Beat dependent alteration of Ca2+-activated Cl- current during rapid stimulation in rabbit ventricular myocytes

The role of anoctamin 1 in liver disease

Liver diseases include all types of viral hepatitis, alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), cirrhosis, liver failure (LF) and hepatocellular carcinoma (HCC). Liver disease is now one of the leading causes of disease and death worldwide, which compels us to better understand the mechanisms involved in the development of liver diseases. Anoctamin 1 (ANO1), a calcium-activated chloride channel (CaCC), plays an important role in epithelial cell secretion, proliferation and migration. ANO1 plays a key role in transcriptional regulation as well as in many signalling pathways. It is involved in the genesis, development, progression and/or metastasis of several tumours and other diseases including liver diseases. This paper reviews the role and molecular mechanisms of ANO1 in the development of various liver diseases, aiming to provide a reference for further research on the role of ANO1 in liver diseases and to contribute to the improvement of therapeutic strategies for liver diseases by regulating ANO1.

Calcium-activated CL- current is enhanced by acidosis and contributes to the shortening of action potential duration in rabbit ventricular myocytes

Ca2+-activated Cl- current (I(Cl(Ca))) is activated by Ca2+ transient via Ca2+-induced Ca2+ release from sarcoplasmic reticulum in cardiac myocytes and is supposed to play an important role in the repolarization of action potential. It is not well understood, however, how I(Cl(Ca)) is modulated to affect action potential in normal or pathological conditions. In this study we examined the effects of external acidosis on I(Cl(Ca)) and action potential. A whole-cell patch clamp was performed to record action potential and I(Cl(Ca)), using isolated rabbit ventricular myocytes. In the standard solution at pH 7.4, action potential duration (APD) was markedly prolonged by lowering the extracellular Cl- concentration ([Cl-](o)) or by applying an anion channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). In the low pH solution at 6.4, APD was markedly shortened and the amplitude of I(Cl(Ca)) was increased at all membrane potentials. At pH 6.4, the apparent steady-state inactivation curves of I(Cl(Ca)) were shifted to more positive potentials compared with those at pH 7.4, but no change in inactivation occurred at a holding potential of -60 mV. The apparent activation curves were not changed between the two sets of conditions. When I(Cl(Ca)) was inhibited at low pH, early afterdepolarizations and triggered activities were induced. The amplitude of I(Cl(Ca)) was suggested to be enhanced by the external acidosis, which may have prevented the induction of early afterdepolarization or triggered activity.