title: Ascorbic acid levels and neutrophil superoxide production in blood of pre-, early and late hypertensive stroke-prone spontaneously hypertensive rats.
abstract: We compared ascorbic acid (AA) levels in the blood and TPA- and fMLP-stimulated superoxide (O(2)(•-)) production in neutrophils of pre-, early, and late hypertensive stroke-prone spontaneously hypertensive rats (SHRSP) with those of age-matched Wistar Kyoto rats (WKY), or two other normotensive strains of rats. Plasma and lymphocyte AA levels were about two-fold higher in SHRSP as early as 4 weeks old compared to WKY, and also higher than those of Wistar and Sprague-Dawley (SD) rats. Levels of AA were high in the liver and adrenal glands of SHRSP, indicating congenitally high AA levels. The production of O(2)(•-) in neutrophils was about two-fold higher in SHRSP than in WKY even at 4 weeks of age, and increased with age in both strains. Among SHRSP, AA levels in lymphocytes decreased at the late hypertensive stages with a decrease in hepatic l-gulono-γ-lactone oxidase (GLO) activities. These data suggest that bi-phasic AA levels in the blood of SHRSP comprise congenitally high levels and a decrease after persistent hypertension due to enhanced O(2)(•-) production and a decrease in de novo AA synthesis through GLO.
authors.affiliation: National Institute of Health and Nutrition, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Sato
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikeda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ito
authors.forename: Takako
authors.initials: T
authors.lastname: Tomita
authors.forename: Kaori
authors.initials: K
authors.lastname: Yokotani
authors.forename: Masatsune
authors.initials: M
authors.lastname: Murata
authors.forename: Keizo
authors.initials: K
authors.lastname: Umegaki
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000375:Aging / Q000097:blood*; D000818:Animals; D001205:Ascorbic Acid / Q000097:blood*; D004195:Disease Models, Animal; D005947:Glucose / Q000378:metabolism; D006973:Hypertension / Q000097:blood*; D050544:L-Gulonolactone Oxidase / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D013481:Superoxides / Q000378:metabolism*
chemical_list: D013481:Superoxides; D050544:L-Gulonolactone Oxidase; D005947:Glucose; D001205:Ascorbic Acid