The Effect And Pathophysiological Mechanism Of High Free Fatty Acids (FFAs) On The Cardiac Structure And Function

Objective Obesity is often associated with cardiac hypertrophy and abnormal cardiac function, the mechanism of which is still not quite clear. The aims of the present study were to explore the pathophysiological links between elevated circulating FFAs concentration and the cardiac structure and function in obese insulin resistance rat model. Materials and methods Male S-D rats, 4 weeks in age, were fed with high-fat diet (OB) or standard laboratory chow(NC) respectively for 8,16 and 24 weeks. Whole-body insulin sensitivity was assessed by a hyperinsulinemic- euglycemic clamp. The maximum velocity of myocardial contraction (+dP/dt max) and the maximum velocity of myocardial diastole (-dP/dt max) of intracardiac pressure were measured by physiological polygraph to evaluate cardiac function. The concentrations of triglyceride (TG), FFAs and angiotensin II(Ang II) both in blood and in left ventricular portions of heart were measured. The ultrastructures of myocardiac cells were observed by electron microscope, and myocardiac cell diameter(MCD) were examined to evaluate the degree of cardiac hypertrophy. The expressions of NF-κB,IκB and iNOS in myocardium were analyzed by the methods of immunohistochemistry.