[Formation of inositol triphosphate in lymphocytes of rat spleen in the early stages after x-irradiation].

Abstract

Stimulation of 32P-phosphoinositides turnover and phosphatidylinositol-4,5-biphosphate hydrolysis is observed 6 h after animals X-ray irradiation in a dose 1 Gy. Both mitogenic lectins LPS and PHA (10 mg/ml), but not 0.5 microM A23187 induce inositol phosphates release from endogenous [3H]inositol--phospholipids in lymphocytes. The level of inositol triphosphate is increased within 1-6 h and decreased in 12 h after irradiation. 45Ca2+ influx through lymphocytes plasma membrane is not changed within 3 h, but increases greatly 12 h after exposure. Data obtained indicate that IP3 formation is an early signal for radiation-induced changes in calcium homeostasis.