E. W. Busch

Trennung von basen, nucleosiden und nucleotiden auf kationenaustauschern

Abstract The separation of bases, nucleosides and nucleotides on cation exchangers The separation and determination of bases and nucleosides on cation exchangers using ammonium formate buffers were studied systematically and the results have been summarised in diagrams. Further possibilities of separation with water and diluted HCl are described. All methods were used in routine work. The separation of nucleotides (only pure substances) on cation exchangers is also described.

Abbauwege und Abbaumuster der Purinnucleotide in Herz-, Leber-, und Nierengewebe von Kaninchen nach Kreislaufstillstand

Abstract 1. 1. The metabolite concentrations during bloodstop are connected with the enzymes activities in cell compartments. From these facts we are able to conclude about the breakdown pathway and the special rate limiting reactions and we can explain the estimated levels of metabolites. 2. 2. The main pathway of the breakdown of purinenucleotides in kidney, liver and heart tissues proceeds via AMP, inosine, hypoxanthine to xanthine and to uric acid in the liver. The way via AMP to IMP and to inosine, as described by Deuticke 13, has to be a bypath. The first limiting step in the purine catabolism is the enzyme 5′-nucleotidase. In liver and kidney the second limiting step represents the xanthine oxydase. From these facts the typical breakdown pattern results for kidney and liver tissues with very high AMP levels in the beginning and after a long-time bloodstop with high amount of hypoxanthine. All the other metabolite concentrations are very low, except the xanthine level in liver tissue. 3. 3. A special case in kidney is the breakdown of guanosine nucleotides. The tissue is lacking of desaminizing enzymes for guanosine or guanine. Therefore guanine is accumulated in contrast to other tissues. After long-time experiments two thirds of the broken down RNA appears in the sum of purine metabolites of kidney tissues. 4. 4. Liver differs from kidney and the other tissues in the oxydative breakdown of hypoxanthine to xanthine and uric acid. The guanosine nucleotides are broken down to xanthine or xanthosine; guanine and guanosine themselves could not be estimated anymore. 5. 5. Another breakdown pattern we can see in heart tissue. AMP and inosine accumulate. During the whole experiment the concentration of inosine is 3 times higher than that of hypoxanthine. 6. 6. The analyses were performed by ion exchangers in a new manner.

Erfahrungen mit einem Enzymimmunoassay für Digoxin

Ein neuer Enzymimmunoassay für Digoxin * nach dem Prinzip der solid phase Technik wurde eingehend auf Präzision, Richtigkeit und Spezifität geprüft. Die Variationskoeffizienten der Präzision in der Serie und von Tag zu Tag entsprachen den Werten von Radioimmunoassays und lagen zwischen 4 und 15%; die Wiederfindung in Kontrollseren lag zwischen 87% im niedrigsten und 101% im höchsten Konzentrationsbereich. ß-Methyl-, und ß-Acetyl-Digoxin sowie Digoxigeninmonobzw. -bis-Digitoxosid werden im gleichen Maße wie Digoxin erfaßt. Digitoxin zeigte eine Kreuzreaktion von 33%. Spirono/acton sowie die beiden Metabolite Canrenon und Canrenoin-Säure ergaben Kreuzreaktionen von < ,01% und zeigten auch bei in vitro-Konzentrationen vom Zehnfachen der therapeutischen Sättigungsdosis keinen Einfluß auf den Test.