Serum lactate dehydrogenase (LDH) activity following exposures to cadmium and/or 60Co gamma irradiation

A total of 216 male Sprague-Dawley rats were used. Animals were injected IP every 3 days for 29 days for a total of 9 injections with 0, 1.0 or 2.5 mg Cd/kg body wt. Total cumulative doses were 0, 9.0 or 22.5 mg Cd/kg body wt. Twenty-four hrs after the last Cd injection (day 30), each animal was subjected to an acute sublethal total-body exposure of 0, 362 or 543 rads of gamma (60Co) irradiation at a dose rate of 304 rads/min. Eight rats from each of the 9 groups were sacrificed by cardiac exsanguination on post-irradiation day 1, 7 or 21.Radiation alone produced significant elevations of LDH. However, Cd alone or as the co-insult did not produce significant changes in enzymes levels. The molecular basis for the mechanism is not known.