Dynamics of the changes in the cerebral amounts of cyclic AMP and some prostaglandins during cobalt-60 gamma-radiation-induced brain edema.

The total amounts of cyclic AMP (cAMP), prostaglandin E1 (PGE1) and prostaglandin F2alpha (PGF2alpha) in cerebra have been measured in rats, at constant intervals, up to 18 days after whole body exposure to either a unique moderate dose (500 rads) or a unique lethal dose (750 rads) of cobalt-60 gamma-radiation. The experimental findings indicate that this radiation (i) results in an abrupt short-lasting increase in the amount of cerebral cAMP after a 500 rad-irradiation and a progressive long-lasting increase in its amount after a 750 rad-irradiation, and (ii) induces no change in the normally, existing correlation between cerebral PGE1 and cAMP, but affects deeply the normally existing correlation between cerebral PGF2alpha and cAMP. These biochemical alterations generally parallel the evolution of the radiation-induced brain edema.