Primary hHSC express the cathecholamine synthesising enzyme dopamine-β-hydroxylase and synthesize/release NE plus EPI to regulate hHSC basal growth in culture.
a) We first established by immunohistochemistry that hHSC expressed dopamine-β-hydroxylase (DBH) (data not shown). HPLC analysis of hHSC conditioned medium showed hHSC release of NE and EPI with NE more abundantly produced than EPI. b) Activated hHSC cultured basally for 48hours with PRZ (10 μM) or PRL (10 μM) singly or in combination significantly had reduced basal proliferation. Proliferation under each treatment condition was normalised to the corresponding serum free control in each experiment; *p<0.05, **p<0.0001, each bar represents mean ±SEM, n = 3.