Activity of some enzymes involved in "adenylate cycle" in rat embryo cells infected with parvoviruses (X14, H-1).

In rat embryo cell cultures infected with X14 or H-1 parvovirus and in mock-infected cell cultures the activity of some enzymes involved in purine nucleotide interconversion and in "adenylate cycle" was determined. The enzymatic activities have been assayed on 100,000 x g supernatant by spectrophotometric methods, measuring the absorbance variation in U.V. and by radiometric methods, resolving the radioactive products of reaction by TLC on PEI cellulose. The results indicated a decrease of the enzymatic activities that degrade purine nucleosides and nucleotides in infected cells compared to the controls. Some different behaviour patterns showed the enzymes involved in base salvage pathway; adenine phosphoribosyltransferase did not show a significant modification of activity, whereas hypoxanthine (guanine) phosphoribosyltransferase increased slightly in X14 virus-infected cells. The behaviour of the above mentioned enzymatic activities may be considered as a mechanism of purine nucleotide saving, coupled to an active salvage pathway for the synthesis of nucleotides required for the viral replication.