title: Chronic ingestion of H1-antihistamines increase progression of atherosclerosis in apolipoprotein E-/- mice.
abstract: Although increased serum histamine levels and H1R expression in the plaque are seen in atherosclerosis, it is not known whether H1R activation is a causative factor in the development of the disease, or is a host defense response to atherogenic signals. In order to elucidate how pharmacological inhibition of histamine receptor 1 (H1R) signaling affects atherogenesis, we administered either cetirizine (1 and 4 mg/kg. b.w) or fexofenadine (10 and 40 mg/kg. b.w) to ApoE-/- mice maintained on a high fat diet for three months. Mice ingesting a low dose of cetirizine or fexofenadine had significantly higher plaque coverage in the aorta and cross-sectional lesion area at the aortic root. Surprisingly, the higher doses of cetirizine or fexofenadine did not enhance atherosclerotic lesion coverage over the controls. The low dose of fexofenadine, but not cetirizine, increased serum LDL cholesterol. Interestingly, the expression of iNOS and eNOS mRNA was increased in aortas of mice on high doses of cetirizine or fexofenadine. This may be a compensatory nitric oxide (NO)-mediated vasodilatory mechanism that accounts for the lack of increase in the progression of atherosclerosis. Although the administration of cetirizine did not alter blood pressure between the groups, there was a positive correlation between blood pressure and lesion/media ratio at the aortic root in mice receiving the low dose of cetirizine. However, this association was not observed in mice treated with the high dose of cetirizine or either doses of fexofenadine. The macrophages or T lymphocytes densities were not altered by low doses of H1-antihistamines, whereas, high doses decreased the number of macrophages but not T lymphocytes. The number of mast cells was decreased only in mice treated with low dose of fexofenadine. These results demonstrate that chronic ingestion of low therapeutic doses of cetirizine or fexofenadine enhance progression of atherosclerosis.
authors.affiliation: Division of Allergy, Clinical Immunology & Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Vineesh V
authors.initials: VV
authors.lastname: Raveendran
authors.affiliation: Division of Allergy, Clinical Immunology & Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Donald D
authors.initials: DD
authors.lastname: Smith
authors.affiliation: Division of Allergy, Clinical Immunology & Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Tan
authors.affiliation: Division of Allergy, Clinical Immunology & Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Sweeney
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Reed
authors.affiliation: Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Colleen A
authors.initials: CA
authors.lastname: Flynn
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Ossama W
authors.initials: OW
authors.lastname: Tawfik
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee, United States of America.
authors.forename: Ginger
authors.initials: G
authors.lastname: Milne
authors.affiliation: Division of Allergy, Clinical Immunology & Rheumatology, Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
authors.forename: Kottarappat N
authors.initials: KN
authors.lastname: Dileepan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D050197:Atherosclerosis / Q000139:chemically induced* / Q000235:genetics / Q000473:pathology*; D001774:Blood Chemical Analysis; D018955:CD36 Antigens / Q000378:metabolism; D017332:Cetirizine / Q000009:adverse effects* / Q000097:blood / Q000494:pharmacology; D008078:Cholesterol, LDL / Q000097:blood; D059305:Diet, High-Fat; D018450:Disease Progression; D005455:Fluorescent Antibody Technique; D006634:Histamine H1 Antagonists / Q000009:adverse effects* / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D019001:Nitric Oxide Synthase / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D016593:Terfenadine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology
chemical_list: D001057:Apolipoproteins E; D018955:CD36 Antigens; D008078:Cholesterol, LDL; D006634:Histamine H1 Antagonists; D016593:Terfenadine; C093230:fexofenadine; D019001:Nitric Oxide Synthase; D017332:Cetirizine