High secretory activity in the pancreatic B cells of a diabetic strain of the Japanese mouse

Zusammenfassung Elektronenmikroskopische Untersuchung von B-Zellen der Pankreas eines diabetischen Stammes japanischer Mäuse erbrachte den Hinweis gesteigerter Insulin-Synthese, bzw. gesteigerten Insulin-Ausflusses.     

Travel at low energetic cost by swimming and wave-riding bottlenose dolphins.

Over the past 50 years there has been much speculation about the energetic cost of swimming and wave-riding by dolphins. When aligned properly in front of the bow of moving ships in the stern wake of small boats, on wind waves, and even in the wake of larger cetaceans, the animals appear to move effortlessly through the water without the benefit of propulsive strokes by the flukes. Theoretically, body streamlining as well as other anatomical and behavioural adaptations contribute to low transport costs in these animals. The economy of movement permitted by wave-riding has been perceived as an energetic advantage for the swimming dolphin, but has been hard to prove in the absence of physiological data for exercising cetaceans. Here we determine the aerobic and anaerobic costs of swimming and wave-riding in bottlenose dolphins and find that the minimum cost of transport for swimming dolphins is 1.29 +/- 0.05 J kg-1 m-1 at a cruising speed of 2.1 m s-1. Aerobic costs are nearly twice as high for swimming seals and sea lions, and 8-12 times higher for human swimmers. Wave-riding by dolphins provides additional benefits in terms of speed. The results indicate that behavioural, physiological and morphological factors make swimming an economical form of high-speed travel for dolphins.     

Ultrastructural aspects of the pancreatic islets in carps of spontaneous diabetes mellitus

Zusammenfassung Elektronenmikroskopisch konnten in den Langerhansschen Inseln im Pankreas von normalen und diabetischen Fischen bestimmte Typen von Drüsenzellen differenziert werden, nämlich A-, B- und D-Zellen sowie klare Zellen. Bei diabetischen Fischen ist vor allem die sehr starke Vermehrung sogenannter klarer Zellen typisch.     

新型植物生长调节物质-Lepidimoide的生理作用及其与其它植物激素生理作用的比较

以燕麦、萝卜和水稻幼苗为材料，分析Lepidimoide的生理作用，并与其它激素的生理作用进行比较．研究结果表明：1Lepidimoide促进燕麦胚芽鞘切段的伸长，单侧处理燕麦胚芽鞘能产生弯曲生长，但作用效果略低于生长素；2Lepidimoide处理萝卜子叶能使叶绿素含量增加，但效果略低于BA，混合使用时作用效果高于单独使用BA或Lepidimoide；3Lepidimoide能促进水稻幼苗伸长，效果与GA3相似，但低浓度时效果不佳，混合使用时有一定的增效作用．上述结果表明，Lepidimoide是一种促进型生长调节物质，其作用与BA和GA3相似．     

Identification of nesfatin-1 as a satiety molecule in the hypothalamus

The brain hypothalamus contains certain secreted molecules that are important in regulating feeding behaviour. Here we show that nesfatin, corresponding to NEFA/nucleobindin2 (NUCB2), a secreted protein of unknown function, is expressed in the appetite-control hypothalamic nuclei in rats. Intracerebroventricular (i.c.v.) injection of NUCB2 reduces feeding. Rat cerebrospinal fluid contains nesfatin-1, an amino-terminal fragment derived from NUCB2, and its expression is decreased in the hypothalamic paraventricular nucleus under starved conditions. I.c.v. injection of nesfatin-1 decreases food intake in a dose-dependent manner, whereas injection of an antibody neutralizing nesfatin-1 stimulates appetite. In contrast, i.c.v. injection of other possible fragments processed from NUCB2 does not promote satiety, and conversion of NUCB2 to nesfatin-1 is necessary to induce feeding suppression. Chronic i.c.v. injection of nesfatin-1 reduces body weight, whereas rats gain body weight after chronic i.c.v. injection of antisense morpholino oligonucleotide against the gene encoding NUCB2. Nesfatin-1-induced anorexia occurs in Zucker rats with a leptin receptor mutation, and an anti-nesfatin-1 antibody does not block leptin-induced anorexia. In contrast, central injection of alpha-melanocyte-stimulating hormone elevates NUCB2 gene expression in the paraventricular nucleus, and satiety by nesfatin-1 is abolished by an antagonist of the melanocortin-3/4 receptor. We identify nesfatin-1 as a satiety molecule that is associated with melanocortin signalling in the hypothalamus.     

Expulsion of the placenta from the uterus is the principal initiator for collagen degradation in mouse uterus

In unilaterally pregnant mice, collagen degradation in the non-pregnant uterine horn was not initiated by removal of the fetus only but by removal of both the fetus and placenta. The results indicate that expulsion of the placenta from the uterus is a principal factor in the initiation of the process of collagen degradation simultaneously in the whole uterus.     

D-aspartate oxidase activity and D-aspartate content in a mutant mouse strain lacking D-amino acid oxidase

A mutant mouse strain ddY/DAO- lacks D-amino acid oxidase activity and accumulates free neutral D-amino acids in its tissues. In this study, D-aspartate oxidase activity and D-aspartate content in the tissues of these mutant mice were compared with those of normal mice. No significant difference was observed, indicating that the metabolism of acidic D-amino acids was unaffected in the mutant.