SERUM TNF ACTIVITY HAD NO INFLUENCE ON MEGAKARYOCYTIC EMPERIPOLESIS IN THE RAT BONE MARROW

The relationship between megakaryocytic emperipolesis in the bone marrow and lipopolysac-charide (LPS)-induced tumor necrosis factor (TNF) was investigated in adrenalectomized or dexameth-asone (Dex)-treated rats. Adrenalectomized rats were injected LPS intravenously at a single dose of 0.5μg/kg body weight 48 h after the operation, and Dex-treated rats were given LSP at a dose of 0.5mg/kg body weight 1 h after the Dex-treatment. Serum TNF activity markedly increased in the adrenalectomized rats (3279.3units/ml), but reduced in the Dex-treated rats (227.3units/ml) I h after LPS-treatment. Megakaryocytic emperipolesis was not influenced by these treatments 24 h after LPS-administration. Thus, LPS-induced serum TNF activity could not increase megakaryocytic emperipolesis.