2001 Fiscal Year Final Research Report Summary
THE EFFECT OF VASOACTIVE DRUGS UPON THE SPINAL PAIN MODULATION
| Project/Area Number |
10470315
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HANAOKA Kazuo Faculty of Medicine, The University of Tokyo, Professor, 医学部・附属病院, 教授 (80010403)
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| Co-Investigator(Kenkyū-buntansha) |
IDE Yasuo Faculty of Medicine, The University of Tokyo, Lecturer, 医学部・附属病院, 講師 (60193463)
SUMIDA Toshinobu Faculty of Medicine, The University of Tokyo, Lecturer, 医学部・附属病院, 講師 (80187806)
TAGAMI Megumi Univ. of Toho, Anesthesiology, Professor, 医学部, 教授 (90107657)
KITAMURA Takayuki Faculty of Medicine, The University of Tokyo, Assistant, 医学部・附属病院, 助手 (50302609)
SEKIYAMA Hiroshi Faculty of Medicine, The University of Tokyo, Assist. Prof., 医学部・附属病院, 助手 (40301105)
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| Project Period (FY) |
1998 – 2001
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| Keywords | spinal cord / single-unitactivity / dorsal horn / wide dynamic range (WDR) cell / vasoactive drugs / pinching stimulation / calcium channel blocker / extracellar microelectroed measurement |
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| Research Abstract |
The purpose of this study is to investigate the effects of vasoactive drugs on the wide dynamic range (WDR) neuron of the dorsal horn of the feline lumber spinal cord.
Methods : Under nitrous oxide-oxygen-isoflurane anesthesia, cats of both sex were prepared with midcollicular decerebration and lumber laminectomy. The spinal cord win transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 1500-2000 micrometer from the cord dorsum. Spontaneous activity and noxiously evoked activity by pinching the receptive field on the hind paw were measured.
Diltiazem, as calcium channel blocker, 10 mg /ml (D 10 mg Group) or 20 mg/ml (D 20 mg Group) was administered on the surface of the cord dorsum by the drip method. Then, changes of the cell's firings of spontaneous and evoked activities in WDR were investigated every five minutes. Recoveries of firings were followed until the firings recovered by the control level.
Clonidine, as α 2-adrenergic agonist, 5 micro g/ml (C 5 micro g Group) or 50 micro g /ml (C 50 micro g Group) was administered as some manner of diltiazem experiment.
Results : All groups showed the suppressive effect. Diltiazem showed the suppressive effect on dose dependent manner. However, clonidine did not show the dose dependent manner.
Discussion : Our results suggested that calcium channel blocker and α2 adrenergic agonist have suppressive effects on single-unit activities of WDR neuron. Therefore, both drugs are considered to be applied on the clinical use for the chronic intractable pain patients.
Conclusion : Calcium channel and α2-adrenergic receptor are related with pain.
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