Oral administration versus intra-peritoneal injection of Pb affects its concentration in selected rat tissues

During studies in our laboratory, a significant difference in Pb concentration was observed depending upon Pb administration: rats that were given Pb by intra-peritoneal injection showed a higher concentration of Pb and smaller relative errors compared to their oral counterparts. The relative percent changes in several tissues between oral and IP groups were calculated to determine whether Pb concentrations were statistically significant or not.