Radiation-induced Changes in Production of Prostaglandins F_2α, E, and Thromboxane B₂ in Guinea Pig Parenchymal Lung Tissues

Summary

At 1 hour to 4 days after unilateral exposure of guinea pigs to a single dose (0·5, 1·5, or 3·0 Gy) of gamma-radiation, changes were detected in prostaglandin and thromboxane concentrations in parenchymal lung tissues. At 1–3 hours after exposure, tissue levels of PGF_2α, PGE, and thromboxane B₂ were significantly elevated in animals receiving 3·0 Gy, with the magnitude of alteration revealing a radiation dose effect. By 24 hours, tissue prostaglandin and thromboxane levels returned to near control values. Lung tissue synthesis of prostaglandins in response to H-1 receptor stimulation by the exogenous addition of histamine revealed similar radiation dose effects. The carboxylic acid ionophore A23187, exogenously applied to lung tissues, revealed a transient peak of increased sensitivity to ionophore stimulation for TxB₂ synthesis at 24 hours and for PGF_2α at 72 hours post-irradiation. The data suggest that significant alterations in prostaglandin and thromboxane concentrations in parenchymal lung tissues occur following irradiation, in a dose-dependent manner, and that altered responsiveness to H-1 receptor stimulation and divalent cation transport also occur.