Figure 2

In vitro diaphragmatic proteolysis. (a) Controlled mechanical ventilation (CMV) increased total diaphragmatic proteolysis after 18 hours, but not after 6 hours, of mechanical ventilation versus control (CON) and pressure support ventilation (PSV). Units in (a) are nanomoles of tyrosine per milligram of protein per hour. Both chymotrypsin-like activity (b) and tripeptidylpeptidase II activity (c) were increased by 18 hours of CMV. Units in (b) and (c) are relative fluorescence units (RFU) per microgram per minute. Values are mean ± standard error. *P < 0.05 compared with CON group. ^†P < 0.05 compared with PSV group at 6 and 18 hours. ^‡P < 0.05 compared with CMV group at 6 hours.