R. Lesch

Experimental hepatitis induced by d-galactosamine

Abstract Repeated intraperitoneal injections of d -galactosamine produce within 24–48 hours in rat livers alterations that closely resemble human viral hepatitis. Histologic changes include necroses and inflammatory infiltration of periportal areas, mitoses and cell proliferation, the appearance of Councilman bodies, and an increased number of Kupffer cells. Serum levels of transaminases, glutamate-dehydrogenase, and other enzymes are greatly increased while total serum protein, including prothrombin, is reduced. No fatty infiltration of the liver occurs. Liver glycogen is rapidly depleted after galactosamine administration. The levels of several metabolites in liver, including adenine nucleotides and UDP-glucose, are significantly reduced. The ATP ADP- and lactate/pyruvate ratios remain in the normal range. These effects of galactosamine are dose dependent and can also be produced in other animals, though differences in quantitative response seem to exist. Several other chemically related compounds do not produce similar effects indicating a high specificity of d -galactosamine. Galactosamine hepatitis may serve as a biochemical and pathologic model.

Liver restitution after acute galactosamine hepatitis: autoradiographic and biochemical studies in rats.

Abstract Autoradiographic and biochemical studies were performed to elucidate the restitution of rat liver after galactosamine hepatitis. The maxima of proliferation of Kupffer cells were seen after 25.5 hours, of periportal mesenchymal cells and of bile duct epithelia after 48 hours, and of hepatocytes after 72 hours, when galactosamine was given six times within 24 hours. A single injection produced a corresponding labelling pattern of the different liver cell types. The normalization of serum enzyme levels (GOT, SDH) and of the liver glycogen store was paralleled to the histologic signs of regeneration.

Hepatotoxicity of d-Galactosamine in the isolated perfused rat liver

Abstract The hepatotoxicty of d -galactosamine was evaluated using the isolated perfused rat liver. In controls, ATP- and UDPglucose-levels decreased by about 20% during 12 hr of perfusions; UTP + UDP as well as the energy charge remained constant. d -Galactosamine reduced the contents of UDPglucose and UTP + UDP to 10 to 20% of normal within 30 min, whereas the sum of all acid-soluble uracil nucleotides increased linearly for the first 8 hr. The leakage of intracellular enzymes into the perfusion medium was small and almost linear in controls; in livers treated with d -galactosamine, however, a sharp increase occurred after 6 hr. Addition of uridine 3 hr after d -galactosamine prevented cell damage as judged by enzyme release. E. coli endotoxin, either alone or after preincubation with rat serum, did not enhance enzyme leakage. Lightmicroscopically, liver cell plates were partially dissociated and necroses of groups of liver cells were found in galactosamine-treated livers. In electron microscopy, degenerative changes of hepatocytes were seen after galactosamine perfusion.

Über die primäre und sekundäre biochemische Antwort der Leber nach Gabe von D-Galaktosamin beim Zustandekommen der Galaktosaminhepatitis

Durch die Gabe von D-Galaktosamin (GalN) wird innerhalb von ≤ 6 Std in Ratten ein Hepatitis erzeugt [1, 2, 3, 20]. Um die schadigende Wirkung von GalN auf die Struktur und Funktion der Leberzelle zu untersuchen, hat es sich als nutzlich erwiesen, zwischen einer primaren (I) und sekundaren biochemischen Antwort der Leber (II) nach GalN-Gabe zu unterscheiden [4, 5]. „Antwort“ soll dem Begriff „Lasion“ vorgezogen werden, wie er von Peters [6] fur die Pathobiochemie des Thiaminmangels, z. B., eingefuhrt wurde, da im Falle des Galaktosaminschadens nicht alle unter I und II auftretenden Veranderungen zu einer Schadigung der Leber zu fuhren brauchen [4].

The development of cholangiofibrosis and hepatomas in galactosamine induced cirrhotic rat livers

SummaryDaily injection of GalN leads to the development of cholangiofibrosis and hepatomas in rat liver. This development depends on the metabolization of GalN to GalN-1-P, UDP-hexosamines, N-acetyl-hexosamine-P, and UDP-N-acetyl-hexosamines.

