Hyperglycemia-induced cholestasis in the isolated perfused rat liver

Abstract

In a previous report we showed that cholestasis in diabetic rats is due in part to hyperglycemia. To gain information about the mechanism responsible for this phenomenon, bile flow was studied in isolated perfused rat livers. The perfusion media were modified erythrocyte-free Krebs-Henseleit solutions. Under these experimental conditions, no cholestasis was observed in isolated rat livers obtained from rats treated with streptozotocin (6 mg/100 gm body wt) 6 days before the experiments. We then proceeded to use normal animals. The composition of the perfusion media was modified to maintain the osmolality even after increasing D-glucose concentrations from 0 to 35 mmol/L. Bile flow was not affected with doses up to 15 mmol/L D-glucose. Beyond a threshold value for plasma D-glucose concentrations between 15 and 20 mmol/L, cholestasis was observed. Using D-glucose analogs such as L-glucose and 3-O-methyl-D-glucose, bile flow was also reduced (by 0.54 and 0.53 microliters/min/gm liver, respectively). Isosmotic sucrose-containing perfusion media were also observed to impair bile flow (by 0.66 microliters/min/gm liver). However, i-erythritol and D-mannitol failed to inhibit bile formation. The study of bile/plasma concentration ratios determined using tracer amounts of radioactive sugars indicated that this value was much lower for cholestatic sucrose (0.11) and L-glucose (0.31) than for noncholestatic i-erythritol (0.99) and D-mannitol (0.98). Cholestasis was partly reversed after induction by 35 mmol/L D-glucose if perfusion media were replaced by sugar-free ones, but also by media containing 25 mmol/L D-glucose. Insulin given during the perfusion with sugar-free media was observed to have no effect on bile flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile acid-induced modifications in DNA synthesis by the regenerating perfused rat liver,

“…Perfusion of Regenerating Rat Liver. The viability of regenerating perfused rat liver preparations (see Materials and Methods) was similar to that previously reported for nonregenerating livers (26). Table 1 shows that the net amounts of DNA and protein content per gram of whole tissue were not different between the two types of preparations (regenerating and nonregenerating).…”

“…When different experimental groups of regenerating rat livers were compared with control nonregenerating rat livers, no significant changes were observed in these viability parameters. Values were similar to those previously obtained in our laboratory for isolated nonregenerating liver preparations (26). Values (mean 2 S.E.M.)…”

Bile acid-induced modifications in DNA synthesis by the regenerating perfused rat liver

“…The viability of regenerating perfused rat liver preparations (see Materials and Methods) was similar to that previously reported for nonregenerating livers (26). Table 1 shows that the net amounts of DNA and protein content per gram of whole tissue were not different between the two types of preparations (regenerating and nonregenerating).…”

“…When different experimental groups of regenerating rat livers were compared with control nonregenerating rat livers, no significant changes were observed in these viability parameters. Values were similar to those previously obtained in our laboratory for isolated nonregenerating liver preparations (26) Experimental Protocol. After an equilibration period of 10 min with the perfusion medium, we maintained recirculating perfusion for an additional 60 min; this was considered the experimental period (Fig.…”

Effect of maternal cholestasis on the kinetics of bile acid transport across the canalicular membrane of infant rat livers

“…The hepatic artery was ligated and the common bile duct, portal vein and inferior vena cava were cannulated. Livers were perfused in situ in a prewarmed (38ЊC) cabinet by an adaptation (Marin et al 1991) of the classical method of Miller et al (1951). The recirculating perfusion medium was 150 ml of a modified Krebs-Henseleit solution containing the following in mM: 120 NaCl, 5 KCl, 1.29 CaCl 2 , 0.65 MgSO 4 , 25 NaHCO 3 , 1.17 KH 2 PO 4 , 5.0 D-glucose and gentamicin sulphate (100 mg/l).…”