Experiments were undertaken in rats to investigate the effect of intraventrical injection of neurotensin (NT) and antineurotensin serum (ANTS) on electroacupuncture (EA) analgesia. Neurotensin administration induced a enhancement of pain threshold and increased electroacupuncture analgesia Injection of antineurotensin serum reduced the pain threshold significantly and diminished the effect of electroacupuncture analgesia. Furthermore, pre-injection of naloxone 100?g intraventrically could weaken analgesic effect of NT and NT-EA analgesia. These results indicate that neurotensin in central nervous system is involved in pain modulation and plays a role in EA analgesia The effect of neurotensin may be partly conducted by endogenous opiate peptides.

In order to investigate the possibility that oxytocin (OT) is involved in stress reaction, the effect of OT or antioxytocin serum (AOTS) on rat swimming maintaining time was observed. On intraventrncularly administrating 0.625, 1.25, 2.5 and 5.0ng OT 5min before swimming,the swimming maintaining time was 29.32?5.84%, 44.92?4.54%. 60.18?4.21% and 80.48?3.62% shorter than that before injection,respectively.All the swimming maintaining time of the experimental groups was shorter significantly than that of the control group which was intraventricularly injected saline (p

The effects of electro-and chemo-stimulating (ES, CS) supraoptic nucleus (SON) on analgesia and electroacupuncture (EA) analgesia were observed using potassium inotophoresis induced tail-flick in rats. The results showed that: different electrical current (12.5 ~ 50 ?A) stimulating SON elevated the PT (P

Methods including stimulation, cauterization, of nuclei and measurement of pain threshold were used to clarify the role of paraventricular nucleus of hypothalamus (PVH) in pain regulation. Results showed that electrical or L-glutamate sodium stimulation of PVH could elevate the pain threshold in the rat dose-dependently, electrical cauterization of PVH could reduce the pain threshold; and removal of the pituitary gland could not influence the effect of L-glutamate sodium on pain threshold. These results suggest that PVH may play an important role in pain regulation.

The microinjection of brain nuclei and potassium iontophresis induced tail flick were used to investigate the effect of injecting oxytocin (OT) or anti-oxytocin serum (AOTS) into locus ceruleus (LC) on the pain threshold (PT) and morphine analgesia. The result showed that OT injection into LC could enhance PT, while ATOS injection could reduce PT. The OT injection could strengthen morphine analgesia, but AOTS injection could antagonize this action. These results suggest that the OT analgesia and OT-enhanced morphine analgesia were related with the locus ceruleus.

In this study, image quantitative analysis was made to investigate the effect of scald on arginine vasopressin (AVP) positive cells in the supraoptic nucleus (SON) stained with immunohistochemical method. Results showed that there was a decrease in the volume of AVP positive substance in the cells of SON following scald, which was significant immediately after scald (P

The contents of ir-oxytocin (it-OT), ir-Arg-yasopressin (ir-AVP) and ir-?-endorphin (ir-?-EP) in hypothalamus, pituitary and plasma were measured by. radioimmunoassay (RIA) when the rats were swimming. It was showed that the ir-OT contents in hypothalamus, pituitary and plasma were significantly increased in the animals having swum 1, 5, 15 and 20min (P