The purinergic receptor P2X ligand-gated ion channel 3 (P2X3) is crucially involved in peripheral nociceptive processes of somatic and visceral pain. Endometriosis pain is considered as a kind of inflammatory and neuropathic pain. However, whether P2X3 is involved in endometriosis pain has not been reported up to date. Here, we aimed to determine whether P2X3 expression in endometriotic lesions...

BACKGROUND A genetic knock-in mouse model expressing the R192Q mutation of the α1-subunit of the Ca(V)2.1 channels frequently found in patients with familial hemiplegic migraine shows functional upregulation of ATP-sensitive P2X3 receptors of trigeminal sensory neurons that transduce nociceptive inputs to the brainstem. In an attempt to understand the basic mechanisms linked to the upregulation...

P2X receptors mediate the effects of ATP in micturition and nociception. During postnatal maturation, a spinobulbospinal reflex and voluntary voiding replace primitive voiding reflexes. This may involve changes in neuroactive compounds and receptors in bladder reflex pathways. We examined P2X2 and P2X3 receptors in bladder and spinal cord from postnatal (P0-P36, indicating number of days) and a...

Lysine residues near each end of the receptor ectodomain (in rat P2X2 Lys69 and Lys308) have been implicated in ATP binding to P2X receptors. We recorded membrane currents from human embryonic kidney cells expressing P2X subunits and found that lysine-to-alanine substitutions at equivalent positions in the P2X3 receptor (Lys63 and Lys299) also prevented channel function. Heteromeric P2X2/3 rece...

BACKGROUND The R192Q mutation of the CACNA1A gene, encoding for the α1 subunit of voltage-gated P/Q Ca2+ channels (Ca(v)2.1), is associated with familial hemiplegic migraine-1. We investigated whether this gain-of-function mutation changed the structure and function of trigeminal neuron P2X3 receptors that are thought to be important contributors to migraine pain. RESULTS Using in vitro trige...

Synthetic 21-bp-long short interfering RNAs (siRNA) can stimulate sequence-specific mRNA degradation in mammalian cell cultures, a process referred to as RNA interference (RNAi). In the present study, the potential of RNAi was compared to the traditional antisense approach, acting mainly via RnaseH, for targeting the recombinant rat pain-related cation-channel P2X3 expressed in CHO-K1 and a rat...

Patients suffering from sensory neuropathy due to skin denervation frequently have paradoxical manifestations of reduced nociception and neuropathic pain. However, there is a lack of satisfactory animal models to investigate these phenomena and underlying mechanisms. We developed a mouse system of neuropathy induced by resiniferatoxin (RTX), a capsaicin analog, and examined the functional signi...

BACKGROUND Diabetic neuropathy is a common neuropathy associated with paresthaesia and pain. The mechanisms underlying the painful conditions are not well understood. The aim of this study is to investigate the participation of purinergic P2X3 receptors in painful diabetic neuropathy. RESULTS Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ). We showed that mechanic...

PURPOSE To simultaneously monitor electrical discharges in various bladder regions and the external urethral sphincter (EUS) during voiding contractions, and to assess the functional role of myogenic modulation of the lower urinary tract (LUT) by ionotropic purinergic receptors containing the P2X3 subunit. METHODS Female Sprague-Dawley rats were anesthetized with urethane, and implanted with ...

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 musc...