FIG. 8.

Oxidation of thiols in coronary arteries. We investigated the modification of thiol oxidation with ACh (1 μM) or DTT (0.1 μM) in the isolated coronary arteries. Total or extracellular thiols were labeled with either monochlorobimane (MCB) (20 μM, A) or monobromotrimethyl ammoniobimane (MBB) (20 μM, B), respectively. Upper panels show fluorescent images of total reduced or extracellular reduced free thiol groups, and the lower panels show the summary data of fluorescent intensity (in arbitrary units) in isolated coronary arteries. A decrease in fluorescence indicates thiol oxidation with less binding of either fluorochrome. Fluorescence from MCB or MBB was decreased (increased thiol oxidation) in SMP30 KO mice compared to those of the WT mice. Ach decreased the MCB signal in the coronary arteries of the WT mice. Fluorescence to either indicator increased after administration of DTT (0.1 μM). Decrease of the fluorescent intensity was greater in MCB than in MBB of the SMP30 KO mice, indicating the effect on intracellular thiol oxidation. The values were expressed as means±S.E.M., n=10, each. *p<0.01, **p<0.05 versus without any treatment of WT mice. ^#p<0.01, ^##p<0.05 versus without any treatment of SMP30 KO mice.