Nitric oxide involvement in the trigeminal hyperalgesia in diabetic rats.
Trigeminal hyperalgesia frequently appears in diabetic neuralgia altering the transmission of orofacial sensory information. This study was designed to explore the effects of trigeminal hyperalgesia in streptozotocin-induced diabetes monitoring the expression of nitric oxide synthase in the trigeminal ganglion cells. The threshold to heat noxious stimuli decreased in diabetic animals. The number of NADPH-diaphorase (NADPH-d)-positive neurons significantly decreased in the diabetic rats compared with controls. Insulin treatment prevented the decreased nociceptive threshold and reduction of the number of NADPH-d-positive neurons. These findings point out that there is a relationship between the trigeminal nociceptive perception and NADPH-d neuronal expression suggesting that NO may play a role in the pathogenesis of trigeminal sensory neuropathy.
Rodella
L
L
Department of Biomedical Sciences and Biotechnology, Division of Human Anatomy, University of Brescia, Via Valsabbina 19, 25124, Brescia, Italy.
Rezzani
R
R
Corsetti
G
G
Bianchi
R
R
D000818:Animals; D002452:Cell Count; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D006930:Hyperalgesia / Q000503:physiopathology*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009249:NADP / Q000378:metabolism; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D012668:Trigeminal Ganglion / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D014276:Trigeminal Nerve / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D020433:Trigeminal Nerve Diseases / Q000503:physiopathology*
D007004:Hypoglycemic Agents; D007328:Insulin; D009569:Nitric Oxide; D009249:NADP; D019001:Nitric Oxide Synthase