The effect of deoxycholate on microsomal adenosine triphosphatase prepared from the intestine of goldfish acclimatized to different temperatures

Riassunto L'attività di ATP-asi è stata studiata nella frazione dei microsomi preparata dalla mucosa intestinale del pesce dorato, acclimatato a 8° o 30°C. La differenza notata potrebbe essere una consequenza dell'alterazione nella struttura della membrana lipida plasmatica provocata per cambiamento della temperatura ambiente.

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Supported by a grant from Unilever Research Laboratories, Bedford, England.     

Electrical properties and glucose transfer in the goldfish intestine

Zusammenfassung Mitin vitro Dünndarmpräparat vom Goldfisch wird Glukose gegen ein Konzentrationsgefälle bei Temperaturen über 25°C transportiert. Es tritt eine temperaturabhängige elektrische Potentialdifferenz auf der Serosaseite positiv in Erscheinung. Bei Entfernung der Glukose verkleinerte sich die Potentialdifferenz um die Hälfte und verschwand völlig, wenn Ouabain der Serosaseite zugesetzt wurde. Die Befunde werden mit Experimenten an marinen Teleostiern verglichen.     

Knowledge transfer across scientific disciplines

Thomas Kuhn suggested that symbolic generalizations are applied to concrete systems by a process involving exemplars and analogical reasoning. Using the related concepts of theoretical and formal templates, I argue that the process of applying templates can in some cases be made explicit and that we do not need to rely on similarity relations and tacit knowledge. In so doing I show how some formal models can be transferred from one scientific field to another. Examples include scale-free networks, the Lotka-Volterra model from biology, and the Goodwin model in economics. I also argue that this explicit approach has advantages over the more psychologically oriented approach of Kuhn and explain the sense in which templates do and do not produce unification.     

The culture of goldfish cells (Carassius auratus) at high temperatures

Résumé Les cellules deCarassius auratus ont été cultivées in vitro avec succès à des températures allant jusqu'à 39 °C, les cellules du testicule en séries de 28 sous-cultures à 31.5 °C et 6 sous-cultures à 37.5 °C.     

Effect of different bathing media on the short-circuit current across the intestine of the rat and guinea-pig

Summary The changes in short-circuit current occurring when one or both solutions bathing the intestine of rat or guinea-pig mounted in flux chambers were recorded. The results with the guinea-pig can be explained in terms of diffusion potentials arising from the ionic replacements, and an electrogenic sodium pump, sensitive to ouabain, in the contraluminal membrane of the cell. In the rat, the situation is more complicated, and the enterocyte probably possesses an electrogenic sodium pump in the brush-border membrane.     

Effect of different bathing media on the short-circuit current across the intestine of the rat and guinea-pig.

The changes in short-circuit current occurring when one or both solutions bathing the intestine of rat or guinea-pig mounted in flux chambers were recorded. The results with the guinea-pig can be explained in terms of diffusion potentials arising from the ionic replacements, and an electrogenic sodium pump, sensitive to ouabain, in the contraluminal membrane of the cell. In the rat, the situation is more complicated, and the enterocyte probably possesses an electrogenic sodium pump in the brush-border membrane.     

Puromycin inhibition of changes in glucose-evoked potential recorded in goldfish intestine after periods of temperature acclimatization

Résumé Le potentiel transmural de l'intestin du poisson rouge, incubé in vitro, dépend partiellement de la présence de la glucose. Ce potentiel, dû à la glucose, est déterminé par la température d'acclimatation, et se réduit dans la mesure que cette température augmente. Cet aspect de l'acclimatation est complet 20 h après qu'on a élevé la température du milieu du poisson, et le puromycin entrave ces variations. Ces résultats suggèrent l'idée que les variations dans les propriétés des membranes de l'epithélium intestinal impliquent la synthèse des molécules de protéine.     

Sodium pumps and galactose transfer in the short-circuited small intestine

Summary In a short-circuited preparation of rat jejunum, there are two sodium pumps, one electrogenic and the other neutral. When energy sources are limited, the total sodium transfer is limited. In the presence of a non-metabolized actively transferred hexose, the electrogenic pump is preferentially used. The neutral sodium pump is only able to function when additional energy is available.     

Sodium pumps and galactose transfer in the short-circuited small intestine.

In a short-circuited preparation of rat jejunum, there are two sodium pumps, one electrogenic and the other neutral. When energy sources are limited, the total sodium transfer is limited. In the presence of a non-metabolized actively transferred hexose, the electrogenic pump is preferentially used. The neutral sodium pump is only able to function when additional energy is available.     

Crystal structure of barium titanium oxide at different temperatures

Résumé L'auteur a étudié aux rayons X la transition du titanate de barium autour de 120° C. Dans un intervalle de quelques degrés, il y a coexistence des deux formes cristallines (tétragonale et cubique). Il semble probable qu'il y a une nouvelle transition près de — 183° C. Il est intéressant de noter que ces points ne peuvent pas être attribués à une mise en rotation de molécules.     

Ventilatory responses to CO2 at different body temperatures in the snake,Coluber constrictor

Summary Ventilatory responses to CO₂ were examined at different temperatures in the snake,Coluber constrictor. CO₂ sensitivity increased between 15 and 25°C but not between 25 and 35°C. A rapidly occurring off-CO₂ transient hyperpnea suggested the presence of an intrapulmonary chemoreceptor.     

Acid phosphatase activity of small intestine of mice after exposure to different doses of gamma rays

Summary Effect of whole-body radiation at 3 different dose levels on the activity of acid phosphatase was studied in the small intestine of Swiss albino mice. In all the 3 exposure groups the enzyme activity increased significantly at 24 h after irradiation; the time at which the maximum histological damage was seen. With the beginning of recovery the enzyme tended to decrease and gradually approached control values.     

In situ Feulgen reaction with Schiff reagent at different temperatures

Zusammenfassung Mit Feulgenfärbung wurden auf Rattenleber bei Temperaturen von 40 und 60 C die besten Färberesultate erzielt.