Normal and atherosclerotic aortas from rats and man have been analyzed by neutron activation to determine changes in the content of Ca, Cd, Co, Cu, Mg, Mn, Se, V, and Zn with the development of degenerative changes. Samples of aortic tissue were weighed, dried at 110°C overnight, and irradiated for 30 min in a thermal neutron flux of 1.8X1012 n/cm2-sec in a TRIGA Mark I reactor. Immediately after irradiation, the samples were wet-ashed in the presence of carriers, the various elements were then radiochemically separated, and the separated fractions were counted by multichannel gamma-ray spectrometry. Definite values, or firm upper limits, for the elements were calculated by computer. With increasing degree of atherosclerosis, the Ca content rose from <350 to 36 000±2000 ppm; Co from undetectable to 0.34 ppm; Mg from <110 to 880 ppm; Mn from 0.34 to 1.26 ppm; and Zn from 37 to 152 ppm. Significant changes could not be detected in Cd, Se, and V; changes in Cu were not consistent. These results are discussed in relation to the pathological changes and to zinc therapy in the treatment of atherosclerosis.
Estimation and Calibration of Thermal Neutron Flux for Neutron Activation Analysis