HIGH AMMONIA DIET - ITS EFFECT ON THE GLIAL FIBRILLARY ACIDIC PROTEIN(GFAP)

The effect of a recent hyperammonemic model, consisting of a high ammo nia diet for 3, 7, 15, 45, and 90 days, on glial fibrillary acidic pro tein (GFAP) in the rat spinal cord and on blood ammonia levels has bee n studied. The high ammonia diet was prepared by mixing a standard dic t with ammonium acetate (20% wt/wt); in addition, 5 mM of ammonium ace tate was added to the water supply. GFAP contents were determined by m eans of immunoblotting analysis. The results demonstrated that this hi gh ammonia diet model neither induces significant changes in GFAP immu noreactivity, nor modifies total protein concentration, and only induc es significant blood hyperammonemic levels in the first days of treatm ent. An adaptative response to the diet is suggested and discussed to explain these results. A relation between ammonia and GFAP expression is suggested because transient hyperammonemia induces transient, altho ugh no significant, changes on GFAP expression.