Intracellular photorelease of Ca2+ demonstrated the presence of Ca2+-activated K+ channels in smooth muscle cells isolated from different locations of the rat pulmonary arterial tree. However, cell-free patch studies revealed marked differences in K+ channel distribution. In the main pulmonary artery the most frequently observed K+ channel was a ~245pS conductance Ca2+- and ATP-activated (K(Ca),ATP) channel. In small pulmonary arteries two K+ channel types predominated: the K(Ca),ATP channel and a ~185pS conductance K+ channel insensitive to intracellular Ca2+, ATP and voltage. This difference in K+ channel distribution may highlight a more complex regulatory mechanism for controlling membrane potential in small pulmonary arteries,reflecting their physiologically more important role in governing pulmonary vascular reactivity.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 1995|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology