Role of nitric oxide on the replication of viral haemorrhagic septicemia virus (VHSV), a fish rhabdovirus

In the present work, we have studied the role of nitric oxide (NO) on the r eplication of viral haemorrhagic septicemia virus (VHSV), a virus which pro duces high mortalities in fish aquaculture worldwide and that is known to r eplicate in turbot (Scophthalmus maximus) head kidney macrophages. Viral in fection of turbot kidney macrophages in vitro induced an up-regulation of N O production and we have tested whether this endogenous NO production induc ed by VHSV on macrophages had an antiviral effect using the NO synthase inh ibitor, N-omega-nitro-L-arginine (L- NAME). When L-NAME was added to the VH SV-infected cultures, no increase on VHSV titer was observed, eventhough th e inhibitor was capable of decreasing NO production. When exogenous NO was apported by the nitric oxide donor, glycerin trinitrate (GTN) an antiviral effect on VHSV was observed. The NO donor significantly inhibited VHSV repl ication on a turbot fibroblast cell line (TV-1) and on turbot kidney macrop hages. (C) 1999 Elsevier Science B.V. All rights reserved.