Pa TTTNT] ] 1000 ba 35 lOO mg ° ° rp Plasma ‘ ° PTT Percent Injected Dose Per Gram Calcium E E x r Whole body - retention Dog A22B Ozage 8 mt. Bg x xsage 9 yr. “Ca ne i Oe eo, «+ hy . Tee . 10k 10“ ° E po*L .01 0 al wt pt 1.0 et 10 100 TIME IN DAYS 1000 Iria. 33.—The plasma specific activity and the whole body retention of “*Ba and **Ca given intravenously into a single beagle ¢ dow, but at two widely different ages. “Ba was administered when the animal was 8 months of age and “{Ca when the animal was inction 9.2 vears of age. n and vs. 8.5 aurves J2 to 3 and I(T) ‘ed in ations from ected TOXIe dog oring 1 for were m to s for ormi576. reent itted Tum, Dogs allafrom 3 ml samples of whole blood were dissolved in liquid scintillation vials using hydroxide of hyamine and 10 ml each of absolute ethanol and scintillation solu| tion. The vials were then counted against aliquots of the *%Ba injection solution (dissolved in the same | manner as the plasma) in a Packard Tri-Carb liquid scintillation spectrometer system, Model 3002. Quench- ing was controlled by gain adjustments and obser- vations of the spectrum shift through simultaneous two-channel counting with one narrow and one wide window opening. These observed values are also listed in Table 9 and plotted in Figure 32. Urine Samples Urine samples were wet ashed with concentrated HNOs and then diluted up to volume in volumetric flasks. Three-milliliter aliquots from each sample taken from Dog 576 or A22B were sealed in glass vial and counted in the same Nal(Tl) well counter muffle furnace, dissolved in concentrated HNOs, trans- ferred to volumetric flasks, and diluted to volume. Ali- quots from the prepared samples from the appropriate dog were either sealed in glass vials and gamma counted in the well counter or dissolved in liquid scintillation solution and counted in the liquid scintillation spectrometer. All fecal and urinary excretion rates (percent of injected dose per day) are summarized in Table 10. Bone Determinations The bone specimens were air dried, weighed, placed in separate preweighed crucibles, ashed overnight in a muffle furnace at 750° C, reweighed to determine the ash weight of each sample, dissolved in 2N HCl, and then transferred to volumetric flasks. Five long bones (a femur, tibia, humerus, radius, and ulna) from Dog 576 and the left femur from each of the other dogs aliquots of the wet ashed urine samples from Dogs were cut into five pieces, which were coded as proximal end, proximal shaft, mid-shaft, distal shaft, or distal tion vials and counted in the liquid scintillation coun- other samples, appropriate aliquots were either sealed that was used for the plasma clearance studies. Smaller A22C and A22D were transferred to liquid seintillater, Fecal Samples All fecal samples were placed in separate porcelain crucibles, heat dried, ashed overnight in a 600°C end prior to weighing and ashing. As was done with the in glass vials and counted in the well counter or dis- solved in scintillation solution and counted in the liquid scintillation counter. The observed values, listed in Table 11, were calculated by comparison with the standards made from theoriginal injection solution.