Fig. 2.

The effect of intradermal CRH on extravasation in NT−/− mice. NT+/+ (A) and NT−/− mice (B) were anesthetized with an i.p. injection of ketamine/xylazine, and the fur on the back was shaved. The mice were injected via the tail vein with 0.2 ml of 1% Evans blue. Ten minutes later, 0.05 ml of saline, compound 48/80 (10 μg/ml), CRH (1 μM or 10 μM), or NT (0.1 or 1 μM) was injected. The animals were killed 10 min later by decapitation. The skin was removed, turned over, and photographed. (C) Evans blue was extracted by incubation in N,N-dimethylformamide, and the concentration was calculated from a standard curve. CRH-induced permeability (yellow circles) is reported as a ratio of normal saline (saline) to control for interanimal variability (∗, P = 0.036, n = 3). (D) Mast cell number and skin histamine content were determined in mouse skin isolated from C57BL/6, NT+/+, and NT−/− mice (n = 2; three sections for each). Skin samples were isolated and either sectioned, adhered to slides, and stained with toluidine blue for mast cell counts or homogenized in PBS for histamine analysis.