ABSTRACT
Objective To investigate the effects of inhibiting vesicular glutamate transporters (VGLUT) on pain behaviors in animals. Methods The latency in hot plate test, number of writhes in acetic acid and licking time in formeldehyde solution (formalin) tests were recorded to determine the analgesic effect of Chicago sky blue 6B (CSB6B), a selective VGLUT inhibitor. Results Intraperitoneal administration of CSB6B did not affect the acute thermal pain responses in hot plate test. In acetic acid writhing, compared with control group (26.50 ±2.97), CSB6B (2.5 mg/kg, ip) significantly attenuated the acetic acid-induced writhing (8.22±1.90) 30 min after administration (P<0.01);CSB6B (2.5 mg/kg, ip) significantly reduced the acetic acid-induced writhing(9.60±1.84) 60 min after administration(P<0.01). In Formalin test, compared with control group(139.40±21.02), CSB6B (0.5 mg/kg, ip) significantly reduced the licking time(75.10±19.45) 30 min after administration(P<0.05) during the second phase, but not during the first phases. CSB6B(ip) did not affect the licking time 2 h after administration during the first and second phases. Conclusion Inhibition of VGLUTs activity is sufficient to attenuate the inflammatory pain and this finding suggests that VGLUT participate in regulation of inflammatory pain and be a novel therapeutic strategy for treatment of pain.