EFFECTS OF INFLAMMATION-ASSOCIATED ACUTE-PHASE RESPONSE ON HEPATIC AND RENAL INDEXES IN THE HORSE

Objectives To determine the effect of an acute soft tissue inflammator y response on biochemical and haematological indices of hepatic and re nal function in the Thoroughbred horse. Procedure Soft tissue inflamma tion was induced in four Thoroughbred horses by intramuscular injectio ns of Freund's complete adjuvant. The horses were clinically examined and blood and urine samples were collected before and after the adjuva nt injections. Biochemical and haematological indices were measured in samples collected and used to determine the onset of the acute-phase response and to assess hepatic and renal function at this time. Result s After adjuvant injection, significant increases (P < 0.01) in total white (13.1 +/- 1.4 x 10(9)/L) and neutrophil (10.2 +/- 1.2 x 109/L) c ell counts, rectal temperature (39.7 +/- 0.5 degrees C) and various pl asma protein concentrations, including fibrinogen (6.6 +/- 1.2 g/L), h aptoglobin (1.3 +/- 0.1 g/L) and total protein (88.1 +/- 2.7 g/L), ind icated the induction of an acute-phase response. This corresponded wit h significant reductions (P < 0.01) in the plasma elimination half-liv es (t(1/2 beta)) sodium bromosulphthalein (3.13 +/- 0.05 to 2.82 +/- 0 .07 min) and sodium sulphanilate (38.29 +/- 4.04 to 19.60 +/- 5.68 min ) and reductions in the plasma activities of aspartate aminotransferas e, glutamate dehydrogenase, creatine kinase, alkaline phosphatase, gam ma glutamyl transferase; the urinary creatinine clearance ratios of so dium, chloride and potassium; and the urinary gamma glutamyl transfera se-to-creatinine clearance ratios. (All values mean +/- SD.) Conclusio ns The effects of the acute-phase response on indices of hepatic and r enal function in the horse suggest that the disposition of pharmacolog ical agents administered at this time may be altered and that indices of acute inflammation should be interpreted cautiously.