Arginine vasopressin-induced nitric oxide content changes in cultured cardiac fibroblasts and its relation to nuclear factor-κB

To investigate the changes in the nitric oxide (NO) contents, nitric oxide synthase (NOS) activity and inducible nitric oxide (iNOS) mRNA expression in arginine vasopressin (AVP)-induced cardiac fibroblasts (CFs) in vitro and its relation to nuclear factor-κB (NF-κB), CFs were isolated by trypsin digestion method. Nitric acid reductase method, spectrophotometry, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence-interactive laser cytometer techniques and Western blotting were used respectively to detect NO contents, NOS activity, iNOS mRNA expression and the activation of NF-κB in CFs. AVP increased NO contents, NOS activity and iNOS mRNA expressions in a concentration-dependent manner; NF-κB was activated and mobilized from cytoplasm to nucleus in AVP-induced CFs; PDTC, one of the inhibitors of NF-κB, could inhibit aforementioned increments. It is suggested that the increases in NO contents, elevation of NOS activity and increment of iNOS mRNA expression may be mediated through NF-κB activation pathway in cultured CFs induced by AVP, and that NF-κB is involved in the occurrence and development of myocardial fibrosis.