2005 Fiscal Year Final Research Report Summary
Study on autonomous nerve regeneration-Experimental approach to regeneration of cavernous nerve
| Project/Area Number |
16591605
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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 |
Urology
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| Research Institution | Sapporo Medical University |
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Principal Investigator |
ITOH Naoki Sapporo Medical University, School of Medicine, Associate Professor, 医学部, 助教授 (60193504)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Atsushi Sapporo Medical University, School of Medicine, Assistant Professor, 医学部, 講師 (20274946)
TSUKAMOTO Taiji Sapporo Medical University, School of Medicine, Professor, 医学部, 教授 (50112454)
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| Project Period (FY) |
2004 – 2005
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| Keywords | nerve regeneration / cavernous nerve / nerve injury / erectile dysfunction / neurotrophic factor / aging / castration |
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| Research Abstract |
1.Development of a biodegradable conduit graft for axonal regeneration of the cavernous nerve in a rat model
The rationale for the conduit graft for axonal regeneration is supported by several hypotheses, suggesting that 1)it shields nerves from the external environment and prevents fibrosis, 2)it ensure space for axonal regeneration and 3)it provides a favorable scaffold for Schwann cells and neurotrophic factors related to axonal sprouting. In the current study collagen sponge enhanced the regeneration and maturation of the cavernous nerve, which led to further functional recovery. Collagen sponge may have additional potential to provide a favorable environment for Schwann cells. Since the main advantage of biodegradable materials is that they are absorbed in the body, cavernous nerve regeneration with copolymer conduit and collagen sponge can be applied in patients with radical prostatectomy that compromise the bilateral cavernous nerves.
2.Study on nerve regeneration-related gene exp
… More
ression in a rate model with cavernous nerve injury and in an aged-rat model
Neurturin, a nerutrophic factor, is widely distributed in the penile cavernosum and its receptor, GFRa2 is strongly positive in more than 90% of the neurons that are projected from the penis. Moreover, GFRa2-knockout mice showed very little expression of nNOS-positive nerve fibers in the corpus cavernosum. In the current study, GFRa2 and nNOS mRNA expression levels in RR-PCR were closely correlated each other and their expressions decreased by age and castration. It is well known that NGF receptors were lower aged dorsal root ganglia than in young adult rats. The reason for the reduced expression of the receptors is thought to be reduced retrograde transport of neurotrophic factors by age-induced reduction of mRNA expression of neurotrphic factors in the target organs. Cavernous tissue has been reported to show apoptosis and subsequent fibrosis with aging or castration. Thus, the current data combined with data in the literature, suggests that the status of the penile cavernosum, a target organ of the cavernous nerve, is involved in expression and regeneration of nNOS-positive neurons. In addition, plasticity of nNOS-positive neurons may require not only neurons themselves but also an intact target organ (penile cavernosum) through neurotrophic factors. Less
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