The role of cyclic amp in the process of specific hyposensitization

The parenteral administration of a specific allergen produces a local edema due to the liberation of histamine. We have investigated the plasmatic cyclic AMPO in this reaction. A group of allergic patients (36 in all) with asthma or rhinitis or both diseases and with a very positive prick skin test was studied. The level of cyclic AMP was investigated before and after injecting the patients with the specific hyposensitizing extract. The average levels of cyclic AMP in our patients before the injection of the specific extract were 2.6 pmol/ml and this corresponded to the normal levels found in the controls in our laboratory (13.8 pmol/ml). After the injection of the allergen these levels increased by an amount that varied between 0.1 pmol/ml and 33.4 pmol/ml in 61.1% of the cases (p > 0.05). The cyclic AMP decreased by an amount that varied between 0.1 pmol/ml and 16.0 pmol/ml in 38.8% of the patients (p > 0.05).