摘要:

Summary.Indirect maximal tetanic stimulation of the tibialis muscle of the cat and the pigeon at frequencies of about 45 p. sec. frequently lead to a gradual increase in tension of the muscle to a considerable extent.This secondary rise in tension is accompanied by a diminution of the action potentials. When a series of short tetanic stimulations are applied to the nerve the maximal tension of each tetanus shows, after a short depression, a gradual increase up to a maximum followed by a fall.In the soleus muscle of the cat this phenomenon is much less obvious at frequencies of 15–40 p.s. and there are only slight changes in action potentials at these stimulating frequencies.The phenomenon described here appears to be closely related to the post‐tetanic potentiation of a single muscle twi

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00269.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Zusammenfassung.1Eine Methode zur Bestimmung der Pyrophosphatase‐wirkung in Blut bezw. Plasma, Serum und Erythrozyten wird beschrieben.1Das pH‐Optimum für die Pyrophosphatasewirkung im Blut liegt bei 7.4.2Die Pyrophosphatasewirkung wurde im Blut und Plasma bei Mensch, Hund, Pferd und Rind bestimmt. Mit Hilfe dieser Werte und der Hämatokritwerte wurde die Wirkung in den Erythrozyten berechnet. Blut der beiden erstgenannten enthält ungefähr10mal mehr Pyrophosphatase als Rinderblut, und Pferdeblut ungefähr 5mal so viel. Die Pyrophosphatase kommt hauptsächlich in den Erythrozyten vor, Plasma enthält nur unbedeutende Mengen.3Wird die Pyrophosphatasewirkung direkt in vom Plasma befreiten Erythrozyten bestimmt, so enthält man bedeutend höhere Werte als bei der Berechnung der Wirkung aus den Werten für Blut und Plasma. Die Zunahme variiert zwischen dem Doppelten und 18‐Fachen. Die Enzymwirkung in den Erythrozyten verhält sich bei Pferd, Mensch, Hund und Rind wie 76: 57: 17: 1.4Irgendeine Korrelation zwischen dem Gehalt der Blutkörper an Pyrophosphaten und Pyrophosphatase liegt nicht vor.5Wird die Bestimmung der Pyrophosphatasewirkung in einer Reaktionsmischung ausgeführt, die mit den Blutkörpern isotonisch ist, so erhält man keine Enzymwirkung. Die Pyrophosphatase in den Blutkörpern kann folglich nicht ausserhalb diesen zur Wirkung gelangen, bevor die Erythrozyten hämolysiert sind. Hierin unterscheidet sich die Pyrophosphatase von der Phosphormonoesterase.6Plasma bezw. Serum enthält einen Stoff, der die Pyrophosphatasewirkung stark hemmt. Dieser Umstand erklärt das in Punkt 4 genannte Verhalten.7Bei der Aufbewahrung von Blutproben bei ungefähr 20° C. für eine Zeit bis zu 3 Tagen ändert sich die Pyrophosphatasewirkung nur unbedeutend. In vom Plasma befreiten Blutkörperaufschlämmungen nimmt die Pyrophosphatasewirkung nach 24 Stunden lan

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00270.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Summary.1Transamination has been studied in cattle diaphragm muscle. The reaction proved, with slight discrepancies, the well known characteristic properties.2The reaction between α‐ketoglutaric acid and amino acids or peptides was facilitated by preliminarily freezing the minced muscle. A disappearance of ketonic acids could not be demonstrated. The transamination was not inhibited by bromoacetate or sodium arsenite.3Glycyl‐aminobenzoic acid and valyl‐glycine could be used as amino group donators. In the opposite way glutamic acid apparently reacted with α‐hydroxy and α‐ketonic acids in peptide chains.4Muscles from different animals displayed some variability in the reaction between c‐ketoglutaric acid and unnatural amino acids and rac

