EVALUATION OF 4 ANIMAL-MODELS OF INTRARENAL CALCIUM DEPOSITION AND ASSESSMENT OF THE INFLUENCE OF DIETARY SUPPLEMENTATION WITH ESSENTIAL FATTY-ACIDS ON CALCIFICATION

Firstly, to determine a satisfactory animal model for induction of int rarenal calcification, a study of four previously described animal mod els of intrarenal calcification was carried out which showed that intr aperitoneal injection of 10% calcium gluconate into female Sprague-Daw ley rats was most effective. We then investigated the hypothesis that dietary supplementation with essential fatty acids could reduce the in trarenal calcification developing as a result of intraperitoneal calci um injection. Using a combination of fish oil and evening primrose oil , we demonstrated a significant difference in renal parenchymal calcif ication, which was 940 +/- 240 mu g Ca/g dry weight renal parenchyma i n unsupplemented animals and 320-370 +/- 55-65 mu g Ca/g dry weight re nal. parenchyma in supplemented animals (means +/- SEM, P < 0.005). It was also demonstrated that there was synergism between eicosapentaeno ic acid (EPA) and gamma-linolenic acid (GLA): dietary supplementation with a combined oil preparation containing 27 mg/ml EPA and 67 mg/ml G LA mixed as 2% with food was as effective as oils containing either 40 0 mg/ml EPA or 80 mg/ml GLA mixed as 4% of food.