Noradrenaline and angiotensin II modify vascular prostanoid release in fructose-fed hypertensive rats.
1 A fructose-enriched diet induces hypertension, metabolic alterations and insulin resistance in rats, resembling human metabolic syndrome. Previously, we found that prostanoid production was altered in fructose-fed rats. 2 This study analysed the effects of incubation with noradrenaline (NA) and angiotensin II (Ang II) on prostanoid release in mesenteric vascular beds from control and fructose-fed rats. Animals which received fructose solution (10% w/v) for 22 weeks showed higher systolic blood pressure and triglyceridaemia. 3 In controls, NA increased 6-keto-prostaglandin (PG) F(1)alpha (prostacyclin metabolite) and thromboxane (TX) production. Ang II increased only TX release. In fructose-fed animals, NA increased 6-keto-PG F(1)alpha and TX. PGF(2)alpha (vasoconstrictor) was also elevated. Ang II also increased PGF(2)alpha and PGE(2) levels. 4 In conclusion, in fructose rats Ang II in vitro stimulates a vasoconstrictor prostanoid not stimulated in controls. This could be related to the observed in vivo blood pressure increase. In fructose-fed animals, NA and Ang II also augment vasodilator prostanoids, suggesting a compensatory mechanism because of long-term hypertension.
Puyó
A M
AM
Cátedras de Anatomía Humana (macro y microscópica), Instituto de Morfología J.J. Naón, Unidad de Neurosciencias; and 1a Cátedra de Anatomía, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Mayer
M A
MA
Giorgi
S
S
Gómez
A H
AH
Peredo
H A
HA
D000804:Angiotensin II / Q000502:physiology*; D000818:Animals; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D005632:Fructose / Q000008:administration & dosage* / Q000633:toxicity; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D008643:Mesentery / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000502:physiology*; D011453:Prostaglandins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D011453:Prostaglandins; D000804:Angiotensin II; D005632:Fructose; D009638:Norepinephrine