Phosphates in red cells of two South American osteoglossids: Arapaima gigas and Osteoglossum bicirrhosum

Abstract

Water-soluble phosphates of red blood cells of the South American osteoglossid fish Arapaima gigas were measured by ion-exchange column chromatography. Major phosphate components were ATP and GTP with the former predominant. Of special interest was the presence of a large pool of inositol pentaphosphate, hitherto seen only in red cells of birds and turtles. A close relative of Arapaima, another South American osteoglossid, Osteoglossum bicirrhosum, had no inositol polyphosphates in its red cells. This study stemmed from work on the research vessel Alpha Helix on the Amazon River.