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Treatment of isolated mitochondria with calcium and inorganic phosphate induces inner membrane permeability that is thought to be mediated through a nonselective, calcium-dependent pore. The inner membrane permeability results in the rapid efflux of small matrix solutes such as glutathione and calcium, loss of coupled functions, and large amplitude swelling. We have identified conditions of permeability transition without large amplitude swelling, a parameter often used to assess inner membrane permeability. The addition of either oligomycin, antimycin, or sulfide to incubation buffer containing calcium and inorganic phosphate abolished large-amplitude swelling of mitochondria but did not prevent inner membrane permeability as demonstrated by the release of mitochondrial glutathione and calcium. The release of both glutathione and calcium was inhibited by the addition of cyclosporin A, a potent inhibitor of permeability transition. Transmission electron microscopy analysis, combined with the glutathione and calcium release data, indicate that permeability transition can be observed in the absence of large-amplitude swelling. Permeability transition occurring both with and without large-amplitude swelling was accompanied by a collapse of the membrane potential. We conclude that cyclosporin A-sensitive permeability transition can occur without obvious morphological changes such as large-amplitude swelling. Monitoring the cyclosporin A-sensitive release of concentrated endogenous matrix solutes, such as GSH, may be a sensitive and useful indicator of permeability transition.

Using an automated “aspect ratio method” to evaluate shear-wave anisotropy from earthquakes recorded on arrays of three-component digital seismographs over the Bucaramanga nest of Colombia, the East Rift Zone of Hawaii, and the Phlegraean Fields uplift area of Italy, a shear-wave velocity anisotropy of 4–7% is observed. The anisotropy is attributed to tectonic processes acting either to align anisotropic minerals or to align stress-related cracks. At most fixed seismographs, the polarization of the leading S-phase is consistent from event to event, independent of earthquake location. On a regional basis, the polarization may vary from station to station, but a regional trend is apparent.

We have examined the pyridine and adenine nucleotide status during calcium- and inorganic phosphate-induced permeability transition. Calcium- and inorganic phosphate-induced permeability transition is accompanied by the rapid oxidation of pyridine nucleotides and depletion of ATP and ADP with conversion to AMP. The addition of cyclosporin A, a potent inhibitor of the permeability transition prevented the oxidation of pyridine nucleotides and depletion of ATP and ADP.Copyright 1994, 1999 Academic Press, Inc.