EFFECTS OF TRIIODOTHYRONINE ON CANINE HEPATIC ISCHEMIA CAUSED BY PRINGLE MANEUVER

Background. A significant reduction in the serum concentration of trii odothyronine is frequently observed in surgical stress and may influen ce the severity and prognosis of the underlying disease. Methods. Alte rations of thyroid hormone levels and effects of triiodothyronine were evaluated in the shock state after Pringle's maneuver for 60 minutes in dogs. Triiodothyronine (1 mug/kg/hr) was infused intravenously for 3 hours after declamping in the triiodothyronine-treated group. The ef fect of triiodothyronine on hepatic mitochondrial function was investi gated by measuring the arterial ketone body ratio (AKBR). Results. In the control group (n = 6) the low triiodothyronine syndrome was observ ed and progressive deterioration of AKBR and standard liver functions represented by aspartate aminotransferase, glutamic-pyruric transamina se, and lactic dehydrogenase were noted after declamping. All dogs wen t into shock and died within 24 hours. By contrast, in the triiodothyr onine-treated group (n = 6), hemodynamics were stabilized and standard liver functions were maintained favorably (p < 0.01). AKBR was fully restored to the preischemic liver within 30 minutes after declamping, with a decrease in serum lactate levels (p < 0.05). All dogs survived at least 7 days after operation (p < 0.01). Conclusions. These results indicate that triiodothyronine has beneficial effects on cytoprotecti on, hemodynamics, and hepatic energy metabolism in the ischemic liver injury. Furthermore, it improves survival in the shock state after Pri ngle's maneuver.