[Effects of nitric oxide on spontaneous pain reaction and neuronal apoptosis in the spinal cord of rats induced by formalin inflammatory pain].

Objective: To observe whether formalin inflammatory pain can induce neuron apoptosis in rats spinal cord or not and the effects of nitric oxide on the spontaneous pain reaction and neuron apoptosis in the spinal cord of rats with formalin inflammatory pain.

Methods: Formalin-induced paw licking time was used to reflect the degree of spontaneous pain of rats, and the flow cytometry was used to detecte neuron apoptosis rate of spinal cord.

Results: Compared with control group, the apoptosis ratio of spinal neuron was increased in the rats with formalin inflammatory pain, and peaked at 3d after formalin injection.

[Intrathecal injection of MK-801 inhibited the NOS activity and NO content of hippocampus in rat during the process of formalin-induced inflammatory pain].

Aim: To study the effect of intrathecal injection of MK-801, a NMDA receptor antagonist, on the NOS activity and NO content of hippocampus in rat during the process of formalin-induced inflammatory pain as well as the pain behavior of rat.

Methods: The degree of pain was determined by observing the time of licking and biting the injected paw. NOS expression in the hippocampus was determined by using NADPH-d histochemical staining.

[Formalin inflammatory pain induced hippocampal neuronal apoptosis of rats].

Aim: To investigate whether formalin inflammatory pain can induce hippocampal neuronal apoptosis of rats or not.

Methods: Rats were subcutaneously injected with 0.2 ml 0.