| Popis: |
The Ca2+ channels are classified into: (1) voltage-gated Ca2+ channel, (2) inositol 1,4,5-triphosphate (IP3)-activated Ca2+ channel, (3) ryanodine-receptor (RyRs) Ca2+-release channel, (4) store-operated Ca2+ (Ca2+-release-activated Ca2+ (CRAC)) channel, and (5) transient receptor potential (TRP)-related Ca2+ channel. The cytosolic Ca2+ has function as a regulator of various enzymes and plays an important role as an intracellular second messenger of various hormones in tissues such as the lung. Ca2+ enters into the cytosolic space via several types of Ca2+ channels such as voltage-gated Ca2+ channels across the plasma membrane and is also released into the cytosolic space from intracellular organelles such as endoplasmic reticulum via Ca2+-release channels associated with IP3 and RyRs receptors. Ca2+ also enters into the cytosolic space through CRAC channels triggered by emptying of intracellular Ca2+ stores so-called capacitative Ca2+ entry. The molecular basis of the CRAC channel would be the TRP-related Ca2+ channel. These channels cooperatively regulate the cytosolic Ca2+ concentration ([Ca2+]c) in the lung. Regulation of the [Ca2+]c maintains cell function in the lung such as contraction of smooth muscles, cytokine secretion, ion channel activity etc. On the other hand, disorders of these channels might cause pathogenesis of lung function such as lung edema. |
