Effects of acute hypercholesterolemia on blood pressure and pressor response to norepinephrine in rats

• Published in: Blood pressure 2004, Vol.13 (1), p.56-61
• Main Authors: Atarashi, Keiichiro, Ishiyama, Akihiro, Minami, Mayumi, Takagi, Masao, Omata, Masao
• Format: Article
• Language: English
• Subjects: Acute Disease; Animals; blood exchange; Blood Pressure - drug effects; Cholesterol, Dietary - toxicity; Exchange Transfusion, Whole Blood; Hypercholesterolemia - physiopathology; hypercholesterolemia-induced hypertension; Hypertension - chemically induced; Lipid Peroxidation; Lipids - blood; Male; Malondialdehyde - blood; norepinephrine; Norepinephrine - pharmacology; Oxidation-Reduction; oxygen free radicals; Proteinuria - etiology; Rats; Rats, Sprague-Dawley
• ISSN: 0803-7051; 1651-1999
• DOI: 10.1080/08037050310028471

To examine if high cholesterol in blood acutely affects the blood pressure, we partly exchanged the blood of normal rats for that of hypercholesterolemic rats. Male Sprague-Dawley rats were fed for 8 weeks with a high-cholesterol diet (4% cholesterol; HC) or a normal diet (NC). The rats were catheterized, and blood of animals in NC was partly exchanged with that of HC (N-H) or other animals in NC (N-N). Systolic blood pressure (SBP) and the pressor response to norepinephrine (NE) in N-H were compared with those of N-N. Serum lipids and malondialdehyde (MDA), and urinary excretion of protein (UP) and NE (UNE) were determined. After 8 weeks, SBP, serum total cholesterol (TC), MDA, UP and UNE were higher in the HC. Blood exchange caused an increase in TC, MDA and SBP in only the N-H. Increases in SBP caused by NE injection were rather less in the N-H than in the N-N. The blood pressure increase induced by a high-cholesterol diet seemed to be caused by certain factors in the blood of hypercholesterolemic rats. Excessive lipid oxidation induced by hypercholesterolemia may be involved in the blood pressure elevation.