Feeding dogs or rats a diet supplimented with the sugar fructose enhances the development of insulin resistance and hypertension. Due to the kidney's role in the regulation of blood pressure, experiments were designed to test the effects of fructose feeding on renal arteries in vitro. Mongrel dogs were fed either a standard diet or a diet where 60% of the caloric intake came from fructose for a period of 7 or 21 days. On the day of the experiment renal arteries were removed from the dog, cut into rings and suspended into organ chambers for measurement of changes in isometric force. In half of the rings the endothelium was deliberately removed. Also some of the rings were treated with the prostaglandin inhibitor Indomethacin (IND). Renal arteries from fructose fed dogs, when compared to control dogs, had significantly (p<0.05) reduced contractions to electrical field stimulation in rings denuded of their endothelium. Treatment with IND amplified this effect. Fructose feeding of IND treated rings without endothelium also reduced contractions to the a, agonist phenylephrine, but had no effect on contractions to the ot2 agonist UK14304. In control dogs treatment with IND significantly (p<0.05) altered the contractions to electrical field stimulation. In rings with endothelium contractons were reduced and in rings without endothelium contractions were increased. Also in control dogs contractions to phenylephrine were reduced in IND treated rings without endothelium. Conclusions: 1) Fructose feeding reduces sympathetic induced vasoconstriction of renal arteries. 2) Prostaglandins modulate a, adrenergic generated contractions in smooth muscle cells of the renal artery. Supported by NIH grant HL16496.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology