Increased Expression of Peroxisome Proliferator-Activated Receptor-α and -γ in Blood Vessels of Spontaneously Hypertensive Rats

ABSTRACT—Peroxisome proliferator-activated receptors (PPARs) are a family of ligand-activated transcription factors that include PPAR-α, PPAR-γ, and PPAR-δ. We hypothesized that PPAR expression in blood vessels could be reduced in hypertension to result in increased vascular growth and reduced apoptosis. We investigated the abundance of PPAR-α and PPAR-γ in aorta and mesenteric arteries from young (6-week-old) and adult (16-week-old) spontaneously hypertensive rats (SHR) compared with age-matched control Wistar-Kyoto rats (WKY). mRNA levels of PPAR-α and PPAR-γ were determined by reverse transcription-polymerase chain reaction. Protein expression was evaluated by Western blot and by immunohistochemistry. PPAR-γ was expressed in aortic and mesenteric vascular smooth muscle cells (VSMCs) from intact tissue and cultured cells. PPAR-α was expressed in intact vascular tissue but was almost undetectable in cultured VSMCs. In mesenteric arteries from adult SHR, PPAR-α and PPAR-γ mRNA levels were significantly greater than in WKY (P