title: Effects of L-lysine and L-arginine on in vitro replication of feline herpesvirus type-1.
abstract: OBJECTIVE
  To determine the effects of various concentrations of L-lysine and L-arginine on in vitro replication of feline herpesvirus type-1 (FHV-1).
  
  
  METHODS
  Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727.
  
  
  METHODS
  Uninfected CRFK cells or CRFK cells infected with FHV-1 were cultured in Dulbecco's modified Eagle's medium or in 1 of 7 test media containing various concentrations of lysine and arginine. Viral titer and CRFK growth rate were assessed in each medium.
  
  
  RESULTS
  Media depleted of arginine almost completely inhibited viral replication, whereas 2.5 or 5.0 microg of arginine/ml of media was associated with a significant increase in FHV-1 replication. In media with 2.5 microg of arginine/ml, supplementation with 200 or 300 microg of lysine/ml reduced viral replication by 34.2 and 53.9%, respectively. This effect was not seen in media containing 5.0 microg of arginine/ml. Growth rates of CRFK cells also were suppressed in media containing these concentrations of amino acids, but they were not significantly different from each other.
  
  
  CONCLUSIONS
  Arginine exerts a substantial growth-promoting effect on FHV-1. Supplementation of viral culture medium with lysine attenuates this growth-promoting effect in media containing low concentrations of arginine. Analysis of data from this study indicates that high concentrations of lysine reduce in vitro replication of FHV-1 but only in media containing low concentrations of arginine. Clinical trials will be necessary to determine whether supplemental administration of lysine, with or without arginine restriction, will be useful in the management of cats with FHV-1 infections.
authors.affiliation: Department of Veterinary Medicine, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Maggs
authors.forename: B K
authors.initials: BK
authors.lastname: Collins
authors.forename: J G
authors.initials: JG
authors.lastname: Thorne
authors.forename: M P
authors.initials: MP
authors.lastname: Nasisse
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002415:Cats; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D007668:Kidney; D008239:Lysine / Q000494:pharmacology*; D018140:Varicellovirus / Q000187:drug effects / Q000502:physiology*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D003470:Culture Media; D001120:Arginine; D008239:Lysine