Spleen containing arsenic

Animal tissues usually contain low levels (<0.3 mg As/kg fresh weight) of arsenic. After the administration of arsenicals, these levels are elevated, especially in liver, kidney, spleen, and lung and several weeks later, arsenic is translocated to ectodermal tissues (hair, nails) because of the high concentration of sulfur-containing proteins in these tissues. 

Arsenic is bound in serum to protein (O]-globulin) and in erythrocytes to the globin part of hemoglobin. Normally the ratio of erythrocyte to plasma arsenic level is 3 1. Arsenic leaves the intravascular space within 24 hr. The blood-brain barrier is hardly penetrated by inorganic forms. Arsenic is stored first in liver (which contains proteins with SH groups), kidney, spleen, and lung [8,9,12,19,39]. 

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