CALCIUM AND MEMBRANE PERMEABILITY

Publisher Website
Google Scholar
Abstract
Cellular excitability and communication between cells interconnected by gap junctions depend upon the concentration of free ionized calcium, [Ca 2+ ] 0 in the extracellular fluid. In addition, in electrically excitable and non-excitable cells of quite diverse developmental origin and fuction the cytoplasmic calcium concentration, [Ca 2+ ] 1 is now seen to play an increasingly important and fundamental role in the integrated control of membrane permeability and the cellular response to stimulation. Channels of discrete unitary conductance and selectivity activated by an increase in [Ca 2+ ] p are responsible for K + efflux Cl − transfer, and Na + influx, respectively. These channels modulate synaptic transmission, muscle contraction, epithelial ion transport and cellular secretion. In particular, the large conductance K + channel activated by [Ca 2+ ] 1 dispalys a wide spread cellular location and multifunctional role reflecting that of the clacium ion itself. Each aspect of membrane permeability controlled by [Ca 2+ ] 0 and [Ca 2+ ] 1 is considered here from the standpoint of cellular mechanism, physiological function and pharmacological significance.

This publication has 0 references indexed in Scilit: