Fig. 5
Expression of α1A-adrenoceptors is reduced in breast cancer feed arteries compared to matched control arteries. a Concentration-dependent inhibition of norepinephrine-induced vasocontraction by the α1-adrenoceptor antagonist prazosin (n = 6). The curves are the results of least-squares fits to sigmoidal functions. b, c Original images of labelling achieved with 1 μmol/L BODIPY™ FL prazosin in control arteries and breast cancer feed arteries. The second image within tunica media—identified relative to the autofluorescent internal elastic lamina—was extracted from Z-stack series (1-μm steps) and used for quantification. Low (b) (scale bar 50 μm) and high (c) (scale bar 10 μm) magnification images are shown. c The light intensity is equally enhanced for control and cancer feed arteries in order to make the autofluorescence of vascular smooth muscle cells (VSMCs) visible and confirm the stronger prazosin binding to VSMCs in control arteries compared to cancer feed arteries. d Relative fluorescence-labelled areas in the arterial media of breast cancer feed arteries and matched control arteries (n = 5). Data were compared by the paired two-tailed Student’s t test. e Expression of messenger RNA (mRNA) for α1-adrenoceptors in breast cancer feed arteries relative to matched control arteries (n = 12). The expression levels for the α1-adrenoceptors were normalized to the expression of the transferrin receptor. Distributions were compared to a hypothetical mean of 1 by the one-sample Student’s t test. *P < 0.05, **P < 0.01, ***P < 0.001, NS: not significantly different vs. control or as indicated