Experimental bacteremia and hepatic nutrient blood flow

To study altered hepatic nutrient blood flow during the early phases of bacteremia, Sprague-Dawley rats (250-350 gm) underwent carotid cannulation; 24 hr later, they received an intravascular infusion of 2.5 X 10(8) Escherichia coli (LD70) over 45 min. Controls were anesthetized and cannulated only. Experimental and control animals then received a flow-dependent dose of indocyanine green (5 mg/kg) via the cannula, and arterial blood was sampled at 3, 4, 5, 6, 7, and 8 min after. Separate groups of animals were studied at 3 and 6 hr after bacteremia. The half-life (t1/2) of indocyanine green clearance was then determined at each time period, with t1/2 representing an estimation of total hepatic nutrient blood flow. Results indicated a prolonged t1/2 at both time periods in the bacteremic rats. Hepatic histology from plastic-embedded sections appeared to reveal fibrin, platelets, and leukocyte fragments within the sinusoids. From these data, we conclude that reduced nutrient blood flow occurs during experimental bacteremia prior to systemic changes of arterial pressure.