Desoxyribonucleasen und Phosphatasen der Rattenleber nach Cancerisierung durch Di�thylnitrosamin

Tempel, K.; Hollatz, R.

doi:10.1007/bf00304019

Cited by 7 publications

(1 citation statement)

References 9 publications

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“…Histochemical investigations suggest that a "deficiency of nucleases precedes or facilitates carcinogenesis" (3,4). In most cases, however, biochemical studies with homogenates of experimental tumours and/or tumour bearing organs revealed an increase of acid and/or a decrease of alkaline DNase activity (7,8,13). Less consistent results were obtained with spontaneous blastomas (5).…”

Section: Discussionmentioning

confidence: 95%

The Behaviour of Deoxyribonucleases of Rat Liver in the Course of Diethylnitrosamine- Induced Carcinogenesis

Tempel

Hollatz

2010

Zentralblatt Für Veterinärmedizin Reihe A

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Summary Diethylnitrosamine (DENA) was given to rats in the drinking water at a level of 0.003% for periods of 2–24 weeks. The ratio (Q) of DNase II (EC 3.1.4.6) — to DNase I (EC 3.1.4.5) — activities increased significantly and in an irreversible manner within the liver homogenates about 4 weeks after the onset of the experiment. 2–4 weeks later DNase I activity decreased by about 25–45 per cent. No distinct relationship existed between the activities of DNase I and DNase I‐inhibitor. Nuclear DNase II activity increased steadily during the development of liver cell carcinomas. Whereas no definite conclusions can be drawn as to the significance of DNases for carcinogenesis, nuclear DNase II activity may play an essential role in regulating DNA synthesis. Zusammenfassung Desoxyribonucleasen der Rattenleber während Cancerisierung durch Diäthylnitrosamin Chronische Diäthylnitrosamin (DENA)‐Gabe (Trinkwasserzusätze entsprechend Endkonzentrationen von 0,003%) führte bei Ratten binnen 4 Wochen zu einem signifikanten und irreversiblen Anstieg des Aktivitätsverhältnisses (Q) von DNase II (EC 3.1.4.6) und DNase I (EC 3.1.4.5) der Leberhomogenate. 2–4 Wochen später verminderte sich die DNase I‐Aktivität um 25–45%. Zwischen den Aktivitäten von DNase I und DNase I‐Hemmstoff ergab sich keine verwertbare Korrelation. Die Aktivität einer Zellkern‐DNase II war erstmals 14 Wochen nach Versuchsbeginn signifikant erhöht. Sie vergrößerte sich anschließend bis zum Vierfachen der Norm. — Die Ergebnisse unterstreichen die Bedeutung einer nukleären DNase II für die Regulation der DNA‐Synthese. Die Funktion von DNasen im Mechanismus der Carcinogenese bleibt Gegenstand weiterer Untersuchungen. Résumé Désoxyribonucléases dans le foie de rats lors d'une carcinogenèse induite par la diéthylnitrosamine L'administration chronique de diéthylnitrosamine (DENA) dans l'eau de boisson à une concentration finale de 0,003% provoqua en 4 semaines chez des rats une augmentation significative et irréversible des rapports d'activité (Q) de DNase II (EC 3.1.4.6) et DNase I (EC 3.1.4.5) des homogénats hépatiques. L'activité de DNase I diminua de 25–45% 2–4 semaines plus tard. Il n'y a pas eu de corrélation utilisable entre DNase I et l'inhibiteur DNase I. L'activité d'une DNase II d'un noyau cellulaire n'augmenta de façon significative que 14 semaines après le début de la recherche. Elle augmenta finalement de 4 fois la valeur normale. Les résultats soulignent la signification d'une DNase II nucléaire pour la régulation de la synthèse de l'ADN. La fonction des DNases dans le mécanisme de la carcinogenèse reste l'objet de nouvelles recherches. Resumen Las desoxirribonucleasas hepáticas de rata durante la carcinogenia inducida por dietilnitrosamina La administración crónica de dietilnitrosamina (DENA), en forma de adiciones al agua de bebida correspondiendo a la concentración final de 0,003%, conducía en ratas en el plazo de 4 semanas a un aumento significante e irreversible de la relación de actividad (Q) de DNasa II (EC 3.1.4.6) y DNasa I (EC 3.1.4.5) de lo...

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Section: Discussionmentioning

confidence: 95%

The Behaviour of Deoxyribonucleases of Rat Liver in the Course of Diethylnitrosamine- Induced Carcinogenesis

Tempel

Hollatz

2010

Zentralblatt Für Veterinärmedizin Reihe A

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Die Cytologie der Hepatocarcinogenese

Bannasch¹

1975

Geschwülste · Tumors III

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Histochemical correlation between glycogen, nucleic acids and nucleases in pre-neoplastic and neoplastic lesions of rat liver after short-term administration of N-nitrosomorpholine

Taper

Bannasch

1976

Z. Krebsforsch.

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After 7 weeks of oral administration of the carcinogen N-nitrosomorpholine (12 mg NNM ad 100 ml of drinking water) to male rats, marked hepatocellular changes were found predominantly in the centers of the lobules. These were loss of glycogen, disorganisation of the basophilic bodies and, sometimes, loss of cytoplasmic basophilia or pyroninophilia, necrotic cells and increase in the activity of acid DNAse and RNAse. These centrilobular alterations were reversible after withdrawal of the carcinogen. They are, therefore, attributed to the nonspecific-toxic effect of the carcinogen. In peripheral and midzonal regions of the lobules basically different cellular changes appeared which were unimportant during the phase of intoxication, but became prominent after cessation of the carcinogenic treatment. These lesions were: excessive storage of glycogen, displacement of basophilic bodies and an increase in cytoplasmic acidophilia. The hepatocytes showing these cytoplasmic changes initially formed foci. Neoplastic nodules and frank hepatocellular carcinomas developed later. During these later stages of the experiment both the foci and the nodules consisted of 4 main types of altered hepatocytes: 1) "clear" glycogen storage cells, 2) acidophilic cells, 3) vacuolated (fat storing) cells, 4) basophilic (pyroninophilic) cells poor in, or free from, glycogen. The larger nodules and carcinomas contained predominantly basophilic cells. The activity of nucleases, especially that of acid DNAse, decreased in small foci which as a rule developed later than the foci of glycogen storage. In most cells of neoplastic nodules and carcinomas the activity of these enzymes disappeared, but it reappeared in necrotic cells. The progressive alterations in the activity of the nucleases seemed to be related to the phenotypic expression of malignancy and could be a sign of a fundamental metabolic change taking place during a relatively late step in the malignant transformation.

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Desoxyribonucleasen und Phosphatasen der Rattenleber nach Cancerisierung durch Di�thylnitrosamin

Cited by 7 publications

References 9 publications

The Behaviour of Deoxyribonucleases of Rat Liver in the Course of Diethylnitrosamine- Induced Carcinogenesis

The Behaviour of Deoxyribonucleases of Rat Liver in the Course of Diethylnitrosamine- Induced Carcinogenesis

Die Cytologie der Hepatocarcinogenese

Histochemical correlation between glycogen, nucleic acids and nucleases in pre-neoplastic and neoplastic lesions of rat liver after short-term administration of N-nitrosomorpholine

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