Aktivitätsverhalten lysosomaler proteinabbauender Enzyme der Rattenleber bei der Galaktosamin-Hepatitis: Kathepsin D, Kathepsin A und saure Carboxypeptidase

SummaryChanges of activity and distribution in rat liver of the lysosomal enzymes cathepsin D, cathepsin A, and acid carboxypeptidase are described as a result of D-galactosamine action. Hepatitis was provoked by acute and by prolonged administration of D-galactosamine. A lysosomal pellet and a lysosomal supernatant fraction were prepared from rat liver by centrifugation according to de Duve. Total activity of the respective enzymes mentioned above was assayed in the liver homogenate. A loss of enzyme activities in the lysosomal pellet and an increase in the supernatant fraction was observed after 25 hours in acute hepatitis following D-galactosamine administration. Total activities of cathepsin D and acid carboxypeptidase per gram liver wet weight were significantly decreased. Administration of D-galactosamine over 8 days resulted in a significant increase of the three enzyme activities in the lysosomal supernatant fraction; as compared to the acute hepatitis, however, this increase was less marked. Total activities of cathepsin D and A per gram liver wet weight increased during prolonged D-galactosamine administration; this is interpreted as a result of liver regeneration.D-Galactosamine action in liver leads to more labile lysosomes.ZusammenfassungIn der vorliegenden Arbeit wird über das Verhalten der lysosomalen Enzyme Kathepsin D, Kathepsin A und saure Carboxypeptidase bei einer akut und einer subakut verlaufenden Galaktosamin-Hepatitis der Ratte berichtet. Es werden Rattenlebern nach der Methode von de Duve durch Zentrifugation in ein Lysosomen-Sediment und einen Lysosomen-Überstand fraktioniert. Ein Teil der Leber wird zur Bestimmung der Gesamtaktivität der oben genannten Enzyme homogenisiert. Bei der akuten Hepatitis nehmen nach 25 Std die Enzymaktivitäten in der Lysosomen-Sediment-Fraktion ab, in der Lysosomen-Überstands-Fraktion zu. Die Aktivität dieser Enzyme pro g Leberfrischgewicht nimmt bis auf die von Kathepsin A signifikant ab. Bei der subakuten Galaktosamin-Hepatitis ist nach 8 Tagen ein signifikanter Anstieg der 3 Enzymaktivitäten in der Lysosomen-Überstandsfraktion nachweisbar; er ist im Vergleich zur akuten Schädigung weniger ausgeprägt. Die Aktivitäten von Kathepsin D und A pro g Leberfrischgewicht nehmen zu; diese Zunahme im Verlauf der subakuten Hepatitis könnte Ausdruck einer Regenerationsleistung der Leber sein.Unter der Wirkung von Galaktosamin werden die Lysosomen instabiler.

Entwicklung einer experimentellen Lebercirrhose durch D-Galaktosamin

SummaryIntraperitoneal injections of D-galactosamine. HC1 in rats produce chronic progressive hepatitis that leads within six months to cirrhosis. The pathological process starts with focal necroses of parenchyma and periportal proliferation of mesenchymal cells and bile ducts. During this initial phase the serum enzyme activities are not considerably elevated. In the stage of cirrhosis the parenchymal alterations are less pronounced while autoradiographic analysis after administration of thymidine-3H shows an increasing proliferation of mesenchymal cells. In contrast to the increased regenerative proliferation of the epithelial cells in the precirrhotic stage, a different intensity of proliferation is observed in parenchymal nodules. That indicates a focal alteration of tissue differentiation. After galactosamine administration for 6 months the liver glycogen and glucose contents are reduced significantly, whereas the ATP1 level is normal. The changes in concentrations of uridine phosphates (UTP, UDP, UMP), UDP-sugars, and of galactosamine metabolites show an adaptation of uracil nucleotide and galactosamine metabolism in chronically galactosamine treated rat liver. The immune suppressive compound Azathioprin does not influence the development of liver cirrhosis.ZusammenfassungDurch intraperitoneale Injektionen von D-Galaktosamin HC1 wird bei Ratten innerhalb von 6 Monaten über das Stadium der chronisch fortschreitenden Hepatitis eine Lebercirrhose erzeugt. Dieser Prozess beginnt mit einer Leberparenchymschädigung und periportaler Mesenchymzell- und Gallengangswucherung. In diesem Zeitraum sind die gemessenen Serumenzymaktivitäten nicht wesentlich erhöht. Im Stadium des cirrhotischen Umbaus stehen die Veränderungen am Parenchym im Hintergrund, während autoradiographisch eine zunehmende Mesenchymzellproliferation zu beobachten ist. Im Gegensatz zur regenerativen Steigerung der Epithelproliferation im präcirrhotischen Stadium weist die unterschiedlich starke Proliferation in den insularen Regeneraten auf eine herdförmige Änderung der Gewebsdifferenzierung hin. Der Glykogen- und Glucosegehalt der Leber ist nach 6monatiger Galaktosaminbehandlung signifikant vermindert, der ATP-Spiegel jedoch normal. Die Veränderungen der Konzentrationen der Uridinphosphate (UTP, UDP, UMP), der UDP-Zucker und von Metaboliten des Galaktosamins zeigen eine Anpassung des Uracilnukleotid- und Galaktosaminstoffwechseis an das langdauernde Galaktosaminangebot. Versuche mit der immunsuppressiven Substanz Azathioprin zeigten keinen Einfluß auf die Entwicklung der Lebercirrhose.

