Roles of trace amine-associated receptors in cardiovascular responses to dietary trace amines
Trace amines are produced endogenously and are consumed in the diet. Cheese, chocolate, yeast extract, soya bean products, fermented meats and alcoholic beverages contain high levels of the trace amines tyramine and beta-phenylethylamine. The ability of these dietary trace amines to constrict peripheral resistance vessels and to increase blood pressure is well-documented. Our research group has shown that tyramine and beta-phenylethylamine (beta-PEA) constrict the coronary artery, the main resistance blood vessel supplying the heart. We have also demonstrated recently for the first time that dietary trace amines can relax mesenteric resistance vessels, supplying blood to the intestine. We therefore propose that the vascular response to dietary trace amines will differ between resistance vessels in different organs. Resistance blood vessels regulate arterial blood pressure and blood flow within our organs. These amines are traditionally regarded as indirectly acting sympathomimetic amines in that they exert their effects on the body through the release of the sympathetic nerve transmitter substance, noradrenaline.
Our previous studies have shown that this is an oversimplification and that trace amine-dependent changes in resistance vessel diameter are not mediated by classical neurotransmitter receptors, including adrenoceptors, but through receptors yet to be identified. Our preliminary data suggests these are ‘trace amine-associated receptors’ (TAARs).
Aims of Project
This project will characterize the cardiovascular responses to trace amines in vivo and in isolated resistance vessels in various vascular beds to determine the roles of classical amine receptors and TAARs. The knowledge gained will inform how trace amines affect the cardiovascular system when adrenoceptors are compromised by disease or by therapeutic regimens, and will influence the choice of food we consume. Since changes in resistance vessel tone influence arterial blood pressure we also propose that these new receptors could be targets for novel anti-hypertensive medications.
British Heart Foundation