Ms 550d 40 mhz frequency probe

Global PDE1C knockout (PDE1C-KO) mice were backcrossed to C57BL/6J mice for more than 10 generations. For experiments with genetically modified mice, age/sex/genetic background matched mice were randomly separated into indicated groups based on animal identification number. For the Ang II infusion model, PDE1C-KO and wild type (PDE1C-WT) mice from sibling mating at 10–12 weeks of age were subjected to subcutaneous infusion with vehicle saline or Ang II (1.4 mg/kg/day) for 28 days as described previously.^{16 (link)} For the doxorubicin cardiac toxicity model, PDE1C-WT, PDE1C-KO, or C57BL/6J male or female mice aged 10–12 weeks were randomly separated into indicated groups. Doxorubicin (20 mg/kg in saline) was administered via intra-peritoneal injection (i.p.) in a single bolus. IC86340 (6 mg/kg/day) and/or ZM241385 (10 mg/kg/day) in 20% DMSO/buffered saline were injected via i.p. two days prior to doxorubicin treatment and continued for additional five days. Mouse cardiac function was measured by echocardiography before sacrifice. Echocardiography was monitored in anesthetized mice using a Vevo2100 echocardiography machine equipped with an MS-550D 40 MHz frequency probe (VisualSonics, Toronto, Canada) as described previously in a blinded manner.^{15 (link)}