Figure 3.

Antisense ONs inhibit the ability of IGF-1 to increase T-type calcium current. (A) Representative T-type calcium current traces from cultured atrial myocytes. Records are the difference traces obtained by subtracting currents elicited at a test potential of −30 mV from holding potentials of −90 and −50 mV in the presence of 5 mM calcium in the recording solution. Each trace represents the average of three to four individual current records recorded from different cells under each condition: serum-free medium (basal), medium containing 52 nM IGF-1, and medium containing 52 nM IGF-1 plus 1 μM of the antisense ON atrium 1 or β-binding. (B) T-current density/voltage relationships for cells cultured in the presence of IGF-1 (52 nM, circles), IGF-1 plus antisense (crosses) or sense (triangles) ON, and in serum-free medium (squares). Labels above each graph indicate the ON tested. Number of determinations at each voltage varied from 3 to 9.