大鼠烫伤痛模型的建立：恒温电热仪

Establishment of scald-induced pain model in rats： a constant-temperature electrical scald instrument

目的 利用恒温电热仪建立大鼠烫伤痛模型.方法 清洁级健康雄性SD大鼠36只,体重200～ 250 g,采用随机数字表法分为4组（n=9）：对照组（C组）、烫伤5 s组（S5组）、烫伤10s组（S10组）和烫伤15 s组（S15组）.S5组、S10组和S15组分别接触恒温电热仪热板（85℃）5、10、15s,C组接触热板（室温）10s.分别于处理前1 d（T0）、处理后1、3、5、7和14 d（T1-5）时测定机械痛阈和热痛阈,于处理即刻及处理后24 h时观察并记录大鼠的全身状况、创面色泽及边缘形状,于处理后24 h时随机处死3只大鼠,取足底皮肤行病理学检查.结果 与C组比较,S5组T1-2时热痛阈、T1-3时机械痛阈降低,S10组T1-4时热痛阈和机械痛阈降低（P＜0.05）.S15组T1-5时热痛阈＞25 s,机械痛阈＞30 g.S10组足部肿胀明显,烫伤部位水疱形成,损伤程度较S5组和S15组加重.结论 利用恒温电热仪85℃烫伤10s成功建立大鼠烫伤痛模型.

Objective To establish a scald-induced pain model using a constant-temperature electrical scald instrument in rats.Methods Thirty-six pathogen-free male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into 4 groups （n =9 each） using a random number table： control group （group C）, scald for 5 s group （group S5）, scald for 10 s group （group S10）, and scald for 15 s group （group S15）.The rats were anesthetized with intraperitoneal chloral hydrate.In S5, S10 and S15 groups, the plantar surface of the left hindpaw of rats were exposed to a constant-temperature electrical scald instrument （85 ℃） for 5, 10 and 15 s, respectively.The plantar surface of the left hindpaw of rats was exposed to an electrical scald instrument （room temperature） for 10 s in group C.At 1 day before treatment （T0）,and 1, 3, 5, 7 and 14 days after treatment （T1-5）, the mechanical and thermal pain thresholds were measured.Immediately after treatment, and at 24 h after treatment, the total body condition, wound color, and shape of the margin of the wound were observed and recorded.At 24 h after treatment, 3 rats were randomly sacrificed, and the skin from the plantar surface of the left hindpaw was removed for microscopic examination.Results Compared with group C, the thermal pain threshold at T1-2, and the mechanical pain threshold at T1-3 were significantly decreased in group S5, and the thermal pain threshold,and mechanical pain threshold were significantly decreased at T1-4 in group S10 （P〈0.05）.The thermal pain threshold 〉 25 s, and the mechanical pain threshold 〉30 g at T1-5 in group S15.The swelling in foot was bovious, burn blister appeared, and the degree of damage was aggravated in group S10 compared with S5 and S15 groups.Conclusion The scald-induced pain model is successfully established using a constant-temperature electrical scald instrument in rats.