NIDA Res Monogr. 1986 ; 75(): 385-8.

Dynamic changes in the levels of striatal proenkephalin mRNA and large molecular weight enkephalin containing peptides following electroacupuncture.

Tsou K, Zheng M, Ding XH.

Shanghai Institute of Materia Medica, Academia Sinica, Shanghai, China.

Electroacupuncture has been shown to increase met- and leu-enkephalin contents in rat striatum and hypothalamus. Its mechanism was further studied by measuring the levels of the large molecular weight enkephalin containing peptides (LECP), processed intermediates, free leu-enkephalin as well as proenkephalin mRNA in the striatum of rats decapitated at different times after the termination of 30 min electroacupuncture. A prominent increase of leu-enkephalin was seen in rats decapitated immediately after electroacupuncture. This increase returned to control level at 0.5 h. The levels of LECP and intermediates began to elevate at 1 h after electroacupuncture, reached a plateau at 8 h and lasted for 96 h. A second phase of smaller but longer lasting increase of leu-enkephalin appeared at 8-96 h. The proenkephalin mRNA amount measured by dot-blot procedure increased 3-5 folds starting at 1 h and lasting for at least 48 h.