Regulation of lactate and pyruvate levels in perfusion medium by the isolated rat liver

Schimassek, H.

doi:10.1016/0024-3205(62)90097-8

Cited by 20 publications

(9 citation statements)

References 2 publications

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“…Scholz & Bucher (1965) have shown that the lactate/pyruvate ratio of the perfusate is a sensitive indicator of the metabolic condition of the isolated perfused liver. Under certain conditions this ratio reflects the NADH/NAD+ ratio in the cytoplasm of the perfused liver (Schimassek, 1962). In a series of five perfusion experiments the lactate/pyruvate ratios (physiological range 10-20) were 7.5±1 at the beginning, 10.6±0.8 after 4h and 14.3 ± 1.2 after 7h of perfusion.…”

Section: Resultsmentioning

confidence: 95%

The conversion of orotic acid into uridine 5′-monophosphate by isolated perfused normal and regenerating rat livers

Fausto

1972

Biochemical Journal

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The release of (14)CO(2) from [7-(14)C]orotic acid was measured in isolated perfused normal and regenerating rat livers. With some limitations, the release of (14)CO(2) from [7-(14)C]orotic acid can be used to estimate UMP synthesis in perfused livers. Isolated perfused livers rapidly pick up labelled orotic acid added to perfusate and convert most of it into UMP. Perfused regenerating livers produce approx. 2.5 times as much UMP/g of liver as do perfused normal livers. However, the absolute amount of orotic acid converted into UMP is higher in perfused normal livers than in perfused regenerating livers. Perfused regenerating livers do not differ in their orotic acid uptake and UMP synthesis from livers of comparable size in which regeneration is not taking place. The total amount of orotic acid taken up by the liver (rather than the rate of uptake) and the size of the liver appear to be the determining factors in UMP production. The results suggest that the decrease in liver size caused by partial hepatectomy may be in itself sufficient to account for an increase in the flow of metabolites in the pyrimidine pathway at the early stages of liver regeneration.

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Section: Resultsmentioning

confidence: 95%

The conversion of orotic acid into uridine 5′-monophosphate by isolated perfused normal and regenerating rat livers

Fausto

1972

Biochemical Journal

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“…All experiments with less than (2-5 ml/ 100 g liver)/hour were discarded. The ratio lactate/ pyruvate in the perfusion medium can be regarded as a valid criterion of the functional status of the liver (Schimassek, 1962(Schimassek, , 1963(Schimassek, , 1968. This parameter should have a value of about 10 for isolated rat and guinea-pig livers (Berg et al, 1970).…”

Section: Function Testsmentioning

confidence: 99%

“…The liver is the most significant organ for the metabolism of the cardiac glycosides (Okita, Talso, Curry, Smith & Geiling, 1955). Perfusing the isolated guinea-pig liver according to the method of Schimassek (1962Schimassek ( , 1963Schimassek ( , 1968 we investigated the excretion and metabolism of ouabain, digoxin, and digitoxin thus avoiding any interference by other factors, such as renal excretion, tissue distribution and so on. Guinea-pigs were chosen because the sensitivity of the heart muscle of this species to cardiac glycosides is similar to that of the human heart (Repke, Est & Portius, 1965).…”

Section: Introductionmentioning

confidence: 99%

Plasma concentration, uptake by liver, and biliary excretion of tritiated cardiac glycosides in the isolated perfused guinea‐pig liver

