Biochemical mechanisms of stress-induced impairment of rat T cell mitogenesis

Splenic mononuclear cells isolated from rats exposed to two brief stressors (5 min of restraint or 2 min of footshock) showed a diminished response to the T cell mitogens, concanavalin A and phytohemagglutinin. Cells from these stressed animals also exhibited a diminished response to stimulation with the phorbol ester, tetradecanoylphorbol acetate (TPA), and/or the calcium ionophore, ionomycin. Since stimulation with these latter two agents mimics early signals generated by mitogen surface receptor binding including increased intracellular calcium and protein kinase C activation, the data indicate that stress-related defects in T cell proliferation occur at sites other than or in addition to these early events in cellular activation.