Protection of heart against ischemia-reperfusion injury by ischemic preconditioning and K ATP channel openers is known to involve the mitochondrial ATPsensitive K ؉ channel (mitoK ATP ). Brain is also protected by ischemic preconditioning and K ATP channel openers, and it has been suggested that mitoK ATP may also play a key role in brain protection. However, it is not known whether mitoK ATP exists in brain mitochondria, and, if so, whether its properties are similar to or different from those of heart mitoK ATP . We report partial purification and reconstitution of a new mitoK ATP from rat brain mitochondria. We measured K ؉ flux in proteoliposomes and found that brain mitoK ATP is regulated by the same ligands as those that regulate mitoK ATP from heart and liver. We also examined the effects of opening and closing mitoK ATP on brain mitochondrial respiration, and we estimated the amount of mitoK ATP by means of green fluorescence probe BODIPY-FL-glyburide labeling of the sulfonylurea receptor of mitoK ATP from brain and liver. Three independent methods indicate that brain mitochondria contain six to seven times more mitoK ATP per milligram of mitochondrial protein than liver or heart.

Photodynamic therapy is usually used against malignant and non-malignant tumors. Nowadays, due to resistance of bacterial strains, we are looking for a new antimicrobial strategy to destroy bacteria with minimal invasive consequences. The worldwide increase in antibiotic resistance among different classes of gram-positive and gram-negative bacteria has led to the search for alternative anti-microbial therapies such as antimicrobial PDT (aPDT). Development antimicrobial technology combines a nontoxic compound, called photosensitizer, visible light of the appropriate wavelength, and the generation of reactive oxygen species. In this work, the photosensitizers TMPyP and ZnTPPS4 are investigated for photodynamic and antimicrobial photodynamic therapy. We tested these two porphyrins on two cell lines and two bacterial strains to compare effectiveness. In addition, we applied photosensitizers bound in the complex created with hp-β-cyclodextrin. The light-emitting diodes were used at the doses 0, 1, 5, 10 J/cm(2) for cells and 0, 150 J/cm(2) for bacteria. Tested concentrations for cells and microbes were from 0.5 to 50 μM and from 0.78 to 100 μM, respectively. From this work it can be concluded that TMPyP is a promising compound both in aPDT and in PDT, particularly in contrast to ZnTPPS4, which was efficient only in PDT. Furthermore, the eradication of gram-positive bacteria is possible only with higher concentrations of ZnTPPS4.

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