title: Synergistic effects of high blood cholesterol and hypertension on leukocyte and platelet recruitment in the cerebral microcirculation.
abstract: Hypertension or hypercholesterolemia can induce a proinflammatory and prothrombogenic phenotype in the microcirculation of the brain; however, less is known about how the combination of these risk factors affects the vasculature. We recently reported that a moderate (60%) increase in plasma cholesterol blunts the recruitment of leukocytes and platelets in the cerebral microvessels elicited by hypertension. In this study, we examined whether larger increments in blood cholesterol (4-fold) exerts a similar modulating influence on the vasculature in the presence of hypertension. Apolipoprotein E-knockout mice with deoxycorticosterone acetate salt-induced hypertension were placed on a high-cholesterol diet and exhibited exaggerated leukocyte and platelet adhesion responses in cerebral microvessels. Intermittent feeding (every fourth day) with high-cholesterol diet yielded similar phenotypic changes in the vasculature. Once the mice were placed on high-cholesterol diet, 4 days on normal diet (ND) were needed to revert to a normal vascular phenotype. Angiotensin II type 1 receptors and reactive oxygen species seem to contribute to the vascular responses induced by hypercholesterolemia and hypertension. Our findings indicate that the combination of hypertension and large increases in plasma cholesterol concentration results in a severe, but reversible, inflammatory and thrombogenic phenotype in the cerebral microvasculature.
authors.affiliation: Department of Molecular and Cellular Physiology, LSU Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932. dgrang@lsuhsc.edu.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Rodrigues
authors.forename: Lidiana D
authors.initials: LD
authors.lastname: Almeida-Paula
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Granger
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D001792:Blood Platelets / Q000473:pathology* / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002791:Cholesterol, Dietary / Q000009:adverse effects; D015897:Comorbidity; D064791:Desoxycorticosterone Acetate / Q000009:adverse effects; D004195:Disease Models, Animal; D006937:Hypercholesterolemia / Q000150:complications* / Q000453:epidemiology* / Q000209:etiology; D006973:Hypertension / Q000139:chemically induced / Q000150:complications* / Q000453:epidemiology*; D007962:Leukocytes / Q000473:pathology* / Q000502:physiology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000502:physiology
chemical_list: D001057:Apolipoproteins E; D002791:Cholesterol, Dietary; D017382:Reactive Oxygen Species; D044140:Receptor, Angiotensin, Type 1; D064791:Desoxycorticosterone Acetate
keywords: hypercholesterolemia; hypertension; inflammation