1998 Fiscal Year Final Research Report Summary
A study of the effect of chronic renal failure on the cochlear function
| Project/Area Number |
08671990
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | St.Marianna University School of Medicine |
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Principal Investigator |
OHASHI Toru Professor.St.Marianna University School of Medicine, 医学部, 教授 (80111376)
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| Co-Investigator(Kenkyū-buntansha) |
KINOSHITA Hirotsugu Research Associate St.Marianna University School of Medicine, 医学部, 助手 (00271370)
KENMOCHI Mutsumi Research Associate St.Marianna University School of Medicine, 医学部, 助手 (10257397)
OCHI Kentaro Lecture St.Marianna University School of Medicine, 医学部, 講師 (20214158)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Electrocochleography (ECoG) / Endocochlear Potential (EP) / chronic renal failure / 5 / 6 Nephrectomy / Noise Exposure / Puromycin Aminonucleoside / Adenine |
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| Research Abstract |
This study aimed to evaluate electrophysiologically the cochlear function of guinea pigs that underwent a five-sixths nephrectomy and additionally, to explore the synergistic action between chronic renal failure( CRF ) and noise. Cochlear potentials were recorded at 1,2,3 months postoperatively. Slight changes in compound action potential and cochlear microphonics were seen at 1 month postoperatively, while moderate and profound changes were seen at 2 and 3 months. Endocochlear potential showed no significant reduction. The results indicate that CRF may be an etiologic factor for cochlear dysfunction and that the hair cells seem likely to be a main site of the lesion. One month postoperative animals were exposed to a boadband noise. In contrast to control animals, the test animals demonstrated no recovery from the decrease in compound action potential and cochlear microphonics that occurred immediately after noise exposure. This suggests a synergistic interaction between CRF and noise.
In the following experiment, we succeded to create the three animal groups with different CRF : 1) 5/6 nephrectomized rats 2) Puromycin Aminonucreoside ( PAN ) injected rats 3) Guinea pigs bred with Adenine included feed. The EcoG study demonstrated the most marked changes in the potentials in 1) animals group and merely slight potential changes in 2) animals which presented hyper-lipemia kidney.
Histological pictures for each group's kidneys showed the different findings. However, the relation between these pathological pictures and the cochlear dysfunction remains unresolved, study of which is now in progress.
In addition, we are making a new plan to investigate the vulneravility and it's difference across above mentioned three animal group's cochleas due to noise exposure.
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