Transmembrane signalling mechanisms regulating expression of cationic amino acid transporters and inducible nitric oxide synthase in rat vascular smooth muscle cells

The signalling mechanisms involved in the induction of nitric oxide synthase and l-arginine transport were investigated in bacterial lipopolysaccharide (LPS)- and interferon-gamma (IFN-gamma)-stimulated rat cultured aortic smooth muscle cells (RASMCs). The expression profile of transcripts for cationic amino acid transporters (CATs) and their regulation by LPS and IFN-gamma were also examined. Control RASMCs expressed mRNA for CAT-1, CAT-2A and CAT-2B. Levels of all three transcripts were significantly elevated in activated cells. Stimulated CAT mRNA expression and l-arginine transport occurred independently of protein kinase C (PKC), protein tyrosine kinase (PTK) and p44/42 mitogen-activat…