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

Figure 2

Progesterone attenuated TMJ inflammation-induced hyperalgesia and Nav1.7 expression. (a) Serum level of P4. Serum levels of P4 in the ovariectomized groups administered 0 μg, 350 μg, or 700 μg P4 increased dose dependently. (b) Head withdrawal threshold. After induction of TMJ inflammation, the head withdrawal threshold was significantly decreased in sham rats and also dose-dependently increased in the ovariectomized groups. (c) Real-time PCR analysis for Nav1.7 expression in TG. The Nav1.7 mRNA in TG was increased by TMJ inflammation and attenuated dose-dependently by P4 in ovariectomized rats. (d) Representative immunoblotting for Nav1.7 expression in TG. Nav1.7 protein expression corresponded to mRNA expression pattern. β-Actin served as an internal control for equal loading. versus the control group; versus the sham group; versus the 0 μg group; P versus the 350 μg group. Data are expressed as mean ± SD.

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