QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 2. The enhancing effects of antimycin A or 2-hepthyl-4-hydroxyquinoline (HQNO) are mediated by inhibition of electron transport through complex III and are independent on the accumulation of mtCa²⁺. (A) Representative microscope images (magnification 400x) of cells pre-loaded with Rhod-2 AM and MitoTracker Green and then treated for 10 minutes with 0 or 200 µM peroxynitrite. In the merged image (overlay) regions containing both Rhod-2 and MitoTracker Green fluorescence appear yellow. (B) Rhod 2-AM pre-loaded cells were first treated for 5 minutes with 20 µM ryanodine (Ry), subsequently exposed for 3 minutes to peroxynitrite (40 or 200 µM) and finally incubated for a further 7 minutes in the absence or presence of 1 µM antimycin A or 10 µM HQNO. Fluorescence was then quantified as detailed in the Materials and Methods. Results represent the means ± s.e.m. calculated from three to five experiments. ^*P<0.001 compared with untreated cells (unpaired Student's t-test). (C) Permeabilized cells were exposed for 10 minutes to 200 µM peroxynitrite (200), or 40 µM peroxynitrite/1 µM antimycin A (40 + Antimycin A), in the absence or presence of 10 µM ethylene glycol-bis(-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA), 200 nM ruthenium red (RR), 100 µM LaCl₃, 20 µM Ry, 0.5 µM rotenone, 5 µM myxothiazol or 10 U/ml catalase (enzymatically active or heat-inactivated). The DNA cleavage induced by peroxynitrite in the absence or presence of antimycin A was also assessed in respiration-deficient (RD) cells. The level of DNA single-strand breaks was measured immediately after the treatments. Results represent the means ± s.e.m. calculated from three to five experiments. ^*P<0.001 compared with levels in cells exposed to peroxynitrite alone or associated with antimycin A (unpaired Student's t-test).

Return to article