Reduced water and sodium intakes associated with high levels of natriuretic factor following common bile duct ligation in the rabbit

Abstract

Renal failure complicating obstructive jaundice (OJ) is probably linked to reduction of the extracellular water compartment. To elucidate the mechanism by which OJ leads to isotonic water depletion we studied a group of rabbits with OJ after common bile duct ligation (n = 17) and another group of sham operated rabbits (n = 14) for 10 days. Water intake and balance for two study periods (1-4 and 7-10 days after operation) were calculated. Renal function, sodium balance and plasma atrial natriuretic factor were determined on the fourth and tenth days after operation. Water intake and balance were lower in the OJ group both in the first study period (230 versus 519 ml/days 1-4, P less than 0.001; and -2.4 versus 219 ml/days 1-4, P less than 0.0001 respectively) and in the second study period (260 versus 865 ml/days 7-10, P less than 0.0001; and 11 versus 379 ml/days 7-10, P less than 0.0001 respectively). Sodium intake was negligible in the OJ group both on day four (0.73 versus 7.15 mM/24 h, P less than 0.0001) and on day 10 (0.78 versus 15.78 mM/24 h, P less than 0.0001). As a result plasma osmolality did not change. Day 10 urine osmolality and osmolar clearance were reduced in the OJ group (653 versus 1103 mOsm/kg, P less than 0.0001 and 0.09 versus 0.25 ml/min, P less than 0.0001 respectively) together with a decreased creatinine clearance (3 versus 11 ml/min, P less than 0.0001). Atrial natriuretic factor was increased in jaundiced rabbits (day 4, 22.7 versus 7.5 fmol/ml, P less than 0.0001; and day 10, 26.5 versus 11.2 fmol/ml, P less than 0.02). These findings suggest that OJ leads to an isotonic volume depletion resulting from abnormalities of the extracellular volume regulating mechanisms. These appear to be secondary to an inappropriate elevation of the atrial natriuretic factor plasma concentration.

Alteration of the renal regulatory hormonal pattern during experimental obstructive jaundice

“…However, studies with similar experimental models showed a significant reduction in creatinine clearance at four days of biliary ligation (11,12), and a rise in serum creatinine in animals submitted to one week of OJ (7,13). Our study corroborated previous studies (14,25) that showed that OJ causes a decrease in sodium excretion and lower sodium concentrations in urine, which suggests increased sodium reabsorption in cholestatic rats. In addition, our study could not show a clear relationship between sodium excretion or sodium concentration in urine and ANP concentration in urine.…”

“…Nevertheless, it could be feasible that the tendency of ANP to rise could be statistically significant at the longest time period of OJ. Another factor to bear in mind is that our experiment was conducted on rats, and studies with a rise on ANP have been published in humans (15) and in rabbits (14). Nonetheless, the concentration of renin and aldosterone in the serum increased in rats with biliary obstruction, though only aldosterone levels were statistically significant.…”

Randomized clinical trial of the effect of intravenous fluid administration on hormonal and renal dysfunction in patients with obstructive jaundice undergoing endoscopic drainage

“…This study confirms the finding of a paradoxical increase in plasma ANP concentration in patients with obstructive jaundice, and its decline after biliary drainage15. Basal plasma renin and aldosterone levels were in the normal to high range, suggesting a marginal reduction in plasma volume consistent with significant depletion in ECW in patients with jaundice8–15. This volume depletion was associated with hypoalbuminaemia, a common finding in malignant biliary obstruction16.…”

“…More emphasis has been put recently on the presence of extracellular water (ECW) depletion8–10 and myocardial dysfunction11, 12 as causes of haemodynamic and renal disturbances in patients with obstructive jaundice. Obstruction of the biliary tract is associated with a raised plasma concentration of atrial natriuretic peptide (ANP)13–15. This occurs despite moderate volume depletion, as shown by tracer dilution techniques8 and levels of endocrine markers, such as an increased plasma renin concentration15.…”

Prediction of renal dysfunction in patients with obstructive icterus

“…Prevalencija pojave renalne disfunkcije nije uslovljena benignom ili malignom etiologijom opstrukcije, kao ni dužinom trajanja ikterusa [15,16], što je pokazalo i istraživanje u našoj studiji.…”