| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2000: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
|---|
| Research Abstract |
We studied the effect of a slight nerve stretching stresses on the peripheral nerve in rats, which induces no irreversible nerve dysfunction. One-hour continuous stretching was performed on the upper limb at traction forces of 1N, 2N, 5N and zero-N (control group). Amplitude did not change significant during traction in the 1N traction group. In the 5N group, the amplitude did not recover to the pretraction level even 30 minutes after release of the traction. In the 2N group, amplitude decreased 60 of the control level but recovered rapidly after release of the traction load. Based on the results described above, 2N was defined as the traction force in this study, since 2N did not induce any function deficit of peripheral nerve. Stretching for 1 hour was applied to the rat forelimb at 2 Newton (N), and the grasping strength, blood-nerve-barrier (BNB) function, light microscope and transmission electron microscope (TEM) were assessed. The grasping strength was normal and neither functional breakdown BNB nor morphological changes under light microscope were observed. However, in electron microscope study, the number of mirotubules of brachial plexus and median nerve were reduced in the internodal portion of axons, by 43% and 12% from control values, respectively. These changes were found significantly more frequently in the brachial plexus than in the median nerve.
It is now widely accepted that microtubules has a close relation to fast axonal tranport of membrane organelles. Loss of axonal microtubules by stretching injury has been hypotherically attributed to a fo* disruption of axonal transport. Even slight nerve stretching reduced the number of microtubules and * finding is more apparent in the brachial plexus than in the median nerve. These results may indicate the numbness, and other complaints around shoulder joint and upper limbs.
|
