ABSTRACT
ObjectiveTo establish a rat model of pure sensory nerve injury or pure motor nerve injury combined with skin defect to examine the effect of highly selective nerve injury on skin wound healing.MethodsA total of 90 male Sprague-Dawley rats were randomly and equally divided into three different groups including Group A (posterior rhizotomy + cutaneous excision wounding group),Group B (anterior rhizotomy + cutaneous excision wounding group) and Group C ( sham operation + cutaneous excision wounding group).The wound healing rate was detected at days 2,7,14 and 21 after injury.The CGRP mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) at days 1,3,7 and 14 after injury.The Bcl-2 protein expression was determined by immunohistochemistry at days 3,7,14 and 21 after injury.ResultsThe wound healing rate in the Groups A and C was significantly higher than that in the Group B at day 2 ( P ＜ 0.05 ),with no statistical difference between Group A and Group C (P ＞ 0.05 ).The wound healing rate in the Group C was higher than that in the Groups A and B at days 7 and 14 (P ＜0.05),with no statistical difference between Group A and Group B (P ＞0.05).The wound healing rate in the Groups B and C was higher than that in the Group A at day 21 ( P ＜ O.05 ),with no statistical difference between Group B and Group C ( P ＞ 0.05 ).The CGRP mRNA was expressed in three groups and the expression was up-regulated after wound.The CGRP mRNA expression in the Groups B and C was significantly higher than that in the Group A at days 1,3 and 7,with no statistical difference between Group B and Group C ( P ＞ 0.05 ).The CGRP mRNA expression was distributed as Group C ＞ Group B ＞ Group A at day 7 ( P ＜ 0.05 ) and Group B ＞ Group A ＞ Group C at day 14 (P ＜ 0.05 ).Immunohistochemistry indicated that there was no statistical difference in Bcl-2 protein expression at day 3 after injury in all groups; that the Bcl-2 protien expression in the Group C was significantly higher than that in the Groups A and B at day 7 ( P ＜ 0.05 ),with no statistical difference between Group A and Group B ( P ＞ 0.05 ) ; that the Bcl-2 protien expression was distributed as Group C ＞ Group B ＞ Group A at day 14 ; that the Bclo2 protien expression in the Group B was higher than that in the Groups A and C at day 21 (P ＜0.05),with no statistical difference between Group A and Group C (P ＞ 0.05).ConclusionsIn wound healing process,the sensory nerve plays a more important role than the motor nerve.Denervation of the nerves ( especially the sensory nerves) is not conducive to wound healing,and complete innervation is necessary for normal wound healing.