Effect of whole-body irradiation with X-rays on [Ca2+]i response to Con A in splenocytes

Objective: To elucidate the possible mechanism of immunodepression following whole body irradiation (WBI) with X-rays intracellular free Ca2+([Ca2+]i) response to Con A in splenocytes of mice after WBI was studied. Method: Fluorescent indicator fura-2 was used to assess the changes of [Ca2+]i response to Con A in splenocytes of Kunming mice following WBI with X-rays. Results: WBI with 0, 0.5, 1.2, 4, and 6 Gy X-rays, respectively, could inhibit dose-dependently mitogen Con A-stimulated [Ca2+]i elevation and prolong the time of Con A-stimulated [Ca2+]i elevation to a peak level in splenocytes of mice 24 h after irradiation. Time course of 2 Gy WBI with X-rays indicated that inhibition of Con A-stimulated [Ca2]i increase in splenocytes began at 2 h, reached the lowest value at 24h, and slightly recovered at 5d after WBI. Conclusion: Immunodepressive effect of ionizing radiation is associated with inhibition of [Ca2+]i mobilization in T lymphocytes