effect of high-fructose intake on the vasopressor response to angiotensin ii and adrenergic agonists in Sprague-Dawley rats

ABSTRACT

Effect of losartan was assessed on systemic haemodynamic responses to angiotensin II [Ang II] and adrenergic agonists in the model of high-fructose-fed rat. Twenty-four Sprague-Dawley [SD] rats were fed for 8 weeks either 20% fructose solution [FFR] or tap water [C] ad libitum. FFR or C group received losartan [10mg/kg/day p.o.] for 1 week at the end of feeding period [FFR-L and L] respectively, then the vasopressor responses to Ang II, noradrenaline [NA], phenylephrine [PE] and methoxamine [ME] were determined. The responses [%] to NA, PE, ME and Ang II in FFR were lower [p<0.05] than C [FFR vs. C; 22 +/- 2 vs. 32 +/- 2, 30 +/- 3 vs. 40 +/- 3, 9 +/- 1 vs. 13 +/- 1, 10 +/- 1 vs. 17 +/- 1] respectively. L group had blunted [p<0.05] responses to NA, PE, ME and Ang II compared to C [L vs. C; 26 +/- 2 vs. 32 +/- 2, 30 +/- 3 vs. 40 +/- 3, 7 +/- 0.7 vs. 13 +/- 1, 5 +/- 0.4 vs. 17 +/- 1] respectively. FFR-L group had aggravated [p<0.05] response to NA and ME, but blunted response to Ang II compared to FFR [FFR-L vs. FFR; 39 +/- 3 vs. 22 +/- 2, 11 +/- 1 vs. 9 +/- 1, 3 +/- 0.4 vs. 10 +/- 1] respectively. Fructose intake for 8 weeks results in smaller vasopressor response to adrenergic agonists and Ang II. Data also demonstrated an important role played by Ang II in the control of systemic haemodynamics in FFR and point to its interaction with adrenergic neurotransmission