Figure 2. SR Ca regulatory proteins in Hsp20 TG hearts.
(A) Representative blots of SR Ca-cycling proteins in WT and Hsp20 TG hearts. (B) Quantitative results revealed that SERCA2a, phospholamban pentamer (PLNp), phospholamban monomer (PLNm), total PLN, ryanodine receptor (RYR2), calsequestrin (CSQ), sodium/calcium exchanger (NCX) and L-type Ca channel (LTCC) levels were not altered. (n=6 for each protein). (C) Typical L-type Ca currents in WT and TG cardiomyocytes elicited by a series of depolarizing steps from a holding potential of −50 mV. (D) Average peak current density-voltage relationships of L-type Ca currents recorded in WT (n=15) and TG (n=12) cardiomyocytes. (E) Ramp voltage protocol (top panel) is used to elicit membrane currents (middle panel) in absence and presence of 5mM NiCl2, and the subtraction of the 2 traces gives the Ni2+-sensitive NCX current (bottom panel). (F) Average current density-voltage relationships of NCX currents recorded in WT (n=10) and TG (n=11) ventricular myocytes.