Regulation der Sauerstoff-Aufnahme, der Mikrozirkulation und der Glucose-Abgabe durch zirkulierendes Noradrenalin in der perfundierten Rattenleber

TY - JOUR

T1 - Regulation der Sauerstoff-Aufnahme, der Mikrozirkulation und der Glucose-Abgabe durch zirkulierendes Noradrenalin in der perfundierten Rattenleber

AU - Beckh, Karlheinz

AU - Otto, Regina

AU - Ji, Sungchul

AU - Jungermann, Kurt

N1 - Funding Information: This work was supported by the Deutsche Forschungs-gemeinschaft, Bonn-Bad Godesberg. We thank the Smith-Kline-Dauelsberg Stiftung, G ttingen, for the travel grant to S.J., and Mr Willi Kraft for taking the photographs of Fig. 2.

PY - 1985

Y1 - 1985

N2 - The effect of noradrenaline on oxygen uptake, on periportal and perivenous oxygen tension at surface acini, on microcirculation and on glucose output were studied in isolated rat livers perfused at constant flow with Krebs-Henseleit-hydrogen carbonate buffer containing 5mM glucose and 2mM lactate. 1) Noradrenaline at 1μM concentration caused a decrease in oxygen uptake, while at 0.1 μM it led to an increase. Both high and low doses of noradrenaline decreased the tissue surface oxygen tension in periportal and ü after a transient rise ü in perivenous areas. 2) Noradrenaline at an overall constant flow caused an increase of portal pressure and an alteration of the intrahepatic distribution of the perfusate: at the surface of the liver and in cross sections infused trypan blue led to only a slightly heterogeneous staining after a low dose of noradrenaline but to a clearly heterogeneous staining after a high dose. 3) Both high and low doses of noradrenaline stimulated glucose release. 4) All effects could be inhibited by the α-blocking agent phentolamine. In conclusion, control of hepatic oxygen consumption by circulating noradrenaline is a complex result of opposing hemodynamic and metabolic components: the microcirculatory changes inhibit oxygen uptake; they dominate after high catecholamine doses. The metabolic effects include a stimulation of oxygen utilization; they prevail at low catecholamine levels. The noradrenergic control of glucose release is also very complex, involving direct, metabolic and indirect, hemodynamic components.

AB - The effect of noradrenaline on oxygen uptake, on periportal and perivenous oxygen tension at surface acini, on microcirculation and on glucose output were studied in isolated rat livers perfused at constant flow with Krebs-Henseleit-hydrogen carbonate buffer containing 5mM glucose and 2mM lactate. 1) Noradrenaline at 1μM concentration caused a decrease in oxygen uptake, while at 0.1 μM it led to an increase. Both high and low doses of noradrenaline decreased the tissue surface oxygen tension in periportal and ü after a transient rise ü in perivenous areas. 2) Noradrenaline at an overall constant flow caused an increase of portal pressure and an alteration of the intrahepatic distribution of the perfusate: at the surface of the liver and in cross sections infused trypan blue led to only a slightly heterogeneous staining after a low dose of noradrenaline but to a clearly heterogeneous staining after a high dose. 3) Both high and low doses of noradrenaline stimulated glucose release. 4) All effects could be inhibited by the α-blocking agent phentolamine. In conclusion, control of hepatic oxygen consumption by circulating noradrenaline is a complex result of opposing hemodynamic and metabolic components: the microcirculatory changes inhibit oxygen uptake; they dominate after high catecholamine doses. The metabolic effects include a stimulation of oxygen utilization; they prevail at low catecholamine levels. The noradrenergic control of glucose release is also very complex, involving direct, metabolic and indirect, hemodynamic components.

KW - Rat liver

KW - glucose output

KW - microcirculation

KW - noradrenaline

KW - oxygen uptake

KW - surface oxygen tension

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U2 - https://doi.org/10.1515/bchm3.1985.366.2.671

DO - https://doi.org/10.1515/bchm3.1985.366.2.671

M3 - Article

C2 - 2994691

VL - 366

SP - 671

EP - 678

JO - Biological Chemistry

JF - Biological Chemistry

SN - 1431-6730

IS - 2

ER -