[Prostaglandin inhibitor indomethacin inhibits afferent activities of Adelta and C units in the saphenous nerve of diabetic hyperalgesic rats].
The effects of a non-selective inhibitor of cyclo-oxygenase (COX) indomethacin, and exogenous prostaglandin E(2) (PGE(2)) on A(delta) units and C units in the saphenous nerve of diabetic hyperalgesic rats were studied. The results showed that the conduction velocity of A(delta) units and C units and their mechanical threshold in diabetic hyperalgesic rats were obviously decreased, and a small number of A(delta) units (4/24) and C units (2/18) produced increased spontaneous activities. Intraperitoneal injection of indomethacin in diabetic hyperalgesic rats significantly relieved mechanical hyperalgesia, and resulted in a decrease in spontaneous afferent activities of the A(delta) units and C units. Subcutaneous injection of exogenous PGE(2) into the diabetic hyperalgesic and control rats produced a significant decrease in mechanical threshold of the A(delta) units and C units, and elicited discharge from 3 A(delta) units (3/24) and 1 C unit (1/18) in diabetic hyperalgesic rats and from 2 A(delta) units (2/13) in control rats. The present data suggest that the synthesis and release of PGs are increased in diabetic neuropathy, PGs can sensitize and /or activate A(delta) units and C units and elicit hyperalgesia and allodynia in diabetic rats.
Liu
Jian
J
Department of Physiology, School of Medicine, Xi'an Jiao Tong University, Xi'an, China. physi-x@mail.xjtu.edu.cn
Zhang
Qiao-Jun
QJ
Guo
Bei-Chuan
BC
Cao
Dong-Yuan
DY
Wang
Ke-Mo
KM
D000344:Afferent Pathways / Q000187:drug effects* / Q000503:physiopathology; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005267:Femoral Nerve / Q000187:drug effects / Q000503:physiopathology; D006930:Hyperalgesia / Q000503:physiopathology*; D007213:Indomethacin / Q000494:pharmacology*; D008297:Male; D017288:Pain Threshold / Q000187:drug effects; D011448:Prostaglandin Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D011448:Prostaglandin Antagonists; D007213:Indomethacin