The use of essential fatty acid deficient rats to study pathophysiological roles of prostaglandins. Comparison of prostaglandin production with some parameters of deficiency

In a retrospective study on essential fatty acid deficient (EFAD) rats used to study pathophysiological roles of prostaglandins (PGs), slight increases in the linoleic acid content of the diet were found to gradually restore the depressed growth rate and to increase the reduced endogenous PG production. These apparently poorly deficient animals had a serum triene tetraene (omega9:omega6) ratio much higher than the value of 0.4 used as a criterion for EFA deficiency by nutritionists. Changes in body weight, serum omega9:omega6 and platelet PG production were not correlated with each other. Feeding rats on a diet containing less than 0.1 mg/g/linoleic acid led to decreasing platelet PG production as the degree of EFA deficiency increased. At this high level of deficiency, a serum omega9:omega6 ratio of 6 or over was achieved. This high ratio may be taken as an indicator of the degree of EFA deficiency required for studies on PG deprivation, but PG production by the tissue investigated or by platelets should preferentially be measured.