This study was designed to investigate any correlation between the mechanism of pain development and changes of histochemically reactive zinc contents in the rat spinal ganglion following complete Freund's Adjuvant (CFA) injection, as an inflammatory pain model. Male Sprague-Dawley rats (270~290 g) were used for this study. Surgeries were done under anesthesia using pentobarbital (30 mg/kg). we injected 200 microliter of CFA subcutaneously in the dorsal aspect of one hind paw using a 30- gauge needle and an 1 mL syringe. Semmes-Weinstein monofilaments was used to test for mechanical hyperalgesia. Finally, zinc selenite autometallography (AMG) was done by Danscher's method. The rat suffered from severe painful swelling of the hindpaw 1 day after a CFA inoculation. Changes in pain threshold were significantly changed on 1 day, and lasted during experiment period of 3 weeks after the CFA inoculation. In control group, ganglion cells vary in size from 15 to 100 micrometer. The smaller neurons are strongly stained with AMG, whereas the larger cells are not almostly stained. Each large ganglion cell is surrounded by perineuronal satellite cells, showing apparent AMG stainity. In experiment group, AMG-positive small ganglion cells increased on 1 day after CFA inoculation, and showed a peak in cell number at 3days group, and decreased gradually after 7 days. We found a small number of large-sized ganglion cells with AMG stainity 7 days and 3 weeks after CFA inoculation. Our results indicate that zinc may be involved in pain mechanism in the spinal ganglion level.
Anesthesia ; Animals ; Cell Count ; Freund's Adjuvant ; Ganglia, Spinal* ; Ganglion Cysts ; Humans ; Hyperalgesia ; Male ; Needles ; Neurons ; Pain Threshold ; Pentobarbital ; Rats* ; Rats, Sprague-Dawley ; Satellite Cells, Perineuronal ; Selenious Acid ; Syringes ; Zinc*

OBJECTIVETo evaluate the effect of tetrandrine (Tet) on nitroglycerin(GTN)-induced activation of the satellite cells released inflammatory cytokines and to explore its mechanism.

METHODNeonatal rat satellite cells of trigeminal ganglia were cultured and separated into three groups. Group CON: the cells were normal cultured; Group TGN: the cells were cultured with 0.55 mmol x L(-1) GTN; Group Tet: the cells were treated with 0.55 mmol x L(-1) GTN and 1 x 10(-7) mol x L(-1) Tet respectively. Cell viability after GTN and Tet was detected by AlamarBlue assay. The concentration change of intracellular Ca2+ ([Ca2+]i) in single satellite cell loaded with Fluo-3/AM was determined by laser scanning confocal microscopy. NF-kappaB and IL-1beta mRNA levels were determined by FQ-PCR. Through double-immunofluorescent staining identifies satellite cells and determines the expression of NF-kappaB protein.

RESULTSatellite cells activities decreased with GTN stimulating, but according to the viability and modality of the cells, 1 x 10(-7) mol x L(-1) Tet was the suitable prophylaxis. Tet can inhibit the elevation of cytosolic free calcium of rat satellite cell and decrease the mRNA and protein levels of NF-kappaB and the mRNA levels of IL-1beta.

CONCLUSIONVia preventing Ca2+ influxion, Tet inhibited NF-kappaB activation of satellite cell which decreased IL-1beta expression.

Animals ; Benzylisoquinolines ; pharmacology ; Calcium ; metabolism ; Calcium Channel Blockers ; pharmacology ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation ; drug effects ; Interleukin-1beta ; genetics ; NF-kappa B ; genetics ; metabolism ; Nitroglycerin ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Satellite Cells, Perineuronal ; drug effects ; metabolism ; Trigeminal Ganglion ; drug effects ; metabolism