In vivo measurement of NO, and O
in dorsal 14-day old 4T1 subcutaneous tumours in BALB/c mice (50-100 mm
). Symbols: Panels A-C: vertical NO (black circle) and oxygen (white triangle) concentration profiles in 3 different spots of an uninfected tumour; Panels D-F: such profiles in a tumour that was infected intratumourally with the bacteria 24 h prior to the measurement. Amperometric microsensors were used; representative results are presented.