Dietary fatty acid supplementation modulates the urinary excretion of calcium and oxalate in the rat. Insight into calcium lithogenesis.
BACKGROUND
An anomalous plasma phospholipid polyunsaturated fatty acid composition has been reported in calcium nephrolithiasis, and was proposed to play a crucial role in the pathogenesis of hypercalciuria and hyperoxaluria, well-known risk factors for lithogenesis.


METHODS
To confirm this hypothesis, we administered rats three different diets rich in coconut, soybean and fish oils, and evaluated their effect on plasma urinary calcium and oxalate excretion, since the quality of fatty acids represents an important factor able to influence the activity of delta-6-desaturase, the rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acids.


RESULTS
In comparison with coconut and fish oil, dietary supplementation with soybean oil increased plasma phospholipid arachidonic acid and serum 1,25-vitamin D(3) values, as well as renal tissue calcium content and urinary excretion of sodium, oxalate and calcium.


CONCLUSIONS
Our findings demonstrate that the quality of fatty acids may modify the urine excretion of calcium and oxalate, confirming our previous hypothesis of a pathogenetic link between cellular membrane phospholipid polyunsaturated fatty acid composition and calcium nephrolithiasis. In addition, our study provides new insights into the relationship between dietary, environmental factors and renal stone disease.
Department of Medical-Surgery Sciences, Policlinico Universitario, University of Padua, Via Giustiniani 2, I-35120 Padua, Italy. bruno.baggio@unipd.it
Bruno
B
Baggio
Alessandro
A
Budakovic
Giovanna
G
Priante
Giovanni
G
Gambaro
Enzo
E
Manzato
Saeed
S
Khan
D000818:Animals; D001095:Arachidonic Acids / Q000097:blood; D002118:Calcium / Q000652:urine*; D002762:Cholecalciferol / Q000097:blood; D004041:Dietary Fats / Q000008:administration & dosage*; D019587:Dietary Supplements; D005227:Fatty Acids / Q000008:administration & dosage*; D008297:Male; D019815:Oxalic Acid / Q000652:urine*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000652:urine
D001095:Arachidonic Acids; D004041:Dietary Fats; D005227:Fatty Acids; D002762:Cholecalciferol; D019815:Oxalic Acid; D012964:Sodium; D002118:Calcium