Ebook: Taurine 4: Taurine and Excitable Tissues

Mitochondria from mammalian tissues possess an elaborate system for 2+ 2+ transporting Ca across their inner membrane which consists of Ca import, 2+ via the Ca uniporter, in response to the mitochondrial membrane 2+ + potential ?? and of Ca release by an antiport system in exchange for H + 9,23 or Na (see Fig. l) . Because the uniporter is dependent upon the external 2+ 2+ 2+ 2+ Ca concentration ([Ca ]), mitochondria accumulate Ca until the [Ca ] o o 2+ decreases to the level at which the uniporter activity balances the Ca efflux. 2+ The [Ca ] at which the uniporter and efflux activities are equal is defined o the “setpoint” andcorresponds to values between 0.3-3µM. 2+ Figure 1. The Ca transport system of the inner membrane of mammalian mitochondria. U, + 2+ + + uniporter. I, Na -independent efflux mechanism or Ca /2H exchanger. D, Na -dependent 2+ + efflux mechanism or Ca /2Na exchanger. PTP, permeability transition pore. FP, 11 flavoprotein. ?? membrane potential. ? pH gradient. Adapted from .

---

This is one of two volumes which together comprise about forty papers coming from the most outstanding contributions to the fourth European Quantum Systems in Chemistry and Physics workshop held in Marly, France, in 1999. These books cover a very broad spectrum of scientific research work from quantum-mechanical many-body methods to important applications and computational developments, and from atoms and molecules to condensed matter. This second volume is subtitled Advanced Problems and Complex Systems and covers the following topics: response theory, reactive collisions and chemical reactions and condensed matter. The first volume is subtitled Basic Problems and Model Systems, which includes the following topics: density matrices and density functionals, electron correlation effects, relativistic formulations and effects, valence theory and nuclear motion.