脊髓背角神经元磷脂酰肌醇-3激酶p110β在大鼠关节炎性痛形成中的作用：与辣椒素受体及酸敏感离子通道1a的关系

Role of phosphatidylinositoi 3-kinase p110β in spinal dorsal horn neurons in the development of arthritic pain in rats： relationship with TRPV1 and ASIC1a

目的评价脊髓背角神经元磷脂酰肌醇-3激酶（P13K）p110β在大鼠关节炎性痛形成中的作用及与辣椒素受体（TRPV1）及酸敏感离子通道1a（ASIC1a）的关系。方法鞘内置管成功的成年雌性SD大鼠40只，3月龄，体重250～300g，采用随机数字表法，将其分为4组（n=10）：对照组（C组）、关节炎性痛组（AP组）、AP＋PI3Kp110β错义寡核苷酸组（MS组）和AP＋P13Kp110β反义寡核苷酸组（AS组）。采用右踝关节腔内注射完全弗氏佐剂建立关节炎性痛模型，模型制备后即刻AP组、MS组、AS组分别经鞘内注射生理盐水、错义寡核苷酸15μg和反义寡核苷酸15μg，容量20μ1，1次，d，连续6d。于术前1d、术后4、7、10d时测定机械缩足反应阈（MWT）和热缩足反应潜伏期（TWL），术后10d处死大鼠，取腰段脊髓，采用Westernblot法检测脊髓背角神经元P13Kp110β表达，采用免疫组化法检测脊髓背角神经元TRPV1和ASIC1a的表达。结果与c组比较，AP组、MS组和As组术后各时点MWT降低，TWL缩短，脊髓背角神经元P13Kp110β、TRPV1和ASIC1a表达上调（P〈0．01）；与AP组和MS组比较，As组术后各时点MWT升高，TWL延长，脊髓背角神经元P13Kp110β、TRPV1和ASIC1a表达下调（P〈0．01）。结论脊髓背角神经元P13Kp110β参与大鼠关节炎性痛的形成，其机制与上调脊髓背角神经元TRPV1和ASIC1a的表达有关。

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）1a. Methods Forty adult female Sprague-Dawley rats in which intrathecal eatheters were successfully placed, aged 3 months, weighing 250-300 g, were randomly divid- ed into 4 groups （n = 10 each） ： control group （group C）, group AP, AP ＋ PI3K p110β missense oligo-deoxynu- cleotide group （group MS） and AP ＋ PI3K p110β antisense oligo-deoxynueleotide group （group AS）. AP was in- duced by injecting complete Freund＇ s adjuvant into the ankle joint cavity of right hindpaw. Normal saline 20μl, missense oligo-deoxynueleotide 15μg （20μl） and antisense oligo-deoxynucleotide 15 μg （20 μl） Were administered intratheeally once a day for 6 consecutive days starting from the time immediately after arthritis was indueed 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 ratswere 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 TRPVI and ASIC1a （by imnmnohistochemistry） in spinal dorsal horn neurons. Results Compared with group C, MWT and TWL were significantly decreased at T1-3 , and the expression of PI3K p110β, TRPV1 and ASICla was up-regulated＇in the other 3 groups （ P 〈 0.01 ）. MWT and TWL were significantly higher at T1-3, and the expression of PI3 K p110β, TRPV 1 and ASIC 1 a was lower in group AS than in groups AP and MS （ P 〈 0.01 ）. Conclusion PI3K p110β in spinal dorsal horn neurons is in- volved in the development of AP in rats, and the mechanism is related to up-regulation of TRPV1 and ASIC1a ex- pression in spinal dorsal horn neurons.