The effect of systemic administration on drug uptake at cellular level was evaluated using time-gated fluorescence spectroscopy performed on a murine ascitic tumour model. Mice bearing L1210 leukaemia were injected intraperitoneally or intravenously with 25 mg per kg body weight hematoporphyrin derivative (HpD), 12.5 mg per kg body weight photofrin II (PII), 25 or 5 mg per kg body weight disulp...

Fluorescence and fluorescence excitation spectra of all-trans-2,4,6,8-decatetraene have been obtained in free jets and in inert-gas clusters. In isolated decatetraene, excitation into 1 ‘B, (S, ) results in emission from both S, ( 1 ‘B, + 1 ‘A, ) and S, (2 ‘A, --) 1 ‘A, ) on time scales that are faster than the 10 ns experimental resolution. In clusters, rapid electronic and vibrational relaxat...

Optical methods were tested for measuring the membrane potential changes of mitochondria in isolated perfused rat hearts. Safranin was found to be rapidly taken up by the Langendorff-perfused heart, and after loading with the dye there was practically no washout of the stain during perfusion with Krebs-Ringer bicarbonate solution. Staining with safranin induced the appearance of an intense abso...