Role of phosphatidylinositol 3-kinase p110β in spinal dorsal horn neurons in the development of arthritic pain in rats: relationship with TRPV1 and ASIC1a / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of phosphatidylinositol 3-kinase (PI3K) p110β in spinal dorsal horn neurons in the development of arthritic pain (AP) in rats and the relationship with transient receptor potential vanilloid 1 (TRPV1) and acid-sensing ion channel (ASIC)1 a.Methods Forty adult female Sprague-Dawley rats in which intrathecal catheters were successfully placed,aged 3 months,weighing 250-300 g,were randomly divided into 4 groups (n =10 each)control group (group C),group AP,AP + PI3K p110β missense oligo-deoxynucleotide group (group MS) and AP + PI3K p110β antisense oligo-deoxynucleotide group (group AS).AP was induced by injecting complete Freund's adjuvant into the ankle joint cavity of right hindpaw.Normal saline 20 μl,missense oligo-deoxynucleotide 15 μg (20μl) and antisense oligo-deoxynucleotide 15 μg (20 μl) were administered intrathecally once a day for 6 consecutive days starting from the time immediately after arthritis was induced in groups AP,MS and AS,respectively.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured 1 day before operation (T0) and on days 4,7,10 after operation (T1-3).The rats were then sacrificed after the last measurement of pain threshold at T3.L4-6 segment of the spinal cord was removed for detection of expression of PI3K p110β (by Western blot),and TRPV1 and ASICla (by immunohistochemistry)in spinal dorsal horn neurons.Results Compared with group C,MWT and TWL were significantly decreased atT1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was up-regulated in the other 3 groups(P＜ 0.01).MWT and TWL were significantly higher at T1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was lower in group AS than in groups AP and MS (P ＜ 0.01).Conclusion PI3K p110β in spinal dorsal horn neurons is involved in the development of AP in rats,and the mechanism is related to up-regulation of TRPV1 and ASIC1a expression in spinal dorsal horn neurons.