Poly(A) polymerase activity in murine serum. Elevation in animals with proliferative changes.

Sera of normal rats contain polynucleotide adenylyltransferase [poly(A) polymerase] activity. The enzymatic activity has been optimized with regard to primer concentration, ion requirements, kinetics, and protein. Results based on inclusion of inhibitors in the assay system show that the enzyme is poly(A) polymerase. High levels of the enzymatic activity were prevalent in sera of (a) BUF/SimfBR rats bearing sc transplanted hepatomas; (b) Sprague-Dawley rats with hepatoma cells grown in ascites; (c) partially hepatectomized Sprague-Dawley rats; and (d) MRL/lpr mice, which are in a massive lymphoproliferative autoimmune state.