Phosphates in red cells of two lungfish: the South American, Lepidosiren paradoxa, and the African, Protopterus aethiopicus

Abstract

Measurements were made of water-soluble phosphates in red blood cells of two lungfish, the South American, Lepidosiren paradoxa, and the African, Protopterus aethiopicus. Lepidosiren was studied on the research vessel Alpha Helix on the Amazon River and P. aethiopicus was obtained at Lake Victoria, Kenya. The red cells of both species contained moderate amounts of ATP and GTP, with the former predominant. Also present were higher concentrations of the uridine mononucleotides, UDP and UTP, than had been seen in other kinds of red cells. Of special interest was the discovery in red cells of both fish of a previously unreported inositol diphosphate. No other inositol polyphosphates were found. The red cells of P. aethiopicus had two phosphate compounds (one an adenine nucleotide), which are still unidentified