Extracts of canine liver inhibited growth of infectious canine hepatitis (ICH) virus, a canine adenovirus. Purified extracts from mammalian, but not avian, liver tissue contained the inhibitor, and evidence is presented that the inhibitory factor is the enzyme arginase (arginine ureohydrolase). This study further emphasized the need for arginine in adenovirus growth and may explain some of the difficulties in isolating small amounts of ICH virus from suspensions of liver.
MATERIALS AND METHODSCells. Tube cultures of DK cells were prepared according to standard procedures. Inoculation medium was Earle saline solution that contained 5% heated 348