Fig. 4.
Phospholamban is down-regulated at day 3. Sarcoplasmic reticulum Ca2+ pump (SERCA; A) and phospholamban (PLB; B) expression in mice at baseline, 12 h after lipopolysaccharide (LPS) administration, and at day 3. Upper panels show illustrative Western blots of SERCA, phospholamban, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in left ventricle extracts. Lower panels shown average data, normalized to GAPDH (loading control), and shown as a ratio of baseline. N = 6 hearts each. Phospholamban was visualized in the pentameric (25 kilodalton [kd]) and tetrameric forms (20 kd). Average data shown are for the predominant 20-kd isoform, and similar results were obtained for the 25-kd isoform. Data are shown as mean ± SD. BL = baseline. *P < 0.05 versus baseline.