Investigations on D-Galactosamine Hepatitis after Pretreatment with alpha-Hexachlorocyclohexane

D-Galactosamine hepatitis cannot be induced in rapidly replicating liver tissue at various times after induction of proliferation. Proliferation was induced by administration of alpha-hexachlorocyclohexane. The morphological features of galactosamine hepatitis do not appear or are very mild. The onset of DNA synthesis is delayed to about 12 hrs as also shown in partially hepatectomized rats.

Das Verhalten lysosomaler proteinabbauender Enzyme bei Erkrankungen der menschlichen Leber

Summary121 liver biospies were classified according to the histological picture. Protein, cathepsin D, acid carboxy-peptidase and—provided enough material was available—DNA were determined in samples obtained by needle biopsy and surgical excision. A correlation exists between the severity of the histological and laboratory findings and the elevation of the protein degrading lysosomal enzymes. To explain the relatively high increase of hepatozytic enzyme content in extrahepatic cholestasis, a mechanical defect of lysosomal enzyme excretion into the bile ducts is discussed. In two cases of carcinoma of the stomach an elevation of the cathepsin D and acid carboxypeptidase activities was found in spite of the absence of liver disease. It is supposed that this enhancement is the result of an elevated protein turnover.Zusammenfassung121 Leberproben wurden nach histologischen Kriterien verschiedenen Lebererkrankungen zugeordnet. In Biopsie-, bzw. Excisionsmaterial wurde Protein, Kathepsin D, saure Carboxypeptidase und, soweit noch genügend Homogenat vorhanden war, Desoxyribonucleinsäure gemessen. Es bestand eine Korrelation zwischen Zunahme des histologisch und klinisch chemisch nachgewiesenen Leberzellschadens und Aktivitätsanstieg der beiden lysosomalen proteinabbauenden Enzyme. Für den relativ hohen Enzymgehalt der Leberzellen bei der extrahepatischen Cholestase wurde als einer der möglichen ursächlichen Faktoren die mechanische Behinderung der Ausscheidung lysosomaler Enzyme über die Gallenwege diskutiert. Zwei Fälle mit Magen-Karzinomen wiesen bei morphologisch unauffälligem Leberbefund hohe Aktivitäten an Kathepsin D und saurer Carboxypeptidase auf. Es wird vermutet, daß dieser Anstieg Ausdruck des gesteigerten Proteinumsatzes ist.

Induction of edema in the adrenalectomized rat by D-galactosamine.

A single dose of o-galactosamine (GalN) given to rats over 4 weeks of age induces a hepatitis closely resembling human viral hepatitis [1, 2, 3]; however, the regenerating rat liver is refractory to GaIN during the phase of high mitotic activity and enhanced growth rate [4, 5, 6] .--One to three days after adrenalectomy (AE), the rat liver shows high mitotic activity without enhanced stimulation of growth [7, 8], apparently providing another experimental model for testing this characteristic of DNA replicating liver [4, 5, 6]. In addition, these studies demonstrate a previously unreported effect of GaIN action: the induction of edema in the adrenalectomized rat. Group A animals received a single dose of 375mg GaiN-HC1/kg i.p. at different times after AE (GAIN from C. Roth, OHG, Karlsruhe, Germany) ; they were killed 12hours later; group B animals received no GalN after AE; groNp C animals were sham operated and received 375 mg GaIN 9 HCI/kg i.p. 36 h after AE (table).--A striking feature