Effects of Chronic Ochratoxin A and Citrinin Toxicosis on Kidney Function of Single Comb White Leghorn Pullets

Abstract

The objectives of the present study were to examine the effects of repeated or chronic ochratoxin A (OA) and citrinin exposure, and to determine if severe ochratoxicosis permanently alters renal function in pullets. The OA-treated birds were injected intramuscularly (breast muscle) with a 1 mg/mL solution of OA at a dose of .25 mg/kg BW or .5 mg/kg BW. Citrinin-treated birds were injected with a 6 mg/mL solution of citrinin at a dose of 6 mg/kg BW. Control birds received an equal volume injection of the citrinin and OA solvent, 100% ethanol, at a dose of 1 mL/kg BW. Kidney function was evaluated after 10 consecutive days of OA, citrinin, or ethanol injection, and 2 wk following the final injections. Venous blood gas measurements were taken after the seventh day of injection.The OA increased urine flow rate, decreased urine osmolality, increased ion excretion (Na, K, Ca, P), increased water consumption, increased manure moisture, and caused a relative alkalosis when measured immediately after 10 days of OA injection. These effects of OA were not detected 2 wk later. Citrinin increased manure moisture, decreased plasma P, increased the clearance of para-aminohippuric acid, and had no consistent effect on blood acid-base parameters. The results suggest that OA may cause an osmotic diuresis by inhibiting tubular reabsorption of electrolytes. The data also suggest that the effects of OA may be reversible simply by discontinuing toxin administration. Although the citrinin-induced increase in manure moisture indicates that citrinin had an effect on renal function, renal function analysis suggests that even repeated exposure to high doses of citrinin may only have a short duration of diuretic action on the kidneys.