Change Of Blood Flow And Expression Of Kv1.5 MRNA In Schwann Cells Of Rabbit Sciatic Nerve After Experimental Electrical Injure

With the development of our society, electrical injure has become a very common trauma. Besides the pathology changes of nerve itself after burning, the change of microcirculation of nerve also plays an important role in the process of nerve regeneration. Many studies show that the blood flow of tissue will change when peripheral nerve is damaged by the electrical current. But there are few studies on the change of nerve blood flow. So we investigated the change of blood flow and blood vessel after sciatic nerve of rabbit injured by different electrical voltage with Laser Doppler flowmeter and observed the change of the blood vessel and collagenous fiber was observed by immunohistochemical method.The delay rectifier K+ channels have close connection with the proliferation of the Schwann cells. It can change the activity of the delay rectifier K~+ channels and consequently affect the proliferation of Schwann cells. There is still no answer to the change of proliferation of Schwann cells after electrical injury now. We studied the expression of Kv1.5 mRNA of Schwann cells in rabbit sciatic nerve after electrical injury, and compared their differences by reverse transcription polymerase chain reaction(RT-PCR) at different time points.The First Part: Change of Blood Flow and Blood Vessel in Rabbit Sciatic Nerve Injured by Electrical CurrentObjective: To study the change of blood flow and blood vessel after sciatic nerve injured with different electrical voltage. Methods: The experimental animals were randomized into 3 groups according to the injured electrical voltage: 50v, 75v, and 100v group. The change of blood flow of sciatic nerve was observed with Laser Doppler flowmeter instantly, 1 week, 1 month and 2 month. The change of the blood vessel and collagenous fiber was observed by immunohistochemical methods (SABC method). Results: The sciatic nerve blood flow increased in all groups after damaged. In the 50v group, the nerve blood flow regained in 2 month after electrical injury (p>0.05). In the 75v and 100v , the nerve blood groups flow decreased by 14.5%and 23.5% compared with the normal, and there was little collagen I aggradations in 50v injury grouping at each time. The palm collagenous fibers in epineurium and perineurium were observed in 75v and 100v injured groups. Collagen aggradations increased more significantly in 100v group at the second month. Conclusion:The restoration of sciatic nerve blood flow is prolonged with increased injured electrical voltage. The collagen aggradations after electrical injury may be one of the reasons of nerve blood flow decrease.The Second Part: Expression of Kv1.5 mRNA in Schwann Cells of Rabbit Sciatic Nerve after Electrical Injured ExperimentallyObjective: To observe the expression of Kv1.5 mRNA in Schwann cells of rabbit sciatic nerve after electrical injured experimentally, and study the influence of Schwann cells proliferation after injured by different voltage. Methods: The experimental animals were randomized into 50v group, 100v group and control group. To separate Schwann cells from the injured region with trypsin and collagenase. The expression of Kv1.5 mRNA of Schwann cells in all groups were compared by reverse transcription polymerase chain reaction (RT-PCR) at different time points. Results: Kv1.5 mRNA of Schwann cells has been expressed in all groups and more significant from 3 day to 7 day. There is no obviously difference between 50v electrical injury group and control group(P > 0.05).The expression of Kv1.5 mRNA of Schwann cell in 100v electrical injury group is low , which has a significant difference with other groups(P < 0.05). Conclusion: The expression of Kv1.5 mRNA in Schwann cells increased when nerve were injured by low voltage. And which decreased with the adding of injured voltage. The expression of Kv1.5 mRNA was decreased after electrical injured 1 week ago.