MYOCARDIAL COLLAGEN CHANGES AND EDEMA IN RATS WITH HYPERDYNAMIC SEPSIS

Objective: To determine if sepsis, which is accompanied by both systol ic and diastolic myocardial dysfunction, involves changes in myocardia l collagen, as myocardial collagen changes can affect both myocardial compliance and contractility. Design: Prospective, randomized, control led study. Setting: Animal laboratory at a university-affiliate hospit al. Subjects: Male Sprague-Dawley rats, weighing 310 to 396 g. Interve ntions: Cecal ligation and perforation (to induce sepsis) for 24 (n = 9) or 48 hrs (n = 9); sham laparotomy for 24 (n = 10) or 48 hrs (n = 9 ) with saline fluid resuscitation or normal control (n = 5) groups. Me asurements and Main Results: Collagen content and interstitial space w ere determined, using polarized light microscopy and a computer video densitometry system. At 24 and 48 hrs post surgery, heart rate and car diac index were increased, and systemic vascular resistance index was decreased significantly in the sepsis vs. the sham rats, Collagen cont ent was decreased significantly in the sepsis vs, the sham groups both at 24 and 48 hrs following surgery (1.83 +/- 0.79 [SD] % [24 hrs], 1. 76 +/- 0.31% [48 hrs] vs. 2.83 +/- 0.73% [24 hrs], 2.25 +/- 0.72% [48 hrs]; p < .01), Interstitial space was increased significantly in the sepsis vs, the sham groups (13.9 +/- 3.5% [24 hrs], 15.6 +/- 5.2% [48 hrs] vs, 8.6 +/- 4.2% [24 hrs], 9.9 +/- 4.8% [48 hrs]; p < .01). Concl usions: Sepsis is accompanied by changes in myocardial collagen conten t and myocardial edema, These changes may contribute to the systolic a nd diastolic myocardial dysfunction, and particularly to the ventricul ar dilation, observed in sepsis.