Figure 5.

Reduced mortality and decreased MAPK activation with propanolol. (A) Cardiac cellular lysates from 16-wk-old mice were collected and analyzed for MAPK pathway activity (indicated by JNK expression and phosphorylation of p38 Map kinase), and versus a control (GAPDH). MAPK pathway is overactive in PLN-R9C mice. (B) Treating mice with propanolol reduces activity of MAPK pathway at 16 wk in PLN-R9C mice compared to wild type. (C) Sixteen-wk-old mice were subjected to M-mode echocardiography and left ventricular end diastolic dimension (LVEDD), left ventricular end systolic dimension (LVESD) and fractional shortening (FS) were assessed. Propanolol treatment reduces LVEDD, LVESD and fractional shortening to wild type levels. (D) WT and PLN-R9C mice were treated with/without propanolol (0.5 g/L in drinking water) starting at 8 wk of age. Mortality was monitored in all groups at 16 wk. Cardiac lysates and tissues were obtained and analyzed as previously described ⁷. Antibodies used: phospho-p38 – BD ♯612281 from BD bioscience and SAPK/JNK – mAb ♯9258 from Cell Signaling.