title: Differences in inositol phosphate production in blood vessels of normotensive and spontaneously hypertensive rats.
abstract: 1. Total inositol phosphate formation was measured in labelled femoral and iliac arteries and veins of 14 week-old spontaneously hypertensive rats (SHR) and age-matched Wistar Kyoto (WKY) controls, either unstimulated or in the presence of noradrenaline. 2. Basal levels of [3H]-inositol phosphates and [3H]-phosphatidylinositol were significantly enhanced in SHR femoral artery, but not in the other 3 vessels, compared with WKY. 3. Noradrenaline stimulated phosphoinositide hydrolysis in all four vessels of SHR and WKY. Pretreatment with prazosin (10(-7)-10(-6) M) but not with yohimbine (10(-7) M), inhibited the noradrenaline-induced inositol phosphate formation indicating an alpha 1-adrenoceptor-mediated response. 4. In the femoral artery of SHR compared to WKY, [3H]-inositol phosphate accumulation induced by noradrenaline (10(-7)-10(-5) M) was significantly reduced when expressed relative to basal values although the response to higher concentrations (10(-4)-10(-3) M) was not altered. In contrast, a significant reduction of inositol phosphates was seen only with 10(-7) M noradrenaline when absolute values were compared. In the other three vessels, no difference in noradrenaline-induced [3H]-inositol phosphate formation was observed between strains. 5. These data suggest that phosphoinositide hydrolysis-mediated by alpha 1-adrenoceptors may be reduced in some but not all blood vessels of adult SHR.
authors.affiliation: University Department of Medicine and Therapeutics, Gardiner Institute, Western Infirmary, Glasgow.
authors.forename: E
authors.initials: E
authors.lastname: Vila
authors.forename: I M
authors.initials: IM
authors.lastname: Macrae
authors.forename: J L
authors.initials: JL
authors.lastname: Reid
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000378:metabolism*; D006868:Hydrolysis; D006973:Hypertension / Q000378:metabolism*; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000096:biosynthesis*; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012016:Reference Values; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D007295:Inositol Phosphates; D015016:Yohimbine; D009638:Norepinephrine; D011224:Prazosin