truths by means of rat's experiments using radioisotope and clinical laboratory data during operations of tympanoplasty under general anesthesia.
1. The blood concentration of D-lactate is deemed to be trace and not known precisely. We have cleared it 0.2 mg/dl, which is approximately 2% of that of L-lactate in normal man.
2. It has been thought that the metabolic rate of D-lactate is slow and its rate is one fourth of L-lactate, and 30% of D-lactate administered are excreted to urine without being metabolized. We have clarified that the metabolism of D-lactate of the clinical dosage is well fitted to "the first oder response" in pharmacokinetics, and only 2% of it are
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excreted to urine.
3. Although D-lactate is thought to be metabolized to L-lactate by lactate racemasa, it has been clarified that D-lactate is metabolized to pyruvate directly by non-specific enzyme of D-2-hydroxy acid dehydrogenase in mammals.
4. Acetate has been believed to be metabolized more rapidly than lactate. The metabolic rate measured by alkalizing potencies, however, has shown same with racemic lactate, L-lactate and acetate if ordinary amounts contained in Ringer's solutions are used. If three times amounts of organic anions in each Ringer's solutions, acetate has revealed more prominent alkalizing effect than racemic lactate. There are, however, no significant differences between acetate and L-lactate, and between racemic lactate and L-lactate.
5. Although serum concentration of acetate in normal man has not known yet, we have cleared that its concentration is 0.24<plus-minus>0.12 mg/dl (mean <plus-minus> SD, n=23) with wide vari
6. Deproteinezed blood samples for measuring acetate concentrations must be kept freezing with -70^ﾟC. If kept with more than above the temperature, higher values of acetate concentrations are obtained, probably due to the liberation of acetate from glucosamine of red cell membrane. Less
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