FIGURE 1.

Effects of angiotensin I (A-I), angiotensin II (A-II), A-II Type 1 receptor blockers (ARB) and angiotensin-converting enzyme inhibitors (ACEi) on angiotensin-converting enzyme 2 (ACE2) expression in pulmonary and adrenal cells. a, b) A549 and c, d) Calu-3 cells were cultured in Eagle's Minimum Essential Medium and Dulbecco's Modified Eagle Medium (DMEM), respectively, with 10% fetal bovine serum until confluence. e) HAC15 cells were cultured in DMEM:F12 (1:1) supplemented with 10% Cosmic Calf serum until confluence. Cells were then incubated in serum-deprived medium with 0.1% serum for 24 h, after which the medium was replaced with fresh medium containing 0.1% serum with or without ARB or ACEi for 30 min. A-I or A-II were added to the medium, and cells were collected after 3 h of incubation for subsequent quantitative PCR assay. Statistical analyses were performed by one-way ANOVA; no significant differences were observed in A549 cells or Calu-3 cells (p>0.05). The difference was analysed by t-test in HAC15 cells: A-II stimulation significantly increased ACE2 expression (p<0.05). Results were expressed as fold change relative to unstimulated control cells. In each experiment, samples were assayed in triplicate. Three independent experiments were performed. Los: losartan; Val: valsartan; Lis: lisinopril; Cap: captopril.