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00271.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Summary.After a survey of earlier literature on the passage of ethyl alcohol from the gastro‐intestinal tract to the blood, the factors are discussed that may possibly have to bear on this passage, the basis of the discussion being the laws of diffusion. From these laws formulae have been deduced, in which the percentage of the blood alcohol, the blood flow through the mucous membrane of the stomach and the concentration and the volume of the alcoholic solution ingested have been taken into consideration. The validity of these formulae is not only confined to the diffusion of alcohol but also applies to all the cases in which a pure process of diffusion is concerned.By means of a series of determinations of the alcohol percentage in the contents of the stomach of cat with intact and ligated pylori as well as on human subjects—both normal individuals and patients—by means of fractional withdrawal of ingested alcohol, an attempt has been made to show that the passage of alcohol through the mucous membrane of the stomach is to be regarded as a pure process of diffusion. The results of the experiments are:1). The absorption of ethyl alcohol from the stomach follows the laws of diffusion. This means that the greater the concentration of the alcohol ingested, the more rapidly will absorption take place with a higher and earlier blood alcohol maximum (cp fig. 1). The so‐called diffusion factor is constant in the case of constant blood flow and constant volume.1). A cat with ligated pylorus absorbs in 30 min about 38% of the alcohol ingested, when given in a solution of 5 per cent by volume, about 62% after 60 min and 76% after 120 min; of a solution of 17 per cent proportionally more is absorbed.1). On human subjects with closed pylori the corresponding figures for a solution of 5 per cent by volume are 40% after 30 min, 70% after 60 min and about 100% after 120 min. If the stomach is emptied, on the other hand, the whole quantity of alcohol ingested can disappear in les

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00272.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Summary.The concentration of visual purple has been determined photoelectrically during dark adaptation of previously light adapted frogs at 22.4 and 8°.At the higher temperature pilocarpine slightly enhances, and atropine definitely suppresses the rate of regeneration of visual purple in live frogs. At the lower temperature neither substance has any effect on the regenerative processes.The results are interpreted as further evidence in favour of the dual nature of visual purple regeneration. Only the process sensitive to temperature is in this particular instance sensitive to the drugs.Some results with regeneration in excised eyes under the influence of pilocarpine and atropine are also reported

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00273.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Zusammenfassung.Es wird eine einfache Methode zur Bestimmung des Harnstoffstickstoffs an 0.2 ml Blut beschrieben. Ihr Vorzug besteht darin, dass das Blut in eine Lösung gebracht wird, die gleichzeitig als eine für optimale Ureasewirkung geeignete Pufferlösung und nach leichter Ansäuerung als Eiweissfällungsmittel dient. Man erhält ein eiweissfreies Zentrifugat und nimmt darauf, in Gegenwart von Gummi arabicum als Schutzkolloid, nach direkter Nesslerisierung eine kolorimetrische Bestimmung vor.Für einen Geldbeitrag zur Ausführurig der Arbeit möchte ich der ←Kungl. Fysiografiska Sällskapet→ in Lund meinen Dan

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00274.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

Summary.The object of the work has been to investigate, by means of experimentsin vitro, the effect of vitamin D on calcium and phosphorus metabolism in rat.The normal bone has the ability to take up calcium from the incubation solution under certain conditions and, on the other hand, to give up calcium into the calcium‐free incubation solution.The bone was not able to take up inorganic phosphorus in the incubation experiments. On the other hand the excretion of inorganic phosphorus into the solution could always be demonstrated—both in incubation solutions with and without phosphorus.The bones of rats which had received large amounts of vitamin D seemed to be able to take up relatively more calcium than the bones of normal rats. On the other hand it is possible that the bone is then to some extent more than normally able to take up calcium and phosphorus.With regard to the deficiency of vitamin D, a tendency towards a decreasing uptake of calcium and increased loss of calcium was noted.The experiments support the view that vitamin D has a direct influence upon the mineral metabolism of the b

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1940.tb00275.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY