Mesenteric and hepatic vascular reactivity in Donryu rats with and without a cholesterol-supplemented diet.
Vascular function of Donryu rats fed on a normal or cholesterol-supplemented diet was examined in the isolated perfused mesenteric arterial bed and portally perfused liver. In mesenteric preparations, frequency-dependent vasoconstriction to electrical field stimulation (4-32 Hz, 1 ms, 90 V, 30 s) and dose-dependent vasoconstriction to noradrenaline (0.15-1500 nmol) was similar in both groups. Dose-dependent vasoconstriction to alpha, beta-methylene ATP (0.05-500 nmol) via P2x purinoceptors was significantly impaired in Donryu rats fed on a cholesterol-supplemented diet. In preparations with raised tone (methoxamine 5-35 microM), there was no significant difference in endothelium-dependent relaxation to acetylcholine and ATP, or endothelium-independent relaxation to sodium nitroprusside. In liver preparations, there was no difference in frequency-dependent vasoconstriction to electrical field stimulation (2-32 Hz, 1 ms, 90 V, 30 s), or dose-dependent vasoconstriction to noradrenaline (0.05-500 nmol) and alpha, beta-methylene ATP (0.05-500 nmol) between the groups. In conclusion, in mesenteric arteries, but not in the hepatic portal vasculature of Donryu rats fed on cholesterol P2x purinoceptor function is impaired, but sympathetic neurotransmission is unaffected. Mesenteric endothelial and smooth muscle function is unimpaired.
Ralevic
V
V
Department of Anatomy and Developmental Biology, University College London, UK.
Aliev
G
G
Burnstock
G
G
D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D004558:Electric Stimulation; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology*; D009126:Muscle Relaxation / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011168:Portal System / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D002791:Cholesterol, Dietary; D014665:Vasodilator Agents; D009599:Nitroprusside; D000255:Adenosine Triphosphate; D000109:Acetylcholine; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine