[1] Univ Oslo, Oslo, Norway
[2] Oslo Univ Hosp, Inst Clin Med, Dept Pharmacol, Oslo, Norway
[3] Oslo Univ Hosp, Inst Expt Med Res, Oslo, Norway
[4] Queen Mary Univ London, William Harvey Res Inst, Barts & London Sch Med, London, England
[5] Univ Minnesota, Dept Biochem Mol Biol & Biophys, Med Sch, Minneapolis, MN USA