[Morphometric studies of the proximal tubules of the rat kidney considering the effect of the method of killing]. / Morphometrische Untersuchungen am proximalen Tubulus der Rattenniere unter dem Einfluss der Tötungsart.

120 male rats belonging to two different strains (Han: WIST, Han: SPRD) and two different weight groups (group I: lighter body weight, group II heavier body weight) were killed on three different methods (decapitation, Nembutal -overdose greater than 250 mg/kg b.w. i.p. less than, exsanguination in Nembutal -anaesthesia greater than 100 mg/kg b.w. i.p.). Subsequently, changes in tubuli contorti I of the left kidneys were examined morphometrically. The mean total area, luminal area and epithelial area were evaluated as well as the mean diameter of the tubular nuclei. Concerning the areas of the proximal tubules only the luminal areas show differences between the Wistar and the Sprague-Dawley strain. The total, luminal and epithelial area in the rats belonging to the weight group II were significantly larger than in the rats belonging to weight group I. With one exception this could be noticed within both strains and all three modes of killing. In both strains and weight groups the rats were killed by Nembutal -overdose or exsanguination showed significantly smaller total, luminal and epithelial areas than the rats that were decapitated. Possible cause heretofore are discussed. Differences between the tubular areas of the rats that were killed by Nembutal -overdose and those that were killed by exsanguination after Nembutal -anaesthesia could not be established. The measurements of nuclei diameters in the proximal tubules did not lead to clearly different results between both strains, weight groups and the various modes of killing.

[Animal welfare relevance and the functional and morphological significance of the killing of laboratory animals]. / Tierschutzrelevanz sowie funktionelle und morphologische Bedeutung der Tötung von Versuchstieren.

Euthanasia of experimental animals at the end of an experiment or when an experiment is terminated is relevant for two reasons: firstly, because of ethical reasons and of animal protection, secondly because of scientific evaluation of experimental results. Functional and morphologic alterations have up to now been inadequately observed and considered. Gradually varying different results depend on the different methods of euthanasia. Additionally single parameters of reactions in isolated organs vary depending on the method of euthanasia. These facts have not yet been respected in the discussion of so called alternate methods. The significance of functional and morphologic effects as seen in different methods of euthanasia is discussed with examples.

[Pharmacology and toxicology of etofylline clofibrate]. / Zur Pharmakologie und Toxikologie von Etofyllinclofibrat.

1-(Theophyllin-7-yl)-ethyl-2-[2-(p-chlorophenoxy)-2-methylpropionate] (etofylline clofibrate, ML 1024, Duolip) was investigated in acute and chronic toxicity studies, using oral application. In addition studies in reproduction toxicology and safety pharmacology were performed. Under the conditions of the experiments the following important findings were observed: In the acute toxicity studies ML 1024 showed a dose-dependent symptomatology in all three species (rat, mouse, dog) used, no late mortalities occurred. As compared to the reference substances clofibric acid, clofibrate and etofylline, ML 1024 showed a considerably lower toxicity. The chronic studies over 6 months in mini-pigs and rats revealed that the liver was the target organ in both species. ML 1024 influenced the reproduction performance of the male and female rat. However, toxic dose levels were necessary to achieve those effects. In the teratogenic studies no teratogenic but some fetotoxic effects in the high dose level were observed. No effects could be observed in the peri- and postnatal experiment. The pharmacodynamic studies did not reveal any significant functional influences of ML 1024 on the major organs and organ systems.