Figure 2.

Vascular kinetics of intratracheally instilled ⁵⁹Fe. Control (open squares), bled (closed squares), and iron oxide–exposed (closed circles) rats were intratracheally instilled with 22 μCi/kg ⁵⁹FeCl₃. Data are calculated as percentage of the total instilled dose detected in the blood over the first 4 h. As with ⁵⁴Mn, significantly less ⁵⁹Fe was found in the blood in iron oxide–instilled but more in bled rats (MANOVA, P < 0.05). The kinetics of pulmonary absorption of ⁵⁹Fe was different from ⁵⁴Mn. The percentage of ⁵⁹Fe in the blood was ∼ 10 times more than that of ⁵⁴Mn in normal rats. The shape of the blood kinetic curve was also different with an initial delay in ⁵⁹Fe peak values from 5–15 min compared to ⁵⁴Mn.