An adenylyl cyclase signalling cascade in rat liver after prenatal gamma-irradiation (6,5 Gy)

The adenylyl cyclase signalling cascade was tested in the rat liver of males subjected to the following 0.5 Gy prenatal gamma-irradiation: chronic irradiation during the whole time of embryonic development, single dose irradiation at the 9. day, and at the 15. day of embryogenesis. It was found that the prenatal irradiation resulted in the increase of basal and GTP-simulated adenylyl cyclase activity in all three groups of rats. In contrast, the adenylyl cyclase response to glucagon was essentially reduced. These effects were more pronounced in the chronic irradiated animals. From dose-response curves obtained for adenylyl cyclase activators. Mg==, and ATP we concluded that observed changes in glucagon signalling after single dose and chronic irradiation can be caused by alterations in the Gs protein regulatory cycle. (authors)