Effect of cortisol on utilization and hepatic release of glucose in the marsupial brush-tailed opossum, Trichosurus vulpecula

Brush-tailed opossums were prepared surgically with indwelling heatic and jugular venous catheters for blood sampling without disturbance in the conscious state. Hepatic extraction of Rose Bengal was 21 +3 (s.d.) % and hepatic clearance, used as a measure of hepatic blood flow, was 42.5 +7 ml/kg/min. Hepatic relaease of new glucose, calculated from the thorias vena caval-hepatic venous difference in glucose specific activity at equilibrium during i.v. infusion of [14C]glucose and hepatic blood flow, was 3.5 + o.0 mg/kg/mim. This was not changed by i.v. infusions of 10% ethanolic aline or cortisol in ethanolic saline, at 1mg/kg/h for 90 min, although the cortisol infusion caused the peripheral blood glucose concentration to rise form 56.5 + 7.3 to 83.2 + 10.3 mg/100ml. The rate of metabolic clearance of glucose fell from 6.1 +1.1 to 4.2 +0.9 ml/kg/min during i.v. cortisol infusion. Daily i.m. injection of 1 mg cortisol accetate/kg for 5 days caused an increase in hepatic new glucose release to 8.0 + 1.6 mg/kg/min. The findings support the propostion that, in the marsupial, the short-term effect of cortisol on plasma glucose concentration is due to inhibition of peripheral glucose utilization, whereas the long-term effect is due to increased hepatic glucose production.

Renal uptake of 131I-rose bengal in biliary atresia. A case report

Renal uptake of radio-iodinated rose bengal was studied in a 5-month-old infant, who was later found, at operation, to have biliary atresia. Prominent renal uptake, which could easily be mistaken for radioactivity in the bowel, was noted. While this pitfall in diagnosis has previously been described, it is thought worth while to stress this possible cause of misinterpretation.

Sequential liver and biliary tract scanning with 131I labelled Rose Bengal

131I labelled Rose Bengal is offered as an aid for estimating the functional state of the liver, gall bladder and patency of the biliary tree. When the tracer is injected intravenously, it is cleared from the blood by the polygonal cells of the liver, excreted into the bowel and discharged into the duodenum. The equipment used was a gamma camera and small digital image processing system with area of interest capability. The diagnostic criteria used were those of blood retention, maximum hepatic uptake, liver, gall bladder and biliary tree visualisation times and time of excretion into the duodenum. Preliminary results from the findings in 60 patients of whom 42 were jaundiced are presented to demonstrate the ability of the technique to disclose evidence indicating intra- or extrahepatic causes of jaudice. Of 33 patients with proven extrahepatic obstruction Rose Bengal scanning provided the correct evidence in 31 cases, the other two having intermittent obstruction by common bile duct stones. Of the 12 patients with proven diffuse parenchymal disease the technique disclosed the correct evidence in all cases. All four post-cholecystectomy patients with recurrence of symptoms showed good visualisation of the duct system and excretion into the bowel.

Hepatic portoenterostomy (the Kasai operation) for biliary atresia

Twenty-two infants and children with extrahepatic biliary atresia were treated by Kasai's hepatic portoenterostomy operation since 1972. Postoperative bile drainage occurred in 11 infants. Success never was obtained in patients older than 12 weeks nor in the absence of microscopic biliary ductules in the excised fibrotic remnant of the extrahepatic bile ducts. With these exclusions almost 90 percent of infants with biliary atresia had sustained bile drainage after operation. In the early cases, ascending cholangitis was a major and recurrent complication with sequellae in many instances of permanent jaundice and probably irreversible liver damage. A new and simple modification of Kasai's original operation has prevented this complication thus far. Despite apparently normal bile drainage, postoperative studies by transhepatic cholangiography in some of these patients have demonstrated a grossly abnormal hepatobiliary intrastructure, suggesting that an underlying liver involvement may be present in biliary atresia.

Rapid transfer of folic acid from blood to bile in man, and its conversion into folate coenzymes and into a pteroylglutamate with little biological activity

1. [3H]Folic acid infused intravenously into patients with biliary fistulae appeared promptly in bile, coincident with 131I-labelled Rose Bengal injected simultaneously. The radioactivity was distributed among several fractions of biological folates present in bile and was associated with folic acid and with an unidentified folate which chromatographed on DEAE-Sephadex close to 10-formyltetrahydrofolyl monoglutamate.

2. Based on affinity for DEAE-Sephadex and support of growth of Lactobacillus casei, Streptococcus faecalis and Pediococcus cerevisiae, we have tentatively identified some of the folates of human bile as 10-formyltetrahydrofolate, 10-formylfolate, 5-formyltetrahydrofolate, 5-methyltetrahydrofolate and tetrahydrofolate or 5,10-methylene tetrahydrofolate. After infusion of folic acid, the formyltetrahydrofolates increased more rapidly than did 5-methyltetrahydrofolate.

3. The unidentified radioactive folate contained both the pteridine and p-aminobenzoate portions of folate. It appeared not to support growth of the test microorganisms and not to be bound to a protein or a chain of γ-glutamates. It was present in the bile of a dog injected with [3H]folic acid but was absent from extracts of liver. This material may be a transport form of folate or a special modification imposed on folic acid during transport across the liver.

Studies on the inhibition of clearance of organic dyes by Saramycetin

1. Saramycetin, a polypeptide antifungal antibiotic has been found to retard the clearance of sulphobromophthalein (BSP) in man. An explanation for this observation was sought in several lower species.2. Doses of Saramycetin without effect on the other standard tests of hepatic function or on hepatic morphology profoundly altered the disposition of BSP and several other dyes in mice and dogs.3. Saramycetin strongly inhibited the hepatic enzyme which conjugates BSP to reduced glutathione, provoked a regurgitation of BSP from the liver into the bloodstream, and was anticholeretic in the dog.4. These diverse actions of Saramycetin may, in concert, explain the altered clearance of BSP. It is suggested that low doses of Saramycetin exert a pharmacological effect on certain hepatic excretory processes, whereas high doses are toxic.