The Effect of Thyrotropin Releasing Hormone on the Somatosensory Evoked Potentials and the Ultrastructure of Myelinated Nerve Fibers in Injuried Spinal Cord.
- Author:
Seung Min LEE
1
;
Ki Chan LEE
Author Information
1. Department of Neurosurgery, College of Medicine, Korea University, Seoul, Korea.
- Publication Type:Original Article
- Keywords:
Injured spinal cord;
Thyrotropin releasing hormone;
Somatosensory evoked potential;
Myelinated nerve fiber;
Electronmicroscope
- MeSH:
Animals;
Axons;
Cats;
Evoked Potentials, Somatosensory*;
Mitochondria;
Myelin Sheath*;
Nerve Fibers, Myelinated*;
Neurofibrils;
Spinal Cord Injuries;
Spinal Cord*;
Spine;
Thyrotropin*;
Thyrotropin-Releasing Hormone*
- From:Journal of Korean Neurosurgical Society
1990;19(7):1033-1043
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of this study was to determine the effect of treatment with thyrotropin releasing hormone(TRH) on the somatosensory evoked potentials(SSEPs) and ultrastructures of myelinated nerve fibers in injured spinal cords. Spinal cords of cats were injured expermentally at the second lumbar vertebra level with 20gm-20cm(400gm-cm) impact force using modified Allen's weight drop method. The animals were treated with TRH(2mg/Kg, bolus, then 2mg/Kg/hour, IV, for 4 hours) 1 hour after injury. SSEPs were checked serially in both treated and untreated groups for 24 hours. And the fine strucures of myelinated nerve fibers in the white matters were observed in electronmicroscope before and after the injury in both groups. In treated groups, the inital positive waves were re-elicited 3 hours after injury which was eliminated immediately after injury. Fine structure of the myelinated nerve fibers were changed progressively. With time after injury, the myelinated nerve fibers showed enlarged periaxonal spaces, irregulary contoured axons, and disarray of myelin sheaths. By 4 hours after injury, there appeared marked separation and disrray of myelin sheaths, and mitochondria and neurofibrils in axoplasm showed serve degeneration. The result of this study suggested that TRH has a beneficial effect on the re-elicitation of SSEP's and the preservation of myelinated nerve fibers in the acute stage of spinal cord injury.
