Dietary effects on platelet aggregation

Abstract

A major limitation to Single-cell protein (SCP) as a human food is its high nucleic acid content, the purine moiety of which is metabolised to uric acid. Rats given a Fusarium mould (SCP) in diets containing oxonate, a uricase inhibitor, developed elevated plasma and kidney uric acid concentrations after 21 d, which were related to the level of dietary mould.An association between hyperuricaemia and cardiovascular disease has been suggested, but the results of experimental and epidemiological studies remain equivocal. Platelet aggregation was measured in hyperuricaemic rats and a significant correlation was demonstrated between plasma uric acid concentration and platelet aggregation (maximum rate of aggregation (VAmax) for ADP-induced aggregation r = 0.88; thrombininduced VAmax r = 0.74). A linear relationship was shown between the level of dietary mould and platelet aggregation (ADP-induced VAmax p &lt; 0.01; thrombin-induced VAmax p &lt; 0.001). Furthermore a time lag, exceeding the life-span of rat platelets, was observed between the development of hyperuricaemia and the increase in aggregation.The effect of other dietary components on platelet aggregation in rats has been examined. Aggregation was reduced progressively when rats were given low-protein diets (50 g casein/kg), but not when 90 or 130 g casein/kg diet was given.Neither the degree of saturation of dietary fat, nor the level of dietary fat, nor the nature of the dietary sugar (glucose, fructose or sucrose) altered platelet aggregation significantly, although with a high dietary sugar content aggregation tended to be reduced.The possible interaction between dietary protein, fat and carbohydrate in their effects on platelet aggregation was examined. Platelet aggregation was substantially reduced in low-protein groups regardless of the dietary sucrose or fat content. Among low-protein groups, aggregation was increased in high-fat groups, but this effect was not observed when the dietary sucrose was also increased. No other effects were observed.</p