Cardiomyocyte sarcomere shortening depression and subsequent up-regulation after challenge with 4 μg/g of lipopolysaccharide (LPS). (A) Typical experimental recordings of sarcomere shortening and Ca_i transients in cardiomyocytes isolated at baseline and at different times (as shown) after challenge with 4 μg/g of LPS. (B–E) Average sarcomere shortening (B), sarcomere departure velocity (ΔSS/dt; C), return velocity (D), sarcomere time to peak (E), and diastolic sarcomere length (F) at baseline, 12 h after LPS administration, at day 3, and at day 6. Data are shown as mean ± SD. N = 37 cells from seven mice at baseline (37/7), 17/2 for 12 h, 39/3 for day 3, and 14/2 for day 6. BL = baseline; r.u. = ratiometric units. *P < 0.05 versus baseline.