High carbohydrate high fat diet causes arterial hypertension and histological changes in the aortic wall in aged rats: The involvement of connective tissue growth factors and fibronectin.

Abstract

Age and diabetes are risk factors for arterial hypertension. However, the relationship between age, connective tissue growth factors, vascular aging and arterial hypertension while on a the high-carbohydrate high-fat diet (HCHFD) remains poorly understood. To estimate the relationship between humoral factors, the morphological changes of aorta and impaired blood pressure regulation under the influence of age and a HCHFD. A study was carried out in male Wistar rats, which were divided into the following groups: 1st (n=15) - naive young rats; 2nd (n=15) - young rats, exposed to HCHFD; 3rd (n=14) - naive old rats; 4th (n=12) - old rats exposed to HCHFD. The age of old rats was 540days, and young rats 150days at the end of the diet. HCHFD contained proteins 16%, fats 21%, carbohydrates 46%, including 17% fructose, 0.125% cholesterol, 90days. Blood pressure and body weight were measured weekly, carbohydrate metabolism, histological signs of changes in the aorta, serum transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), fibronectin, and endothelin-1 levels were determined one week after the onset of diet. The severity of arterial hypertension and its histological signs in the aortic wall was found to be most pronounced in elderly rats kept on a HCHFD. In young rats kept on a HCHFD, arterial hypertension was transient. An increase in systolic blood pressure has a positive correlation with the degree of obesity, serum fibronectin, and endothelin-1 content, and impaired carbohydrate metabolism. The rise in diastolic blood pressure has a positive correlation with the serum CTGF, endothelin-1, fibronectin levels and aortic wall thickness, and impaired carbohydrate metabolism. A rise in the serum concentration of fibronectin was also associated with increased endothelin-1, TGFβ and CTGF serum levels. This study indicated that an increase in blood pressure in old rats with a high-carbohydrate high-fat diet is due to a disturbance of a structure of the vascular wall, the release of fibronectin, which can occur under the influence of carbohydrate metabolism disorders, endothelin-1, TGFβ and CTGF.