Cholesterol depletion alters coronary artery myocyte Ca(2+) signalling in a stimulus-specific manner.
Bottom Line: We found that cholesterol depletion caused a selective modification of ion channel function, with whole cell inward Ca(2+) current being unaltered, whereas outward K(+) current was increased, due to BK(Ca) channel activation.There was also a significant decrease in cell capacitance.These data are discussed in terms of the involvement of caveolae in receptor localisation, Ca(2+) entry pathways and SR Ca(2+) release, and the role of these in agonist signalling.
Affiliation: University of Liverpool, Merseyside, UK. firstname.lastname@example.orgShow MeSH
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Mentions: The effect of MCD was also evaluated in electrophysiological studies on freshly isolated coronary artery myocytes. When Cs+ was used in the pipette solution (instead of K+), no outward current was apparent. A small inward current (2.1 ± 0.1 pA/pF) was observed, peaking at 0 mV and sensitive to inhibition with nifedipine and potentiation with Bay K8644 (n = 4, data not shown). Experiments evaluating the effect of cholesterol extraction were carried out in the presence of 1 μM Bay K8644. Treatment with MCD for 10 min did not significantly alter the inward current over the entire voltage range tested, as shown in Fig. 6A (peak current at 0 mV: control 2.66 ± 0.8 pA/pF versus 2.65 ± 0.4 pA/pF, n = 3).
Affiliation: University of Liverpool, Merseyside, UK. email@example.com