Distribution and kinetics of injected nickel in the pregnant rat.

Radioactive nickel (Ni) was injected intraperitoneally both carrier-free and in 4 mg/kg body weight of Ni as NiCl2 doses in control and pregnant rats on days 12 and 19 after impregnation. The time-course of disappearance of radioactivity from the tissues and blood of the rat was determined, as well as the degree of incorporation of radioactivity from the injected doses. The maximal uptake of the metal 15 min after injection corresponded to kidney uptake, followed by pancreas, blood plasma and then all other target organs studied. The presence of cold nickel resulted in higher uptake of the metal without much change in the proportion of distribution between tissues. The kinetics of disappearance was similar in all tissues and was little affected by pregnancy, with mean half-lives of about 3-5 h irrespective of doses.