priority journal nonhuman 66 article 64 controlled study 60 nitric oxide synthase 54 Animals 50 animal experiment 48 nitric oxide 48 animal tissue 46 enzyme activity 42 Nitric Oxide Synthase 36 animal model 34 female 34 mouse 34 Female 32 protein expression 32 Mice 28 male 28 signal transduction 26 Male 24 Nitric Oxide 22 rat 22 animal cell 18 Humans 16 Mice, Inbred BALB C 16 Signal Transduction 16 Nitric oxide 14 Nitric oxide synthase 14 Rats 14 enzyme activation 14