实验性高血糖大鼠血糖水平与基础痛阈的关系

Relationship between blood glucose level and changes of pain threshold in experimental rats with hypergfycemia

目的:研究链脲霉素所致实验性高血糖大鼠血糖变化与热痛阈和机械痛阈的关系。 方法:将20只SD雄性大鼠随机分为两组,链脲霉素组(streptozotocin, STZ,n=10)和生理盐水组(n=10)两组,STZ组腹腔注射链脲霉素(50μg/kg),生理盐水组腹腔注射生理盐水(0.06 mL)。先对大鼠的热刺激缩足反应潜伏期(paw withdrawal thermal latency,PWTL)、机械刺激缩足反应阈值(paw withdrawal mechanical threshold,PWMT)进行行为学测试,随后采血测血糖。 结果:链脲霉素所致高血糖大鼠血糖水平明显升高[(3.43±0.10)mmol/L和(9.03±0.46)mmol/L,P<0.001】,机械刺激缩足反应阈值降低[(12.98±2.19)g和(7.21±1.26)g,P<0.01],而热刺激缩足反应潜伏期未发生明显变化[(13.63±1.65)s和(15.31±0.95)s,P>0.05]。生理盐水组血糖、热痛阈和机械痛阈均未发生明显变化[(4.01±0.25)mmol/L和(3.86±0.22)mmol/L,P>0.05;(13.54±1.08)s和(13.08±0.05)s,P>0.05;(20.06±2.77)g和(19.75±3.18)g,P>0.05]。以上数据均以左足为例。 结论:①中剂量链脲霉素(50μg/kg)腹腔注射,可以成功的诱导出SD雄性大鼠的实验性高血糖(7.0～16.7mmol/L),并且持续12d左右。②链脲霉素所致高血糖大鼠模型血糖水平升高过程中可产生机械痛敏,热痛敏未发生明显变化?

AIM: To study the relationship of blood glucose level to heat pain threshold and mechanical pain threshold in experimental rats with hyperglycemia caused by streptozotocin. METHODS: Twenty male SD rats were randomly divided into two groups: streptozotocin (STZ) group( n = 10) and saline group( n = 10) . Rats in the STZ group were injected with streptozotocin abdominally(50 μg/kg) and those in the saline group were injected with saline 0. 06 mL abdominally. Paw withdrawal thermal latency (PWTL) and paw withdrawal mechanical threshold (PWMT) were tested in behavioral observation, afterwards the blood glucose was measured. RESULTS: The level of blood glucose increased significantly in hyperglycemia rats induced by STZ[(3. 43 ±0. 10) mmol/L and (9. 03±0. 46) mmol/L, P < 0.001] and PWMT decreased[(12. 98 ±2. 19) g and (7.21±1.26) g, P <0.01], however, PWTL didn' t change[(13. 63 ± 1. 65) s and(15. 31 ±0. 95) s, P > 0. 05] . The level of blood glucose, PWTL and PWMT didn' t change remarkably in the saline group [ (4. 01 ± 0. 25) mmol/L and (3. 86 ±0. 22) mmol/L.. P > 0. 05; (13. 54 ± 1. 08) s and (13. 08 ±0.91) s, P > 0. 05; (20. 06 ±2. 77) g and(19. 75 ±3. 18) g, P > 0. 05 ]. All the experiments were progressed on left paw. CONCLUSION: Abdominally injection of moderate dose STZ(50 μg/kg) can successfully induce experimental hyperglycemia(7. 0 - 16. 7 mmol/L)in male SD rats, which will last for -about 12 days. The increasing level of blood glucose in hyperglycemia rats resulted from streptozotocin leads to mechanical hyperalgesia, but not heat hyperalgesia.