Izvorni znanstveni članak
https://doi.org/10.3325/cmj.2016.57.530
The role of P2X3 receptors in bilateral masseter muscle allodynia in rats
Petra Tariba Knežević
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Robert Vukman
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Robert Antonić
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Zoran Kovač
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Ivone Uhač
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Sunčana Simonić-Kocijan
; Department of Prosthodontics, University of Rijeka School of Dental Medicine and School of Medicine, Rijeka, Croatia
Sažetak
Aim To determine the relationship between bilateral allodynia
induced by masseter inflammation and P2X3 receptor
expression changes in trigeminal ganglia (TRG) and the
influence of intramasseteric P2X3 antagonist administration
on bilateral masseter allodynia.
Methods To induce bilateral allodynia, rats received a unilateral
injection of complete Freund’s adjuvant (CFA) into
the masseter muscle. Bilateral head withdrawal threshold
(HWT) was measured 4 days later. Behavioral measurements
were followed by bilateral masseter muscle and TRG
dissection. Masseter tissue was evaluated histopathologically
and TRG tissue was analyzed for P2X3 receptor mRNA
expression by using quantitative real-time polymerase
chain reaction (PCR) analysis. To assess the P2X3 receptor
involvement in nocifensive behavior, two doses (6 and 60
μg/50 μL) of selective P2X3 antagonist A-317491 were administrated
into the inflamed masseter muscle 4 days after
the CFA injection. Bilateral HWT was measured at 15-, 30-,
60-, and 120-minute time points after A-317491 administration.
Results HWT was bilaterally reduced after the CFA injection
(P <0.001). Intramasseteric inflammation was confirmed
ipsilaterally to the CFA injection. Quantitative realtime
PCR analysis demonstrated enhanced P2X3 expression
in TRG ipsilaterally to CFA administration (P < 0.01). In comparison
with controls, the dose of 6 μg of A-317491 significantly
increased bilateral HWT at 15-, 30-, and 60-minute
time points after the A-317491 administration (P < 0.001),
whereas the dose of 60 μg of A-317491 was efficient at all
time points ipsilaterally (P = 0.004) and at 15-, 30-, and 60-
minute time points contralaterally (P < 0.001).
Conclusion Unilateral masseter inflammation can induce
bilateral allodynia in rats. The study provided evidence that
P2X3 receptors can functionally influence masseter muscle
allodynia and suggested that P2X3 receptors expressed in
TRG neurons are involved in masseter inflammatory pain
conditions.
Ključne riječi
Hrčak ID:
181392
URI
Datum izdavanja:
15.12.2016.
Posjeta: 789 *