Na-Activated calcium efflux in rabbit vagus nerve fibres

Zusammenfassung Die vorliegenden Resultate deuten darauf hin, dass aus marklosen Nervenfasern ein passiver Austausch von intrazellulärem Kalzium gegen extrazelluläres Natrium erfolgt, und zwar mittels eines überträgersystems, das von dem für die Erregung notwendigen Na-übertragenden System verschieden ist.     

The production of plasminogen activator during perfusion of isolated rabbit kidneys

Résumé On a constaté que la production et la sécrétion de l'activateur du plasminogéne a lieu pendant la perfusion des reins du lapin à l'aide d'une suspension d'érythrocytes oxygenés.     

Influence of hypoxia on contractility and calcium uptake in rabbit aorta

Summary The influence of hypoxia on noradrenaline (NA)-induced contractions and⁴⁵Ca uptake has been studied on isolated rabbit aortae. Hypoxia significantly decreased the contractility of aortic strips. NA stimulation resulted in increased or decreased⁴⁵Ca uptake by normoxic or hypoxic specimens, respectively. Relating⁴⁵Ca movement with mechanical activity, the results suggest that decrease in Ca⁺⁺ uptake may be mechanism for hypoxic relaxation of aortic smooth muscle.The author acknowledges facilities at the Wellcome Surgical Research Institute, University of Glasgow, U.K. Much of this work was in collaboration with Drs Sheila Jennett and J.D. Pickard.     

Algal single cell protein production from sewage effluent with high salinity

Summary Laboratory studies indicate that the unicellular green algaChlorella salina CU-1 could be cultivated in treated sewage effluent with high salinity. The high protein content (51% dry weight), and the relatively complete amino acid profile of the cells, suggest that this alga might be an ideal organism to be used for single cell protein production from high-salinity sewage.     

Formation of norepinephrine from tyrosine in isolated rabbit heart

Zusammenfassung Die Bildung des Noradrenalins aus Tyrosin konnte im isolierten Kaninchenherzen nachgewiesen werden. Die Reaktion scheint für Tyrosin spezifisch zu sein. Aus Tyramin wurde kein Noradrenalin gebildet. Ebenfalls wurde die Umwandlung von Tyramin in Norsynephrin und von Dopamin in Noradrenalin nachgewiesen.     

Active transport in the rabbit blastocyst

Résumé Des blastokystes ont été pris à des lapins 6 jours après l'accouplement et couvés in vitro pendant 7 h. Le transport d'eau et de chlorure de soude a été arrêté par l'ouabaine ou par refroidissement. L'acétazolamide met en équillibre les concentrations de bicarbonate-chlorure. Il nous semble donc que c'est le transport de l'ATPase qui extrait le chlorure de soude et que l'anhydrase carbonique y concourt maintenant une concentration elevée de bicarbonate à l'intérieur du blastokyste.     

Role of calcium in the histamine release induced by D-galactosamine from rat mast cells

Rat peritoneal mast cells were isolated and purified by differential centrifugation in Ficoll. Cells pooled from three to four rats were suspended at approximately 10(6) cells/ml in a buffered salt solution and incubated for 1 h at 37 degrees C in 300 microliter volumes in the absence or presence (9 X 10(-4) M) of calcium chloride. Addition of D-galactosamine hydrochloride (DGM; 2.8 X 10(-4)M) caused (in addition to basal release) a mean +/- SEM percent histamine release of 15.7 +/- 5.2 in the presence of Ca++ and 19 +/- 4.9 in the absence of Ca++ (p greater than 0.05). It is suggested that D-galactosamine does not require extracellular Ca++ for the release of histamine from the rat mast cell.     

Role of calcium in the histamine release induced by D-galactosamine from rat mast cells

Summary Rat peritoneal mast cells were isolated and purified by differential centrifugation in Ficoll. Cells pooled from three to four rats were suspended at approximately 10⁶ cells/ml in a buffered salt solution and incubated for 1 h at 37°C in 300 l volumes in the absence or presence (9×10^–4 M) of calcium chloride. Addition of D-galactosamine hydrochloride (DGM; 2.8×10^–4 M) caused (in addition to basal release) a mean ±SEM percent histamine release of 15.7±5.2 in the presence of Ca⁺⁺ and 19±4.9 in the absence of Ca⁺⁺ (p>0.05). It is suggested that D-galactosamine does not require extracellular Ca⁺⁺ for the release of histamine from the rat mast cell.A preliminary analysis of these results was presented at the International Symposium on calcium entry blockers and tissue protection, Rome, 15–16 March 1984.     

Isolation of highly purified glomerular complexes from rabbit cerebellum

Zusammenfassung Es wird eine neue Methode zur Präparation der sogenannten «glomerulären Komplexe» aus Kaninchen-Kleinhirn beschrieben, deren komplexe innere Struktur weitgehend intakt bleibt. Mit Hilfe der quantitativen elektronenmikroskopischen Methode wurden über 90% intakter Glomeruli errechnet.     

Optically aimed ear movements in the rabbit

Zusammenfassung Durch Bewegungssehen ausgelöste Ohrmuschelbewegungen beim Kaninchen werden registriert. Die Ohrmuscheln werden dem Objekt zugewendet. Umgekehrt wie beim Menschen, wo akustische Reize eine gerichtete Blickwendung auszulösen vermögen, erfolgt hier auf visuellen Reiz hin eine gerichtete Ohrmuschelwendung.     

Response of serum calcium to administration of an extract from Stannius corpuscles in the anurans

Summary The effect of i.p. injection of an aqueous extract of Stannius corpuscles (10 mg/ml/100 g b.wt) on serum calcium levels was investigated inRana cyanophlyctis andBufo andersonii. This treatment evokes in both species hypocalcemia over a period of 1–4 h, followed by hypercalcemia at 6 h, with a return to control at 8 h.     

Sulfhydryl oxidation induces calcium release from fragmented sarcoplasmic reticulum even in the presence of glutathione

Alcian blue and plumbagin induced transient Ca²⁺ release from fragmented sarcoplasmic reticulum. Dithiothreitol (DTT) and glutathione (GSH) partially blocked Ca²⁺ release induced by these oxidizing compounds. Pretreatment of alcian blue and plumbagin with DTT or GSH for more than 1 min was required to abolish the ability of the oxidizing compounds to release Ca²⁺. Mg²⁺ and ruthenium red completely blocked alcian blue-and plumbagin-induced Ca²⁺ release. These results suggest that oxidation of sulfhydryls on Ca²⁺ release channels induces Ca²⁺ release even in the presence of GSH in situ.     

Effect of decapacitation factor on the oxygen uptake of rabbit spermatozoa recovered from the uterus

Résumé L'addition d'un facteur de décapacitation préparé à partir du plasma séminal de lapin et de taureau a généralement produit une augmentation supplémentaire de l'absorption d'oxygène, quand il a été ajouté à la suspension de spermatozoïdes enlevée de l'utérus. Le facteur de décapacitation n'a exercé aucun effet stimulant similaire sur les spermatozoïdes de lapin avant l'incubation dans l'utérus et n'a montré lui-même aucune absorption d'oxygène appréciable.

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Dr.I. G. White is indebted to the Population Council for a fellowship and to the Australian Research Grants Committee for financial support. The authors are indebted to ProfessorC. W. Emmens for his interest and advice.