FISH OIL FEEDING SELECTIVELY ATTENUATES CONTRACTILE RESPONSES TO NORADRENALINE AND ELECTRICAL-STIMULATION IN THE PERFUSED MESENTERIC RESISTANCE VESSELS OF SPONTANEOUSLY HYPERTENSIVE RATS

1. The mechanism of the antihypertensive effects of n-3 fatty acids were examined in spontaneously hypertensive rats (SHR) by feeding 'Max EPA' fish oil or hydrogenated coconut oil and determining the responses of perfused mesenteric resistance vessels to various contractile agents and peri-arterial nerve stimulation. 2. Fish oil feeding for 4 weeks caused a decrease in the responses to exogenous noradrenaline and electrical nerve stimulations but had no significant effect on vasopressin and KCl (80 mmol/L) induced contractions. 3. These results provide direct evidence for specific attenuation of vascular responses to sympatho-adrenal stimulation in resistance vessels following fish oil feeding and may account for the antihypertensive effects seen in humans and in some forms of hypertension in rats.