Measurement of Hepatic Blood Flow in the Dog by the Bromsulphalein Method 12

Abstract

Estimation of hepatic blood flow by the bromsulphalein method appears to be based upon meager experimental evidence. Bradley, Ingelfinger, Bradley, and Curry (1) proposed a formula for the estimation of hepatic blood flow in man by measuring the hepatic extraction of bromsulphalein. Myers (2) compared the hepatic blood flow obtained by this method with the hepatic flow determined by urea formation. These An indwelling needle or catheter was also placed in a branch of the femoral artery. All animals were heparinized, 5 mg./Kg. Blood pressures were recorded continuously by Statham strain gauges simultaneously from the femoral artery, right heart, and hepatic vein. A priming dose of bromsulphalein (BSP) was administered to raise the plasma level rapidly and to shorten the time required for equilibration. The priming dose of BSP was followed immediately by infusion of BISP at a constant rate for a period of 80 minutes.In order to maintain a peripheral BSP concentration of less than -mg. per cent or greater than 1 mg.per cent, two rates or two concentrations of BSP infusions were given. The flow was controlled by the use of a Graubard Peterson flowrator. A sample of the infusion fluid was always taken for later analysis. Hepatic venous and peripheral arterial samples were withdrawn simultaneously at 10-minute intervals during the 40 to 80 minutes of each observation.Five ml. of blood were collected in a dry syringe following preliminary flushing of the catheter by withdrawal of several ml. of blood. Ilemolyzed samples were discarded. The hematocrit value was determined by the usual Wintrobe tube technique from samples of blood obtained at the midpoint of measurements of hepatic blood flow. Blood samples were also obtained from the femoral artery and right heart for the estimation of cardiac output by the Fick principle 60 minutes after the infusion had begun. The data on blood pressures and cardiac outputs are being reported in a separate communication. At the end of each period of observation incisions were sutured, 300,000 units of procaine penicillin administered and the dog returned to its cage. No animal was employed either for other observations or repeated hepatic observations until at least two or more weeks had elapsed.BSP was measured calorimetrically in the macro unit of the Evelyn photoelectric colorimeter using filter 580.The calibration curve and the BSP solutions employed in all experiments were prepared from pure BSP powder (Hynson, Westcott, and Dunning).One ml. of plasma was pipetted into an Evelyn colorimeter tube and the volume made up to 10 ml. with isotonic saline. After the initial "blank" reading, 2 drops of concentrated NaOH were added, the mixture well agitated, and a reading taken within one minute of adding the alkali. The BSP concentration was obtained from the galvanometer reading and the calibration curve. All determinations were made in duplicate.433

The Physiological Significance of the Secretion of Endogenous Insulin Into the Portal Circulation. Iii. Evidence for a Direct Immediate Effect of Insulin on the Balance of Glucose Across the Liver*†

“…The effect of the establishment of a portacaval shunt on hepatic blood flow and hepatic glucose metabolism In the present studies control hepatic blood flow in dogs with portacaval shunts averaged 281 ml per minute or 15 ± 2.8 ml per kg per minute. In 17 other studies in dogs without portacaval shunts, which were performed in this laboratory utilizing the same technics, hepatic blood flow averaged 38.3 ml per kg per minute, a value similar to that reported by others (42)(43)(44).…”

Partition of the venous return to the heart

“…The mean flows in the different series of experiments ranged from 25-3 to 33-0 ml./min/kg; our flows were higher than this (mean, 43.9 ml./ min/kg). Our results agreed more closely with the estimates of liver flow made by the BSP method on dogs with the chest intact (29-5-48.6 ml./min/kg) but, in general, our flows are higher than the majority of hepatic flows given in 376 PARTITION OF VENOUS RETURN Grab, Janssen & Rein (1929) Thermostromuhr 25*3 Blalock & Mason (1936) Measurement of 27*0 venous outflow Grindlay, Herrick & Mann (1941) Thermostromuhr 26*0 Selkurt (1954) Measurement of 33-0 venous outflow Werner & Horvath (1952) (42.0 Heineman, Smythe & Marks (1952) Flow in other veins Only a few measurements of azygos flow in the dog seem to have been made with the venae cavae unoccluded. Andreasen & Watson (1952) report one measurement of 18 ml./min in a dog which probably weighed about 10 kg.…”

Studies on bromsulphalein and cardiac output in the hepatectomized dog

“…When hepatic flows were corrected for the 20 % extrahepatic BSP loss, the values obtained were in close agreement with the data from other methods (Werner & Horvath, 1952 In five dogs a priming dose of 20 mg BSP was injected into a foreleg vein after hepatectomy, followed immediately by an infusion of 0.10 mg BSP/ml./min for 1 hr. In eleven dogs 20 mg of BSPwere injected into a foreleg vein, followed 20 min later by a 10mg injectionof BSP.…”

“…The preparation of the blood samples for the analysis of BSP was the same as previously described (Werner & Horvath, 1952). The concentration of BSP in the plasma of five dogs was determined in an Evelyn photoelectric colorimeter.…”