Gene expression of nAChR subunits in HMVEC, HPAEC, HUVEC and HREC were assessed by Real-time PCR. The ct values for nAChR subunits were normalized using ct values obtained in parallel for 18S mRNA. Subsequently, these values were expressed as relative transcript levels by comparison to those values determined for HMVEC. Endothelial mRNA was detected for each of the known mammalian nAChR subunits with the exception of α2, α4, γ and δ in each of the four different types of endothelial cells. The data represent the mean of 3 different experiments carried out in triplicate with error bars showing SEM.