OBJECTIVE To compare sensitivity in typeⅠ hypersensitivity between BN and Wistar rats, and to establish a sensitive and reliable determination system for typeⅠ hypersensitivity. METHODS BN and Wistar rats were sc given ovalbumin (OVA) 10, 20 and 40 μg·kg~(-1) every other day for 5 times and normal control group with sc normal saline. The total immunoglobulin E (IgE) levels in serum were determined with ELISA and the specific IgE levels in serum were determined by passive cutaneous anaphylaxis on the 21st day from the 1st injection. The blood pressure, serum histamine and tryptase levels were determined after challenge on the 22nd day. RESULTSTotal IgE, specific IgE, histamine and tryptase levels in serum significantly increased and blood pressure decreased in OVA 10, 20 and 40 μg·kg~(-1) BN rat groups compared with normal control group, while in Wistar rats these symptoms only appeared in OVA 40 μg·kg~(-1) group. CONCLUSION BN rats are more sensitive than Wistar rats in typeⅠ hypersensitivity. The blood pressure, serum total IgE, specific IgE, histamine and tryptase levels can be used as the important indicators in typeⅠ hypersensitivity.

AIM: To investigate the effect of deafferentation on the expression level of calretinin (CR) in adult Sprague Dawley rat olfactory bulb (OB). METHODS: Adult Sprague Dawley rats were given a single intranasal irrigation with ZnSO_4. A specific period (10, 20, 30 and 60 days, respectively) after the treatment, immunoreactivities of tyrosine hydroxylase (TH) and calretinin of OB were examined by using immunohistochemistry. Down-regulation of TH expression level was regarded as a mark of deafferentation. RESULTS: 10, 20, 30 and 60 days after ZnSO_4 treatment, staining intensity and density of TH-immunoreactive cells of OB significantly reduced and the degree of reduction was correlated with the time of treatment before 30 days, but the result of 60 d was similar to that of 30 d. There was no obvious change in the density of CR-immunopositive cells after the same treatment. CONCLUSION: Expression of CR in adult rat OB was not affected by deafferentation.