Previous results from our laboratory demonstrate that nicotine, via smoking, nasal spray, or transdermal patch, modulates levels of nitric oxide (NO) in plasma. Experiments were designed to determine whether or not nicotine affects plasma nitric oxide through transcription or activity of the enzyme endothelial NOS (ecNOS). ecNOS was isolated from aortic endothelial cells of untreated dogs. mRNA was extracted from the aortic endothelial cells of untreated dogs or dogs treated for five weeks with transdermal nicotine (11 mg/day or 44 mg/day). Activity for NOS (measured as pmol L-[3H] citrulline produced/mg protein/hr) was determined in the absence or presence of nicotine (10-6 to 10-3 M). mRNA for ecNOS was transcribed to c-DNA by reverse transcriptase and quantified using a competitive polymerase chain reaction (PCR). Nicotine increased NOS activity in vitro in a dose-dependent fashion. Nicotine treatment for five weeks did not affect relative quantities of mRNA for ecNOS. Those data demonstrate for the first time a direct effect of nicotine on NOS activity. Furthermore, transdermal nicotine at concentrations used for smoking cessation in humans does not affect transcription of ecNOS endothelial cells in dogs.
|Original language||English (US)|
|State||Published - Mar 20 1998|
ASJC Scopus subject areas
- Molecular Biology