[Effect of the heat shock protein 27 on NOS expression of spinal cord anterior hornmotoneurons after brachial plexus avulsion].

Aim: To observe the effect of heat shock protein 27 (Hsp27) on nitric oxide synthase (NOS) of spinal cord anterior horn after brachial plexus roots avulsion.

Methods: Sixty male adult Wistar rats were divided into control and experiment groups at random. The experiment group subjected to heat shock under 45 degrees C for 15 min, and maintained under 42 degrees C for 20 min subsequently. After recovering 24 h under the room temperature, the nerves of brachial plexus were avulsion with microhemostatic forcep. In a span from 12 h to 7 d, these animals were killed at different time. But the control group only received the surgery of the nerve roots of brachial plexus avulsion. The freeze sections of spinal cord were stained by NADPH-d histochemistry, HSP27 immunohistochemical.

Results: (1) In experiment group, the motoneuron began to express NOS abundantly at 12 h after avulsion (A=0.13625). Then the NOS-positive neurons declined quickly, but in control group, the motoneuron began to express NOS at the 5th day after lesion. (2) Hsp27 begin to show the peak at 1 d in experiment and control groups, but the experiment group were more strong than the control group.

Conclusion: Hsp27 inhibited NOS of motoneuron after avulsion and brought into full play the cytoprotection.