Thrombozytose und Eosinophilie bei adrenalektomierten Ratten nach einmaliger 5-Hydroxytryptamininjektion

Summary In adrenalectomized rats, the injection of a single high dose of 5-hydroxytryptamin results, as in intact animals previously reported, in a strong increase of the number of platelets in the peripheral blood. The number of eosinophils, instead of decreasing, also rises. The maxima of increase are not in temporal accordance.     

Die teratogene Wirkung von Äthylharnstoff und Nitrit bei Ratten

Summary Simultaneous peroral application of ethylurea and sodium nitrite to pregnant Sprague-Dawley rats, on the 9th and 10th days of gestation, causes embryotoxic and/or teratogenic effects. Each substance alone does not afflict the fetuses, whereas the combined addition to the food permits the formation of ethyl nitroso-urea in the digestive tract. The latter readily passes the placenta and develops the teratogenic effect. It is to be considered that teratogenic substances can occur from food constituents in the human organism also.     

Radiotelemetrische Körpertemperaturmessung bei Mäusen und Ratten

Summary A simple and inexpensive radiotelemetric method for measurement of body temperature of small laboratory animals is described, and an example of a pharmacological application is given.

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Mit Unterstützung durch einen Kredit vom Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

Dämpfung des Kältezitterns durch Pentobarbital und Pethidin bei Ratten

Summary In rats, shivering was induced by cooling. Shivering started at 36.6°C in unanaesthetized rats and at 36.0°C in animals with light pentobarbital anaesthesia (5 mg/kg i.V.). Pethidine (2 mg/kg) lowered the onset of shivering in unanaesthetized rats to 35.3 °C and in anaesthetized animals to 33.0°C. The results suggest that the effect of pethidine upon shivering is potentiated by pentobarbital.     

Totale Plasmaclearance von Na[51Cr-ÄDTA] und Inulin-14C bei Ratten

Summary Plasmaclearance and whole body retention of Na[⁵¹Cr-EDTA) and of inulin-¹⁴C have been determined in healthy rats. The total plasmaclearance of both compounds is identical and corresponds to the value of glomerular filtration rate in rats as determined under steady-state conditions.     

Die Mitosehäufigkeit in der normalen Epidermis der Maus nach einmaliger DMSO-Einwirkung

Summary 12 h after local application of DMSO on the epidermis of the mouse, increased mitotic activity has been observed, the maximum occurring 24 h after the onset of the experiment. Subsequently a distinct reduction of the frequency of mitosis can be seen with a minimum occurring about 53 h after the beginning of experiment. The initial mean value is reached 12 h after.     

Ursachen der geschlechtsunterschiedlichen MilchdrÜsengewebsentwickiung bei Ratten

Summary Under the same hormonal conditions, mammary gland growth in adult female rats is more pronounced than in males. Since there are no differences in the glandular development of both sexes, either at birth or at 30 days of life, it is assumed that male rats react less sensitively than female rats in response to a hormonal stimulus with regard to mammary gland growth. It is presumed that androgen influence during the differentiation stage is responsible for the fixation of a decreased sensitivity of the positive feedback-mechanism between estrogens and prolactin secretion in males. Thus changes in sensitivity would be the reason for mammary gland growth in males being smaller than in females under the same hormonal conditions.

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Dieser Arbeit liegen zum Teil die Untersuchungsergebnisse einer SchÜler-Facharbeit von U.Rieser zugrunde.     

Radiostrontium-Ausscheidung im Kot junger Ratten nach calciumreicher Ernährung

Summary Young immature rats of both sexes were fed with a diet either high (1.95%) or low (0.31%) in Ca content. A s.c. injection of weightless⁹⁰Sr results in a better excretion of radiostrontium with the faeces during feeding with high Ca diet. The retention of activity in the femori 30 days after injection is, in the same case, lower than by feeding with low Ca diet.     

Die Wirkung von intraventrikulär applizierteml-Glutamat auf die Akquisition und Extinktion einer instrumentellen Konditionierungsreaktion bei Ratten

Summary The effect of intraventriculary administeredl-glutamic acid upon a conditioned avoidance response was studied. The amino acid caused at first shorted reaction times and increased success quota, and later prolonged the reaction times and slowed success quota.     

Hemmwirkung von Cysteamin auf den Corticosterongehalt der Nebennieren von Ratten nach Stress-Einwirkung

Summary In rats, cysteamine has an inhibiting effect on the corticosterone increase in the adrenals and blood following stress. It is discussed whether cysteamine might interfere with the corticosteroide synthesis.     

