Fig. 7. Desensitisation of endogenous AM and CGRP receptors in endothelial cells. The dynamics of desensitisation of endogenous AM and CGRP receptors in hDMVECs was investigated using an Akt phosphorylation (Akt-P) assay to determine Akt activity. In control groups, cells were exposed to 100 nM AM (AM, lanes 2-4) or CGRP (CGRP, lanes 11-13) for indicated times. In pretreatment groups (Pretreatment with AM or Pretreatment with CGRP; -/+ indicate if pretreatment was performed), cells were exposed to 100 nM AM (lanes 5-9) or CGRP (lanes 14-18) for 15 minutes, and then to a ligand-depleted medium for a further 30 minutes. In pretreatment groups, cells were then re-challenged with either the same agonist (100 nM) (lanes 5-8 for AM, and lanes 14-17 for, respectively) or reciprocal agonists (100 nM) (CGRP for AM-pretreated cells, lane 9; and AM for CGRP-pretreated cells, lane 18) to examine receptor desensitisation. VEGF-treated cells (10 ng/ml for 10 minutes; lane 10) were used as a positive control.