1 Dynorphin B is a novel opioid tridecapeptide.

2 Aim To investigate the changes of dynorphin and enkephalin with naloxone in rat's brain tissue and the pain threshold of tail flick after positive and negative acceleration loaded.

3 Objective To study the effect of oxytocin(OT) on pain modulation in periaqueductal gray(PAG) and its relation to endogenous dynorphin A 1-13 .

4 Objective To study the effect of oxytocin(OT)on pain modulation in spinal cord and its relation to endogenous met-enkephalin and dynorphin A_(1-13).

5 Blood vase of lung brain with hypoxia have been contracted by the plasma dynorphin which have depressed respiratory action.

6 Results Three opioid peptides decreased with the course of diabetes and dynorphin A1 -13was the most obvious of them.

7 Conclusion:Using the method of acupuncture point massage could enhance the level of maternal body dynorphin and reduce labor pains during the period of active phase on the first stage of labor.

8 Objective:To investigate the effects of progesterone on morphine rewarding effect and levels of dynorphin A (DynA) in rat brain.