Establishment and evaluation of a guinea pig model of itching / 中国实验动物学报

ABSTRACT

Objective To optimize the optimal doses of histamine and 4-aminopyridine (4-AP) in the establish-ment of guinea pigs models of itching, and to establish a new guinea pig model of itching. Methods The central composite design-response surface method was used to arrange the experiment. In the experiment different pruritus agents were hypo-dermically injection of 0. 5 mL in the depilated area, and the scratching incubation period and scratching number in 30 mi-nutes were counted after the injection. The guinea pig itching model was evaluated by observing the behavioral changes of guinea pigs and measuring the levels of histamine and interleukin-6 in the blood. Results The behavioral experiments found that the scratching frequency in the the combination group was significantly higher than the histamine group and 4-AP group (P<0. 01). The itching latency of the combination group was significantly shorter than that of the histamine group and 4-AP group (P<0. 01). Compared with the control group, the histamine concentrations of the combination group and histamine group were significantly increased ( P<0. 05 or P<0. 01 ) , and the level of the combination group was lower than that of the histamine group (P<0. 05). Compared with the control group, the serum IL-6 concentrations of histamine group, 4-AP group and combination group were significantly higher (P<0. 01 or P<0. 05), and those in the combination group were significantly higher than the histamine and 4-AP groups. Compared with the control group, pathologic examina-tion showed proliferation of inflammatory cells in all model groups, and the reaction of the combination group was more ob-vious. Conclusions The optimal conditions used in this experiment are easy to achieve and have good reproducibility in the establishment of a guinea pig model of itching.