Previous clinical studies have demonstrated that gabapentin, a drug that binds to the voltage-gated calcium channel alpha2delta1 subunit proteins, is effective in the management of neuropathic pain, but there is limited evidence that addresses the participation of glial cells in the anti-allodynic effects of this drug. The present study investigated the participation of glial cells in the anti-nociceptive effects of gabapentin in rats with trigeminal neuropathic pain produced by mal-positioned dental implants. Under anesthesia, the left mandibular second molar was extracted and replaced by a miniature dental implant to induce injury to the inferior alveolar nerve. Mal-positioned dental implants significantly decreased the air-puff thresholds both ipsilateral and contralateral to the injury site. Gabapentin was administered intracisternally beginning on postoperative day (POD) 1 or on POD 7 for three days. Early or late treatment with 0.3, 3, or 30 microg of gabapentin produced significant anti-allodynic effect in the rats with mal-positioned dental implants. On POD 9, in the mal-positioned dental implants group, OX-42, a microglia marker, and GFAP, an astrocyte marker, were found to be up-regulated in the medullary dorsal horn, compared with the naive group. However, the intracisternal administration of gabapentin (30 microg) failed to reduce the number of activated microglia or astrocytes in the medullary dorsal horn. These findings suggest that gabapentin produces significant anti-nociceptive effects, which are not mediated by the inhibition of glial cell function in the medullary dorsal horn, in a rat model of trigeminal neuropathic pain.
Amines ; Anesthesia ; Animals ; Astrocytes ; Calcium Channels ; Cyclohexanecarboxylic Acids ; Dental Implants ; gamma-Aminobutyric Acid ; Horns ; Mandibular Nerve ; Microglia ; Molar ; Neuralgia ; Neuroglia ; Proteins ; Rats

Henoch-Schonlein purpura is a systemic leukoclastic vasculitis that predominantly affects small vessels. This results in purpura, abdominal pain, arthralgia and occasional sometimes nephritis. Gastrointestinal involvement occurs in 50~75% of the patients. The small bowel and colon are relatively commonly affected, but the gastric involvement is rare. Endoscopic findings include mucosal edema, hemorrhagic changes, erosions and superficial ulcers. However, deep gastric ulcers are rarely observed in Henoch-Schonlein purpura and have not been reported yet. We report a patient with typical Henoch-Schonlein purpura who presented with melena due to bleeding from multiple deep gastric ulcers and got improved with administration of high dose corticosteroid.
Abdominal Pain ; Arthralgia ; Colon ; Edema ; Hemorrhage* ; Humans ; Melena ; Nephritis ; Purpura ; Purpura, Schoenlein-Henoch* ; Stomach Ulcer* ; Ulcer ; Vasculitis