Ca ²⁺ Homeostasis in Vascular Smooth Muscle

Abstract

The free intracellular calcium concentration is an important link in the excitation-contraction coupling mechanism of vascular smooth muscle. In this review, some current topics about vascular smooth muscle as regards Ca²⁺ storage, Ca²⁺ release, Ca²⁺ extrusion and Ca²⁺ regulation are discussed. Particular attention is paid to Ca²⁺ mobilized from the sarcoplasmic reticulum, the physiologically important Ca²⁺ reservoir in vascular smooth muscle. This occurs through two Ca²⁺ release channels: the inositol 1,4,5-trisphosphate receptor and the ryanodine receptor; the characteristics, function and control of these two receptors are summarized. Emphasis is also placed on a role of the nucleus as a potential Ca²⁺ storage site.