Fig. 1.
The inhibitory effect of calcium voltage-gated channel subunit alpha1 C (CaV1.2) specific antagonists on mast cell (MC) activation in vitro. (A) The half-maximal inhibitory concentration (IC50) of nicardipine, verapamil, nimodipine (Nim), amlodipine, nifedipine, and felodipine on β-hexosaminidase release in laboratory of allergic diseases 2 (LAD2) cells was detected. Among six CaV1.2 antagonists, Nim showed the best inhibitory effect, and the IC50 was 18.23 ± 1.12 μM. Hill value: nifedipine, 1.2731; verapamil, 0.7337; Nim, 3.3493; amlodipine, 0.7988; nicardipine: 3.6284; and felodipine, 2.4668. (B) LAD2 cell viability with Nim treatment. (C) The effect of Nim on MCs β-hexosaminidase release rate induced by various Mas-related G protein-coupled receptor-X2 (MrgX2) agonists: compound 48/80 (C48/80), substance P (SP), ciprofloxacin (Cipro), and sinomenine (Sino). (D) The effect of Nim on LAD2 cells and murine peritoneal MCs (MPMCs) release induced by C48/80. (E) The effect of Nim on LAD2 cells (left) and MPMCs (right) Ca2+ influx induced by C48/80. Experiments were repeated three times. Data are presented as the mean ± standard error of mean (SEM) and were analyzed using one-way analysis of variance (ANOVA) test. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001, compared between experiment groups and vehicle; ###P < 0.001, compared between experiment and negative control (NC) groups. TNF-α: tumor necrosis factor; CCL-2: C–C motif chemokine ligand 2; RFU: relative fluorescence unit.