Ketamine inhibits LPS-induced tumour necrosis factor-alpha and interleukin-6 in an equine macrophage cell line Daniëlle P.K. Lankveld, Sarah Bull, Paul Van Dijk, Johanna Fink-Gremmels and Ludo J. Hellebrekers Vet. Res., 36 2 (2005) 257-262 DOI: 10.1051/vetres:2004061