Progesterone Attenuates Allodynia of Inflamed Temporomandibular Joint through Modulating Voltage-Gated Sodium Channel 1.7 in Trigeminal Ganglion

Figure 4

Blocking progesterone receptors partially reversed the effect of P4 on TMJ hyperalgesia and Nav1.7 expression. (a) Representative immunofluorescence of Nav1.7 and PRα/β in TG. There was colocalization between Nav1.7 and PRα/β (yellow, indicated by arrow) in TG neurons, bars = 20 μm. (b) Head withdrawal threshold. RU486 partially inhibited the repressive effect of P4 on head withdrawal threshold. (c) Real-time PCR analysis for Nav1.7 expression in TG. After induction of TMJ inflammation, Nav1.7 mRNA expression was significantly increased in the sham rats, and 700 μg P4 partially repressed TMJ inflammation-induced Nav1.7 mRNA expression. RU486 partially inhibited the repressive effect of P4 on Nav1.7 mRNA expression. (d) Representative immunoblotting for Nav1.7 expression in TG. Nav1.7 protein expression corresponded to the mRNA expression pattern. β-Actin served as an internal control for equal loading. versus the control group; versus the sham group; versus 700 μg P4 without the RU486 group. Data are expressed as mean ± SD.

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