SUSTAINED ELEVATION IN CIRCULATING CATECHOLAMINE LEVELS DURING POLYMICROBIAL SEPSIS

Although studies have indicated that the levels of catecholamines incr ease during sepsis, it remains unknown whether the elevated levels of epinephrine, norepinephrine, and dopamine observed in early sepsis are sustained during late, hypodynamic stages of sepsis. In this study, r ats were subjected to sepsis by cecal ligation and puncture (CLP, i.e. , polymicrobial sepsis). Immediately after CLP or sham operation, anim als received 3 mL/100 g body weight normal saline subcutaneously. At . 5, 2, 10 (i.e., early sepsis), or 20 h (late sepsis) after CLP, blood samples were drawn and the plasma was separated. Plasma levels of epin ephrine, norepinephrine, and dopamine were determined using a [H-3]-ra dioenzymatic assay. The results indicate that plasma levels of epineph rine, norepinephrine, and dopamine increased significantly as early as .5 h after CLP. The increase in catecholamine levels persisted throug hout the study periods. Thus, circulating levels of catecholamines wer e elevated in both early and late stages of polymicrobial sepsis. Thes e results suggest that the increased catecholamine levels at .5-10 h a fter CLP may contribute to the hypermetabolic conditions that occur du ring early, hyperdynamic sepsis. However, there is a lack of an associ ation between the elevated plasma catecholamine levels and hypometabol ic/hypodynamic state in late sepsis.