Impact of a High-fat Diet on the Development of Chronic Inflammation in Heart of Wistar rats.

Abstract

Obesity is linked to the development of low-grade, chronic inflammation. Obesity-related inflammation appears to be a different type of inflammation, mainly due to excessive food intake and unusual homeostasis. It can be evaluated by measuring the concentration of pro- and anti-inflammatory marker molecules – C-reactive protein (CRP), serum amyloid-A (SAA) and interleukin-4. The aim of the present study is to evaluate the rate of the inflammatory process in heart, provoked by the consumption of a high-fat diet. Sixty 8-week-old male Wistar rats were used in this experiment. The laboratory animals were fed orally with two different types of rodent food for 14 or 18 weeks – a high-fat diet (experimental groups) and standard rodent food (control groups). They all were kept under standard housing conditions. The levels of the pro- and anti-inflammatory markers in tissue homogenates from heart were analyzed using ELISA. Their expression in tissue samples was detected immunohistochemically by the biotin-streptavidin-peroxidase method. The total protein concentration was determined by the Lawry method. CRP levels showed no significant differences when the control group was compared with the groups fed with a high-fat diet (p>0.05). The SAA levels detected were also insignificantly changed. Only the IL-4 tissue levels showed tendency to increase (p<0.05) in the high-fat diet group. Our experiment indicates that there is a specific reaction of the heart to a high-fat diet. It also refers to the existence of adaptive mechanisms allowing the heart to counteract the development of dietary induced inflammation.