Kolenda

Lüllmann

Peters

et al. 1971

British J Pharmacology

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Summary1. Investigations were carried out on isolated perfused guinea-pig livers. Different doses of tritiated ouabain, digoxin, and digitoxin were added to the perfusion medium and the subsequent plasma elimination, hepatic uptake, and biliary excretion quantitatively measured. After the perfusion, extracts of liver, bile and plasma were subjected to thin layer chromatography in order to detect the radioactively labelled glycosides and their metabolites. 2. The ouabain concentration in the plasma approached the equilibrium stage within 45 minutes. At this time 40% of the administered dose had been taken up by the liver, and no further elimination occurred. The elimination curve for ouabain followed a simple exponential function. After 1 h the tissue medium (T/M) ratio was approximately 3. In bile hardly any radioactivity could be detected. Ouabain was therefore not excreted by the liver. 3. Up to 80% of the digitoxin was eliminated from the plasma within 4 hours. The elimination of radioactive material for the dose range studied could be described by a hyperbolic function. The T/M ratio in the liver varied with time. At the beginning it was as high as 10 and after 4 h reduced to approximately 3. After 45-60 min the concentration of radioactive material in the bile was 500 times as high as that in the plasma. Almost 70% of the administered radioactivity was excreted with the bile within 4 hours. At the end of the perfusion almost all the identifiable substances in plasma and bile were polar metabolites, as shown by thin layer radiochromatography. 4. Digoxin behaved similarly to digitoxin. 5. The findings led to the following hypothesis: uptake of cardiac glycosides into the liver cells occurs by a passive diffusion process and is related to their lipid solubility. On the other hand excretion in the bile occurs in general if polar metabolites are formed in the liver cells. IntroductionQualitatively, the effect of the clinically important cardiac glycosides ouabain, digoxin and digitoxin on heart muscle is approximately the same. Nevertheless considerable differences exist between the onset of action, the duration of the effect in the intact organism and the degree of accumulation in isolated organs. These differences are probably caused by the quite different fate of the three glycosides in

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“…Der Glucose-Spiegel bleibt praktisch konstant. Lactat und Pyruvat fallen im Medium (und im cytoplasmatischen Raum [3,18]) bis zur 2. Perfusionsstunde bis auf etwa 40 % ihres Ausgangs spiegels ab, um dann wieder in die Nähe des Ausgangspunktes anzu steigen [siehe auch 12].…”

Section: Diskussionunclassified

“…Perfusionsstunde bis auf etwa 40 % ihres Ausgangs spiegels ab, um dann wieder in die Nähe des Ausgangspunktes anzu steigen [siehe auch 12]. Ihre Relation, der Lactat-Pyruvat-Quotient, dessen Aufrechterhaltung als wesentliches Kriterium der Funktion betrachtet werden kann [3,18,20], bleibt jedoch während der ganzen Perfusionsdauer erhalten.…”

Section: Diskussionunclassified

Studien zum Austritt von Zell-Enzymen am Modell der isolierten, perfundierten Ratten-Leber

Herfarth¹,

Opitz²,

Vogell³

et al. 1966

Enzymol Biol Clin

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Das extracellulär entstehende Enzym-Muster bei hypoxischer Perfusion der isolierten Rattenleber wurde in Beziehung zu bekannten und zu gleichzeitig untersuchten Größen gesetzt. Dabei zeigte sich, daß die Austrittsraten der einzelnen Enzyme in erster Linie vom Konzentrationsgefälle Leber/Extracellularraum, in zweiter Linie vom Molekular-Gewicht der Enzyme und in dritter Linie von ihrer intracellulären Lokalisation abhängen. Weiterhin wurde der aus dem Typ des extracellulären Enzym-Musters gezogene Schluß, daß die Einzelzellschädigung hierbei nur leicht bis mäßig sei, durch das Verhalten der Metabolit-Spiegel im Perfusionsmedium und die morphologischen Befunde an der Leber bestätigt.

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Regulation of lactate and pyruvate levels in perfusion medium by the isolated rat liver

Cited by 20 publications

References 2 publications

The conversion of orotic acid into uridine 5′-monophosphate by isolated perfused normal and regenerating rat livers

The conversion of orotic acid into uridine 5′-monophosphate by isolated perfused normal and regenerating rat livers

Plasma concentration, uptake by liver, and biliary excretion of tritiated cardiac glycosides in the isolated perfused guinea‐pig liver

Studien zum Austritt von Zell-Enzymen am Modell der isolierten, perfundierten Ratten-Leber

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