Rotationssinn nach dem Bogengangsprinzip bei Crustaceen

Summary Blinded crabs (Carcinus maenas andMaja verrucosa) show compensatory eye stalk movements on rotation about a vertical axis, in water and in air. On a sudden arrest of the turntable typical after-effects are observed, which show a striking resemblance to those known from vertebrates. All these reactions are abolished after bilateral elimination of the so-called thread hairs within the statocysts (experiments onMaja). In fresh preparations these hairs can be seen to follow the slightest movements of the surrounding fluid, swaying around their point of attachment.Elimination of the thread hairs does not diminish, but does markedly delay the compensatory eye stalk movements of a blinded crab on rotation about horizontal axes. The latter reactions are abolished if in addition the hook hairs (i.e. the sense hairs of the statolith-bearing type) are destroyed.It is concluded that the statocyst of crabs is a staticdynamic sense organ: the hook hairs are position receptors, the thread hairs react to angular displacements about all three main body axes; the group hairs may have no sensory function at all.Rotation sense may be expected to occur in other Crustacea possessing thread hairs or similar receptors in their statocysts as well.     

Der Einfluss der Epiphyse auf die Lokomotionsaktivität bei Ratten

Summary After pinealectomy adult hypoactive rats show an increased exploratory behavior, whereas adult hyperactive rats show no significant behavioral change. These data are discussed in relation to brain serotonin content.

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Durchgeführt im Rahmen des DFG-Schwerpunktprogrammes Neuroendokrinologie (Vo 135/4).

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Frau Dr. D. Freund, Mainz, danke ich für die Erlaubnis zur Benutzung der Open-Field Anlage, Frau H. Untiedt für technische Hilfe bei der Pinealektomie.     

Histidindecarboxylaseaktivität in Samenblasen unreifer und testosteronbehandelter Ratten

Summary The seminal vesicles of immature rats which had been treated with testosterone showed a twofold (threefold) increase in growth, but did not show increased histamine formation after in vitro incubation withl-histidine-¹⁴C.     

Das Nebenhodengangepithel der Ratte nach Hypophysektomie und nach Androgensubstitution

Summary The epithelium of the epididymal duct (corpus region) of the rat after hypophysectomy and after androgen substitution has been examined by light and electron microscopy. The epithelium consists of 3 different cell types: principal, accessory (Nebenzellen), and basal cells. The characteristics of these cells disappear after hypophysectomy and redifferentiate after androgen application. The alterations of the principal and accessory cells in course of time (from the 1st week up to 9 weeks after injection of 20 mg testosterone propionate) are the subject of this report.     

Morphologische Veränderungen der Extraorbitaldrüsen weisser Ratten nach Kupfermangelernährung

Summary Copper deficiency of the rat leads to a reduction of the histochemically demonstrable cytochrome oxidase activity of the glandula extraorbitalis, and to atrophy and fatty degeneration of the glandular cells. The histological alterations are more pronounced in the male than in the female.     

Hemmung des durch blutdrucksenkende Pharmaka bei Ratten ausgelösten Trinkens durch Nephrektomie

Summary The drinking response of rats seen after the hypotensive drugs phentolamine, isoproterenol and hydralazine/bretylium can be abolished by nephrectomy. It is postulated, that the dipsogenic activity of these drugs is mediated by renin.     

Die Azetylcholinesterase an der motorischen Endplatte des Rattenzwerchfells nach Intoxikation mit Paraoxon und Soman bei Applikation von Oximen

Summary The inhibition of AChE by Paraoxon is overcome by the application of the oximes 2-PAM, Toxogonin^® and HS 3. Soman inhibited AChE is affected only to a limited extent by HS 3 and HS 9.     

Fluoreszenzmikroskopische Untersuchungen am Hypothalamus männlicher Ratten nach Behandlung mit einer antimaskulin wirkenden Substanz

Summary In new-born male rats daily injections of a strong antiandrogenic substance led to an increase of the catecholamine content in the parvicellular perikarya as well as in nerve fibres leading to the paraventricular and supraoptic nuclei. The same effect was observed in male rats castrated immediately after birth. A possible relationship between gonadotropic releasing factors and the catecholamin content of the hypothalamic nuclei is discussed.     

Der Kininogenspiegel von Ratten und Kaninchen während der Gestation

Summary The investigations concern the alterations of the plasma kininogen level of rats and rabbits during gestation. The results obtained with these animals are analogous to man. For this reason rats and rabbits are suitable models for further studies on the importance of the kininogen/kinin-system during pregnancy and delivery.