The low frequency electrical impulses has a significant effect in pain control.Aportable low frequency therapeutic apparatus has been made in our laboratory This paper presents the structure,principle,specification and application of our therapeutic apparatus (including both mono-impulse and train-impulse models) as well as the results of its clinical application.

[Objective]The study focus on the analgesic effect of polysaccharopeptide(PSP)and discuss the mechanism of this analgesia. [Methods]A total of 80 rats were divided randomly into high dose of psp,medium dose of psp,low doses of psp,positive control group,negative control group.After intragastric(ig) administration of different(high,medium and low)doses of PSP for 6 days,The tail stimulation-vocalization test was used to observe the analgesic effect of PSP.The IL-2 and IL-2R expression in mediobasal hypothalamus(MBH) was studied immunohistochemically.[Results]After intragastric(ig) administration of PSP for 6 days,the pain threshold was increased significantly and a dose-effect relationship was observed.After PSP administration the IL-2 expression in MBH was increased,while the IL-2R expression in MBH was decreased.[Conclusion]PSP has a definite analgesic effect and its analgesic site is in the MBH.The analgesia might be produced by the binding with the IL-2R in MBH by IL-2 secreted by T cells after PSP was injected into the brain.

Aim To investigate the role of locus coeruleus(LC)-norepinephrinergic system and sympathetic nervous system in immunosuppression under cold stress, using 6-hydroxydopamine(6-OHDA) as chemical sympathectomy.Methods Rats were maintained in cold chamber at 4℃ for 4 h.The 51Cr release assay from YAC-1 cells was used to determine the splenic NK cell activity, the double staining of ABC method was employed to observe the immunoreactive expression of Fos, arginine-vasopressin(AVP), oxytocin(OT) and tyrosine hydroxylase(TH), and conventional radioimmunoassay was used to measure plasma corticosterone (CORT) concentrations.Results Central sympathectomy with intracerebroventricular(i.c.v.) injection of 6-OHDA r educed significantly the elevation of plasma corticosterone level, the expressio n of Fos in hypothalamic paraventricular nucleus(PVN) and in locus coeruleus(LC ), as well as the suppression of NK activity induced by cold stress at 4℃ for 4 h. Peripheral sympathectomy with intraperitoneal (i.p.) injection of 6-OHDA al so reversed the cold stress-induced suppression of NK cytotoxicity, but without significant effect on Fos expression in brain. Double staining showed that amon g the Fos-positive neurons in PVN only a few co-expressed Fos and AVP or Fos a nd OT, while in LC the majority of Fos-positive neurons co-expressed Fos and T H.Conclusion The mechanism of suppression of NK activity induce d by cold stress may be mediated through HPA axis activated partially by central LC-norepinephrinergic system and through the peripheral sympathetic nervous system.