Nitric oxide-mediated hypotension

Patent Granted Macrophages, certain cells of the immune system, produce nitric oxide in order to kill invading bacteria. In this case, the nitric oxide synthase is inducible NOS. Under certain conditions, this can backfire: Fulminant infection (sepsis) causes excess production of nitric oxide by macrophages, leading to vasodilatation (widening of blood vessels), probably one of the main causes of hypotension (low blood pressure) in sepsis. The inducible isoform of nitric oxide synthase is expressed and produces cytotoxic levels of nitric oxide.