title: Spinal cord brain-derived neurotrophic factor levels increase after dexamethasone treatment in male rats with chronic inflammation.
abstract: Dexamethasone is widely used in the therapy of chronic inflammatory diseases for its pain-modulating effects. The objective of this study was to evaluate the effect of dexamethasone on nociception and local inflammation, and the levels of brain-derived neurotrophic factor (BDNF) in the spinal cord in male rats with chronic inflammation induced by complete Freund's adjuvant (CFA). Rats were randomly divided into a control group (not manipulated) and 2 CFA-induced chronic inflammation groups (in the 15th post-CFA injection): 1 injected with vehicle (saline solution) and 1 received dexamethasone (0.25 mg/kg) for 8 days. The hot-plate and electronic von Frey tests were performed 24 h after the end of treatment. BDNF spinal cord levels were determined by enzyme-linked immunosorbent assay (ELISA). The level of inflammation in the tibiotarsal joint (the ankle region) was evaluated histologically at the end of treatment. Dexamethasone produced significantly increased latency in the hot-plate test (one-way ANOVA, p < 0.05) and withdrawal threshold in the electronic von Frey test (p < 0.005). The dexamethasone group showed increased spinal cord BDNF levels compared to the other groups (one-way ANOVA p, < 0.05). Histological analysis showed a local inflammatory response only in animals treated with vehicle, which demonstrated that the dexamethasone treatment decreased the inflammatory process. Our findings corroborate the antinociceptive and anti-inflammatory properties of dexamethasone. In addition, we showed that the dexamethasone treatment increased BDNF levels in the spinal cord; its pain- modulating effects can be attributed to this effect.
authors: Laboratório de Farmacologia da Dor, Departamento de Farmacologia, Instituto de Ciências Básicas da Saúde, Porto Alegre, Brazil.
authors: Gabriela
authors: G
authors: Laste
authors: Joanna
authors: J
authors: Ripoll Rozisky
authors: Isabel Cristina
authors: IC
authors: de Macedo
authors: Vinicius
authors: V
authors: Souza Dos Santos
authors: Izabel Cristina
authors: IC
authors: Custódio de Souza
authors: Wolnei
authors: W
authors: Caumo
authors: Iraci L S
authors: IL
authors: Torres
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D019208:Brain-Derived Neurotrophic Factor / Q000134:cerebrospinal fluid*; D002908:Chronic Disease; D003907:Dexamethasone / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005620:Freund's Adjuvant / Q000633:toxicity; D007249:Inflammation / Q000134:cerebrospinal fluid / Q000139:chemically induced / Q000188:drug therapy; D008297:Male; D010146:Pain / Q000134:cerebrospinal fluid*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D019208:Brain-Derived Neurotrophic Factor; D003907:Dexamethasone; D005620:Freund's Adjuvant