Hemodynamics and aortic tension induced by two septic shock models in rats

Abstract

To compare the ventricular-dynamic parameters and thoracic aorta tension induced by two septic shock models in rats. Septic shock models were induced by cecal ligation or puncture (CLP) and intraperitoneal injection of lipopolysaccharide (LPS) in rats. The carotid artery was cannulated and connected to a pressure transducer to determine mean arterial blood pressure (MABP). Ventricular dynamic parameters, including heart rate (HR), left ventricular developed pressure (LVDP) and maximal rise/fall velocity of ventricular pressure (± dP/dtmax) were determined. Isolated thoracic rings were mounted on an organ bath and the tension of the vessel was recorded. The mortality was 65.2% in CLP shock rats, but no death in LPS shock rats. The MABP and HR of CLP rats were decreased more prominently than those of LPS rats (P < 0.01). Contraction induced by high K(+) (60 mmol/L) or 10⁻⁶ mol/L phenylephrine (PE) in endothelium-intact and endothelium-denuded aortic rings was all attenuated, but in LPS rats it was more prominent (P < 0.01). Two rat septic shock models can decrease ventricular-dynamic parameters and vasoconstriction responsiveness of aorta. The ventricular-dynamic parameters decrease more prominently in CLP model, while vasoconstriction responsiveness of aorta changes more in LPS model.