Abstract: Objective To gain sensitive experimental conditions and improve the accuracy of passive cutaneous anaphylaxis(PCA) test through investigating the influencing factors of PCA in SD rats. MethodsHomologous PCA was performed by using SD rats, and were carried out in different experimental conditions(with or without adjuvant, OVA or BSA was taken as allergen, sensitizing doses, sensitizing means, sensitizing times). ResultsHomologous PCA revealed negative reaction without adjuvant, showed positive reaction with adjuvant. According to diameter of dermal Evan's blue spot and the positive reaction rate, the degree of response was as follows: Al(OH)3>DPT vaccine>CFA. The immunogenicity of OVA was superior to BSA in SD rats when Al(OH)3 was added as adjuvant in PCA test. The diameter of dermal Evan's blue spot accreted by increasing sensitizing dose. Intraperitoneal and subcutaneous injection sensitization both could get good response of PCA, and there were no significant deviations between two sensitizing means. There was no obvious impact on PCA response by increasing sensitizing times. ConclusionThe optimal conditions in homologous PCA in SD rats are as follows: SD rats are sensitized with OVA 10mg/rat and Al(OH)3 which is added as adjuvant through subcutaneous injection every other day, three times in all. Blood is gained from abdominal aorta on the tenth day after the last sensitization, and blood serum is gained by centrifugalization. The other SD rats are sensitized with 1mL blood serum by endermic injection, and then, SD rats are stimulated with OVA 10mg/rat with equal volume 5% Evans blue.

Key words: SD rat, PCA, adjuvant