title: Conjugated linoleic acid improves blood pressure by increasing adiponectin and endothelial nitric oxide synthase activity.
abstract: Conjugated linoleic acid (CLA) has been reported to reduce blood pressure in obese insulin-resistant rats, but its mechanism of action has not been identified. The objective of this study was to determine whether CLA isomers can reduce obesity-related hypertension in the fa/fa Zucker rat in relation to adiponectin production and endothelial nitric oxide synthase (eNOS) activation. Obese fa/fa Zucker rats were randomly assigned to one of four groups: (1) cis-9,trans-11-CLA, (2) trans-10,cis-12 (t10,c12)-CLA, (3) control or (4) captopril. After 8 weeks, systolic blood pressure increased 30% in control obese rats. This increase was attenuated 11%-13% in the t10,c12-CLA isomer and captopril groups, respectively. The t10,c12-CLA isomer concurrently elevated adiponectin levels in both plasma and adipose tissue and increased phosphorylated eNOS in adipose tissue as well as the aorta. Although a direct effect of CLA was not observed in cultured endothelial cells, direct adiponectin treatment increased phosphorylation of eNOS. Endothelial nitric oxide synthase phosphorylation was also increased in adipose of fa/fa Zucker rats infused with adiponectin in parallel with improvements in blood pressure. Our results suggest that the t10,c12-CLA isomer attenuates development of obesity-related hypertension, at least in part, by stimulating adiponectin production, which subsequently activates vascular eNOS.
authors.affiliation: Department of Human Nutritional Sciences, University of Manitoba, Canada.
authors.forename: Vanessa
authors.initials: V
authors.lastname: DeClercq
authors.forename: Carla G
authors.initials: CG
authors.lastname: Taylor
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Wigle
authors.forename: Brenda
authors.initials: B
authors.lastname: Wright
authors.forename: Leslee
authors.initials: L
authors.lastname: Tworek
authors.forename: Peter
authors.initials: P
authors.lastname: Zahradka
mesh_terms: D052242:Adiponectin / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D008297:Male; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D051381:Rats; D011924:Rats, Zucker
chemical_list: D052242:Adiponectin; D044243:Linoleic Acids, Conjugated; D052250:Nitric Oxide Synthase Type III