| Autor: |
Costa YM; Universidade Estadual de Campinas - Unicamp, Piracicaba Dental School, Department of Biosciences, Piracicaba, SP, Brazil., Herculiani CCF; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Soares FFC; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Azevedo MCS; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Conti PCR; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Prosthodontics, Bauru, SP, Brazil., Dionísio TJ; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Oliveira GM; Universidade de São Paulo - USP, Hospital for Rehabilitation of Craniofacial Anomalies, Bauru, SP, Brazil., Faria FAC; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Santos CF; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Garlet GP; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil., Bonjardim LR; Universidade de São Paulo - USP, Bauru School of Dentistry, Department of Biological Sciences, Bauru, São Paulo, SP, Brazil. |
| Abstrakt: |
This study aimed to assess the influence of streptozotocin (STZ)-induced diabetes on the nociceptive behavior evoked by the injection of hypertonic saline (HS) into the masseter muscle of rats. Forty male rats were equally divided into four groups: a) isotonic saline control, which received 0.9% isotonic saline (IS), (Ctrl-IS); b) hypertonic saline control, which received 5% HS (Ctrl-HS); c) STZ-induced diabetic, which received IS, (STZ-IS); d) STZ-induced diabetic, which received HS (STZ-HS). Experimental diabetes was induced by a single intraperitoneal injection of STZ at dose of 60 mg/kg dissolved in 0.1 M citrate buffer, and 100 μL of HS or IS were injected into the left masseter to measure the nociceptive behavior. Later on, muscle RNA was extracted to measure the relative expression of the following cytokines: cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and interleukins (IL)-1β, -2, -6, and -10. One-way analysis of variance (ANOVA) was applied to the data (p < 0.050). We observed a main effect of group on the nociceptive response (ANOVA: F = 11.60, p < 0.001), where the Ctrl-HS group presented the highest response (p < 0.001). However, nociceptive response was similar among the Ctrl-IS, STZ-IS, and STZ-HS group (p > 0.050). In addition, the highest relative gene expression of TNF-α and IL-6 was found in the masseter of control rats following experimental muscle pain (p < 0.050). In conclusion, the loss of somatosensory function can be observed in deep orofacial tissues of STZ-induced diabetic rats. |
