Relationship between intracellular pH and high energy phosphates in rat brain slices.

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15591642
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Anesthesiology/Resuscitation studies
• Research Institution: Oita University (2004); 大分医科大学 (2003)
• Principal Investigator: KITANO Takaaki Oita Univ., Univ.Hospital, Operating Unit(Anesthesiology), Associate Professor, 医学部, 助教授 (20211196)
• Co-Investigator(Kenkyū-buntansha): NISIMARU Naoko Oita Univ., Faculty of Medicine Physiology, Associate Professor, 医学部, 助教授 (60101086)
• Project Period (FY): 2003 – 2004
• Keywords: ^<31>P-NMR / CO_2 acidosis / Brain Slice / intracellular pH

Research Abstract

We examined the effect of acidosis induced by increase of CO_2 tension in artificial cerebrospinal fluid(ACSF) on energy metabolism in both of intact and acidic pre-conditioned rat brain ex vivo. The levels of high-energy phosphates and pHi in the intact and acidic preconditioned brain slices were measured using ^<31>P NMR at 25℃. When CO_2 content in bubbling gas of ACSF was increased from 5% to 40%, pH_i decreased from 7.25±0.02(mean±SD,n=14) to 6.55±0.02(n=6) in intact brain slices. The level of phosphocreatine(PCr) was maintained at pH_i between 7.4 and 6.9, but decreased rapidly at pH_i less than 6.8. Following decrease in pH_i from 7.25 to 6.55, PCr levels decreased 51±0.04%(n=23).
In acidic preconditioned brain slices, the decrease of PCr level followed by decrease in pH_i was similar as that in intact slices, but at pH_i between 6.6 and 6.4 decrease of PCr level in acidic preconditioned slices was distinctly smaller than that in intact slices(71±0.04 %,n=11). These results indicate that the pretreatment of the brain with acidosis induces a tolerance in energy metabolism of the brain to subsequent periods of acidosis.

Research Products

• [Journal Article] Lactate Utilization in Rat Brain Slices Pre-Stressed by Ischemia, Heat and Drug. (2004)
  • Author(s): Kitano, T., Nisimaru, N., Kawabe, S., Iwasaka, H., Noguchi, T.
  • Journal Title: Anesthesiology 101 Pages: A786
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Effects of intracellular acidosis on the steady state rates of creatine kinase in rat brain slices. (2003)
  • Author(s): Kitano, T., Nisimaru, N., Kawabe, S., Nakamura, T., Iwasaka, H., Noguchi, T.
  • Journal Title: Anesth Analg 96 Pages: S171
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Monocarboxylates and glucose utilization as energy substrates in rat brain slices under selective glial poisoning - a ^<31>P NMR study. (2003)
  • Author(s): Kitano, T., Nisimaru, N., Shibata, E., Iwasaka, H., Noguchi, T., Yokoi, I.
  • Journal Title: Molecular and Cellular Biochemistry 244 Pages: 77-81
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Monocarboxylates and glucose utilization as energy substrates in rat brain slices under selective glial poisoning-a ^<31>P NMR study. (2003)
  • Author(s): Kitano, T., Nisimaru, N., Shibata, E., Iwasaka, H., Noguchi, T., Yokoi, I.
  • Journal Title: Molecular and Cellular Biochemistry 244 Pages: 77-81
  • Description: 「研究成果報告書概要(欧文)」より