title: Local intramuscular injection of a plasmid encoding human proenkepahlin attenuates incision pain in rats.
abstract: We investigated the antinociceptive effect of local intramuscular injection of a plasmid encoding human proenkephalin (pVAX1-hPPE) on postoperative pain in rats. Male Sprague-Dawley rats with incision-induced pain were intramuscularly injected into injured plantaris muscle with empty vector (pVAX1) or pVAX1-hPPE, respectively. Paw mechanical threshold and thermal latency in the 200μg pVAX1-hPPE treated rats were significantly higher at 6h and on 1day, and lasted until day 7 after intramuscular administration, respectively. The analgesic effects were reversed by methylnaltrexone, suggesting that the antinociceptive effect of pVAX1-hPPE was mediated through peripheral opioid receptor pathway. In contrast, incisional or pVAX1-treated rats did not significantly affect pain thresholds. These results demonstrated that single intramuscular injection of pVAX1-hPPE attenuated incision-induced pain in rats, and it is worthy of further study as a potential gene therapy for postoperative pain.
authors: College of Life Science and Bio-engineering, Beijing University of Technology, Beijing 100124, People's Republic of China; Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China.
authors: Chunsheng
authors: C
authors: Hu
authors: Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China.
authors: Zhenzhen
authors: Z
authors: Cai
authors: Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China.
authors: Yuxin
authors: Y
authors: Lu
authors: Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China.
authors: Xiaochen
authors: X
authors: Cheng
authors: College of Life Science and Bio-engineering, Beijing University of Technology, Beijing 100124, People's Republic of China; Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China.
authors: Zuze
authors: Z
authors: Wu
authors: Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850, People's Republic of China. Electronic address: qinglz@yahoo.com.
authors: Qinglin
authors: Q
authors: Zhang
mesh_terms: D000818:Animals; D004745:Enkephalins / Q000627:therapeutic use*; D015316:Genetic Therapy; D007273:Injections, Intramuscular; D008297:Male; D010146:Pain / Q000188:drug therapy*; D059408:Pain Management / Q000379:methods*; D017288:Pain Threshold / Q000187:drug effects; D010957:Plasmids; D011498:Protein Precursors / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004745:Enkephalins; D011498:Protein Precursors; C029992:proenkephalin
keywords: Gene therapy; Incision; Plasmid; Postoperative pain; Proenkephalin