| Project/Area Number |
04557010
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General pharmacology
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| Research Institution | Kagawa Medical School |
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Principal Investigator |
ABE Youichi Kagawa Medical School, Department of Pharmacology, Professor, 医学部, 教授 (10047227)
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| Co-Investigator(Kenkyū-buntansha) |
AKI Yasuharu Kagawa Medical School, Department of Pharmacology, Assistant, 医学部, 助手 (50231816)
TAMAKI Toshiaki Kagawa Medical School, Department of Pharmacology, Assistant Professor, 医学部, 助教授 (80179879)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥8,300,000 (Direct Cost: ¥8,300,000)
Fiscal Year 1993: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1992: ¥6,900,000 (Direct Cost: ¥6,900,000)
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| Keywords | Micro-dialysis / Fiber-type probe / Adenosine / Inosine / Hypoxanthin / Kidney / Ischemia / Recirculation |
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| Research Abstract |
The "bio-sampling" technique called microdialysis was originally developed by Ungerstedt and colleagues. The principle of this method is to extract metabolizes from the extracellular fluid(ECF) without removal of fluid from the tissue. The basic device is a thin (0.65 mm diameter) double lumen probe with a seim-permeable polycarbonate membrane at the tip. The probe is perfused with an isotonic saline. Small molecules cross the probe membrane by simple difusion along a concetration gradient between the perfusate and the ECF.The dialysate microsample content of various metabolizes is measured by sensitive analytical techniques including HPLC.Thus, microdialysis can be used for temporal studies of regional changes in the ECF content of various metabolizes. The method was originally designed for studies in brain tissue. However, the diameter of the microdialysis probe is 0.65 mm. This size is relatively large for the application to the kidney which is perfused at high blood flow rate. Moreover, since the kidney moves in synchronicity with the respiration, the fixation of probe is difficult. In addition, to observe the rapid responses to various stimuli high dialysis efficiency will be required for probe. Thus, in order to satisfy the above points, we have tried to develop a new microdialysis probe for the kidney. The diameter of the new probe is only 0.2 mm and the dialysis efficiency is 5 - 10 times greater than the commercial probe. Using this newly developed probe we have examined the intrarenal adenosine metabolism during ischemia and recirculation. Adenosine concentration(conc.) at basal condition was around 100 nM.Ischemia increased the adenosine conc.about 2 times. However, after the inhibition of adenosine deaminase with EHNA the adenosine conc.was increased more than 50 - 100 times during ischemia. On the other hand, adenosine conc.after the inhibition of adenosine kinase with iodotubercidine increased only 3 - 4 times. Thus, the adenosine released from the ce
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