Figure 3.

AMPKα1 is involved in multiple Ca²⁺ signaling mechanisms. A) AMPKα1 is activated by thapsigargin (Tg). B) AMPKα1 response to thapsigargin is dependent on Ca²⁺ influx (n=3). Con, vehicle control; (+), 1.8 mM [Ca²⁺]_o; (−), 10 μM [Ca²⁺]_o. C) AMPKα1 inhibition using compound C (Cmpd C, 50 μM, 2.25-h pretreatment) or shRNA (Δα1) attenuates thapsigargin-induced Ca²⁺ entry (ratio), assayed using Fura-2AM. Tx, time thapsigargin or vehicle control added to culture medium (n>5, tracings represent mean for each group, error bars not shown). D) Peak thapsigargin-induced Ca²⁺ entry is reduced by 50% in the presence of AMPKα1 inhibition (Δα1, AMPKα1 shRNA-expressing PMVECs) (n>5). Values are means ± se. *P < 0.05.