title: Peroxisome proliferator-activated receptor gamma regulates angiotensin II-stimulated phosphatidylinositol 3-kinase and mitogen-activated protein kinase in blood vessels in vivo.
abstract: Angiotensin (Ang) II is implicated in hypertension, vascular remodeling, and insulin resistance. Peroxisome proliferator-activated receptor (PPAR) gamma activators increase insulin sensitivity and improve Ang II-induced vascular remodeling. We evaluated the effects of the PPAR-gamma activator rosiglitazone on Ang II signaling in aorta and mesenteric arteries. Rats received Ang II by subcutaneous infusion and/or rosiglitazone per os for 7 days. Blood pressure rise in Ang II-infused rats was attenuated by rosiglitazone. Ang II significantly increased Ang II type 1 receptor expression in the mesenteric arteries (P<0.001), whereas that of the aorta was decreased (P<0.05), changes which were reversed by rosiglitazone. Akt activity was increased by Ang II and returned to basal levels under rosiglitazone in both vascular beds. However, Ang II-induced extracellular signal-regulated kinase 1/2 activity increased in aorta but not in mesenteric vessels (P<0.001), where 4E-binding protein 1 activity was significantly increased by Ang II and inhibited by PPAR-gamma activation. In response to Ang II, Src homology (SH) 2-containing inositol phosphatase 2 activity was increased (P<0.05) in both vascular beds. In conclusion, PPAR-gamma activator rosiglitazone attenuated Ang II-induced blood pressure elevation and intracellular signaling on aorta and mesenteric vessels. There was differential inhibition of Ang II type 1 receptor receptors/phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase 1/2 in both vessels. Effects of PPAR-gamma activators on these pathways could contribute to regression of vascular remodeling in models of hypertension and diabetes and, accordingly, in hypertensive diabetic patients.
authors.affiliation: Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, Montreal, Quebec, Canada.
authors.forename: Karim
authors.initials: K
authors.lastname: Benkirane
authors.forename: Emilie C
authors.initials: EC
authors.lastname: Viel
authors.forename: Farhad
authors.initials: F
authors.lastname: Amiri
authors.forename: Ernesto L
authors.initials: EL
authors.lastname: Schiffrin
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000201:enzymology* / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D008297:Male; D008638:Mesenteric Arteries / Q000201:enzymology* / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D047495:PPAR gamma / Q000378:metabolism / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism; D000077154:Rosiglitazone; D015398:Signal Transduction / Q000187:drug effects; D045162:Thiazolidinediones / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D047495:PPAR gamma; D044140:Receptor, Angiotensin, Type 1; D045162:Thiazolidinediones; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000077154:Rosiglitazone; D000804:Angiotensin II; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases