Effects of Rat Bile Infusion on Renal Function in Rats

Abstract

The influence of rat bile infusion on renal function in rats and the possible role of bile-induced hemolysis in these effects were examined. The hemolytic action of rat bile and some bile salts were determined in vitro. After the i.v. infusion of rat bile (70 mg freeze-dried powder/2.55 ml) into pentobarbitone-anesthetized rats, the urine, sodium and potassium excretion rates were reduced more than half, which was due to the decrease of glomerular filtration rate and increase of tubular water and sodium reabsorption. A fall in blood pressure, a rise in hematocrit, and hemolysis were also found. Infusion of hemolysed (30 µl RBC) solution produced by distilled water and then made isotonic caused a short-duration increase in renal excretion and glomerular filtration rate, and the blood pressure was unchanged. Infusion of a rat bile-hemolysed solution after removal of bile acids with cholestyramine increased renal excretions at first with reduction thereafter. Infusion of the rat bile-hemolysed solution treated with barium sulfate produced a renal response very similar to rat bile alone. It is proposed that two factors are involved in the renal response after bile infusion, namely bile acid-induced hemolysis producing diuresis with natriuresis, and bile acid-induced antidiuresis and antinatriuresis, possibly due to a direct renal effect.

Renal Functional Alterations in Extrahepatic Cholestasis: Can Oxidative Stress Be Involved?

“…The decrease in sodium and potassium uri nary outputs found soon after BDL might be due to hemodynamic rather than specific re nal alterations [5,18], In fact, the variations in these electrolytes were consensual and in contrast to those for the hematocrit.…”

“…Recently, attention has been focused on the possible role of lipid peroxidation [3,5,19,20]. We evaluated TBARS, PLAt and total GSH.…”

“…In the absence longed cholestasis, characterized by the reten tion of bile compounds, may cause renal dam age (reduction in renal hemodynamics, im pairment of renal excretion of water and salts and sensitization of the kidney to anoxic dam age) which sometimes leads to renal failure [1][2][3][4][5].…”

“…The pathophysiological cause of renal damage in the course of bile flow impairment is not well understood, even if several phe nomena, such as increased access of various bile constituents into the kidney (bilirubin and bile salts), have been suggested [1,3,5]. The nephrotoxic mechanism of these sub stances appears to be either indirect, because of their proinflammatory capacity (cytokines, acute-phase proteins, or leukocyte activation) or direct, because of hemolysis [6], Endotoxemia may also have a toxic effect on renal function; clinical and experimental works have focused on the role of endotoxins gut absorption in causing renal impairment during cholestasis, as well as in chronic renal failure [7][8][9][10].…”

“…It was recently suggested that lipid peroxi dation is a noxious agent in renal damage fol lowing bile flow impairment [5].…”