Effects of extracellular metabolic acidosis and out-of-equilibrium CO/HCO solutions on intracellular pH in cultured rat hippocampal neurons.

Metabolic acidosis (MAc)-an extracellular pH (pH) decrease caused by a [HCO ] decrease at constant [CO]-usually causes intracellular pH (pH) to fall. Here we determine the extent to which the pH decrease depends on the pH decrease vs the concomitant [HCO ] decrease. We use rapid-mixing to generate out-of-equilibrium CO/HCO solutions in which we stabilize [CO] and [HCO ] while decreasing pH (pure acidosis, pAc), or stabilize [CO] and pH while decreasing [HCO ] (pure metabolic/down, pMet↓).

Capsaicin induces NKCC1 internalization and inhibits chloride secretion in colonic epithelial cells independently of TRPV1.

Colonic chloride secretion is regulated via the neurohormonal and immune systems. Exogenous chemicals (e.g.

Secreted protein acidic and rich in cysteine is a matrix scavenger chaperone.

Secreted Protein Acidic and Rich in Cysteine (SPARC) is one of the major non-structural proteins of the extracellular matrix (ECM) in remodeling tissues. The functional significance of SPARC is emphasized by its origin in the first multicellular organisms and its high degree of evolutionary conservation. Although SPARC has been shown to act as a critical modulator of ECM remodeling with profound effects on tissue physiology and architecture, no plausible molecular mechanism of its action has been proposed.