EFFECTS OF DOPAMINE, DOPEXAMINE AND DOBUTAMINE ON RENAL EXCRETORY FUNCTION DURING EXPERIMENTAL SEPSIS IN CONSCIOUS RATS

Background: Acute renal failure is a frequent complication in human se psis. Various inotropic drugs are often used to improve central haemod ynamics and renal function. The differential preservative role of the most commonly used inotropic drugs on renal function, in this conditio n, has previously not been extensively studied. The aim of this experi mental animal study was therefore to compare the preserving effects of dopamine, dopexamine, dobutamine and saline on renal excretory functi on, after induction of sepsis in conscious rats. Method: The effects o f dopamine (DA) (2.5 mu g.kg(-1).min(-1); n = 11), dopexamine (DX) (1 mu g.kg(-1).min(-1); n = 10), dobutamine (DB) (5 mu g.kg(-1).min(-1); n = 10) and saline (n = 13) on the glomerular filtration rate (GFR), u rine flow (UF), sodium excretion (SE) and fractional urinary excretion of sodium (FUENa) were studied and compared in conscious rats subject ed to a 1-h infusion of live E. coli bacteria (10(9)/h). Results: In t he saline-treated control group, bacteria infusion decreased GFR, UF, SE and FUENa by 31%, 53%, 51% and 36% respectively, associated with a 16% decrease in mean arterial pressure (MAP), and a 10% increase in he art rate (HR). In the post-E. coli treatment period, the fall in MAP w as less pronounced with DX compared to both DB and control, while ther e was no difference between DX and DA. The increase in HR was most pro nounced with DB. GFR decreased to a lesser extent with DX compared to DA, DB and control. UF and SE were better maintained with DX compared to DB and control, while there was no difference in FUENa between the groups. Conclusion: We conclude that dopexamine, to a greater extent t han dopamine and dobutamine, improves renal excretory function in expe rimental septic shock.