Metabolism of Two Valence States of Inhaled Antimony in Hamsters

Abstract

The metabolism of inhaled trivalent and pentavalent antimony in Syrian hamsters was investigated. Two groups of hamsters, 20 in the first and 34 in the second, were exposed by inhalation to aerosols of 124Sb-tartrate complex in the trivalent and pentavalent states, respectively. With either aerosol, 90% of the initial whole-body activity was cleared rapidly, and the remaining activity was retained with a half-life of 16 days. Tissue distribution, studied by serial sacrifice, indicated that antimony accumulated mostly in liver, skeleton, and pelt. Except on day 0 postexposure, activity in the liver was higher after inhalation of the trivalent than of the pentavalent 124Sb; an opposite pattern was seen with the femur (skeleton). In the blood, trivalent antimony was concentrated in the RBC's at all sampling times, whereas pentavalent 124Sb concentrations were greater in the plasma than in the RBC in the first blood samples at 2 hours postexposure. In the 24-hour blood sample, however, pentavalent 124Sb also concentrated in the RBC. When the two forms of 124Sb-tartrate complex were introduced into the GI tract of hamsters via stomach tubes, only small amounts of either compound were absorbed.