Fig. 3. Quantitative analysis and comparison of GLUT4 translocation to sarcolemma and transverse-tubule membranes of cardiomyocytes. Average GFP and anti-HA fluorescence intensity was determined from regions representing the sarcolemma and transverse-tubule membrane (as defined in the Materials and Methods). (A) Sarcolemma GFP (black bars) and anti-HA (white bars) signals measured under insulin, contraction and hypoxia stimulation. All fluorescence signals were normalised to the maximum values obtained under insulin stimulation. (B) Transverse-tubules GFP (black bars) and anti-HA (white bars) signals measured under insulin, contraction and hypoxia stimulation. (C) Ratio of anti-HA to GFP signals at sarcolemma and transverse tubules. Error bars are s.e.m. of 24-27 sarcolemma values and 40-90 transverse-tubules values from seven to ten cells per condition, from a single representative experiment. ^*P<0.05 versus basal; ^**P<0.05 versus hypoxia.