摘要:

Summary.In continuation of papers previously published by the author on renal function after infusion of a hyprrtonic sulphate solution into rabbits, the present paper gives an account of the function of the tubules during sulphate diuresis. The excretion of the substances contained in the plasma has been investigated through clearance determinations.1). Sulphate. The experiments show that before the sulphate infusion a considerable reabsorption of sulphate ion must be assumed. During the sulphate diuresis this is reduced until at the height of the diuresis it completely ceases, that is, the sulphate‐Excr.% = about 100.2). Ureashows in principle the same conditions.3). Chlorine. The reabsorption of chlorine is considerably reduced, but it is still thought possible to observe an active reabsorption of chlorine in the tubules. The chlorine‐Excr. % rises from less than 1 to 20–60 %.4). Glucose. During the sulphate diuresis the glucose Excr.% rises to more than 80 % gradually as the degree of concentration of the urine decreases.5). The decisive factor in the excretion of all the substances studied is the low C.index of the urine, resulting from the failing reabsorption of fluid.Here — as for the other substances — it holds good that the reabsorption decreases very rapidly when the C.index of the urine falls below 2.All the conditions observed during the sulphate diuresis can be explained by the filtration

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03025.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.In rabbits with chronic tubular nephritis produced experimentally by means of potassium bichromate a. m. Frandsensulphate diuresis experiments have been performed according to the principles previously laid down by the author (schou, 1943).In this way very low figures for the urine‐C.index (down to 1.03) are obtained and correspondingly high figures for the Excr. %, for water (up to 97 %) and for the dissolved substances here examined, namely sulphate, urea, and glucose, expressing a virtual cessation of the reabsorption in the tubules.For chlorine, however, the ability of reabsorption is in some degree retained.The features characteristic of the sulphate diuresis in healthy animals thus prove to apply also when the tubules are almost quite destroyed, which fact affords support for the theory that a failing tubular function is in any case the most important factor in the mechanism of the sulphate diuresi

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03026.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.By means of experiments on artificially perfused living hind‐limb preparations of cats the authors investigated the phosphate exchange between plasma and muscular tissue. The addition of insulin produced the familiar reduction of plasma phosphate as an indication of an immigration of phosphate ions in the musculature in excess of the emigration, but otherwise no alteration in the exchange of phosphate ions between plasma and muscles.Both before and after the addition of insulin the quantity of phosphate ion immigrating per time unit is so slight in proportion to the simultaneously assimilated quantity of glucose that a passage of the glucose into the muscle cells in the form of hexo‐sephosphates formed from the inorganic phosphates of the plasma may be regarded as out of the quest

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03027.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.Dark‐adaptation has been followed in cats and guinea pigs by measuring the absolute threshold of single or highly restricted discharges, isolated with micro‐electrodes.The curies obtained are of different types, as illustrated in fig. 1.The different adaptation curves can be explained by the assumption that there are two kinds of rods converging in different proportion towards the same fibre in the optic nerve, (i) real rods and (ii) cone‐like rods with adaptive properties similar to those of

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03028.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.Methods are described for studying the exchange of ions between the heart muscle of the frog and the bathing fluid along with the muscle contractions and for estimating the ion concentrations within the muscle cells.Analyses of the serum of a few frogs and toads have given values for potassium and calcium which are definitely higher than those used in Ringer solutions, but the differences appear to be of no consequence.Although the kation concentration of the bathing fluid is about 130 mM the total kations of the heart muscle dissolved in the quantity of water present will produce a higher concentration (about 170 mM), and evidence is presented to show that a fraction of the potassium which averages 82 mM in all, is chemically combined, so as to exert no osmotic pressure, and not readily exchangeable with42K.The calcium concentration is small (3–7 mM) and it seems probable that the calcium is mainly present in chemical combination.A large fraction of the potassium and calcium present in a heart can be removed by repeated treatment with small volumes of sodium solutions, and the quantities thus lost are reabsorbed from normal Ringer, if the washing out has riot been carried too far. The reabsorption of K+is not accelerated by higher concentrations. When potassium is lost sodium enters the cells and is again driven off daring the reabsorption process.The response of a heart to a potassium free solution is gradual and takes a few minutes to develop, during which the heart becomes show and somewhat irregular. When the solution is replaced by complete Ringer it again takes some minutes for the heartbeat to become normal.The response to changes in calcium concentration is much more abrupt. It is concluded that the action of K+and Ca++are mainly located in cell surfaces, that both ions can be to a certain extent replaced from the interior of the cells and that the replacement of Ca is much slower than that of potassium, while calcium from the bathing fluid acts almost at once.On the assumption that the effects of potassium and calcium are due to ions adsorbed or otherwise combined at the cell surfaces an attempt was made to determine the quantities adsorbed in the case of calcium, but these attempts failed.It is concluded that the heart muscle cells have the power of actively transporting potassium ions from the outside into the cells and sodium ions in the opposite directio

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03029.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.In a frog heart working on a solution in which 88 mM of Na and Cl are replaced with 175 mM glucose the sodium in the heart muscle cells is largely replaced by glucose. This replacement is reversible when the heart is put back into normal Ringer.Even saccharose can penetrate slowly into the muscle cells and replace the sodium.Inconclusive evidence (a single experiment) is presented indicating that the sodium within the cells can be reduced below the outside concentration.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03030.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.By means of tyrosinase from meal‐worms, indoline derivatives are formed from tyrosine, adrenaline and other related substances.It is shown that the effect on reticulocyte ripening of tyrosine. adrenaline, βp‐oxyphenylisopropylaniine and tyramiae is only 10 to 1 % of the effect of the corresponding indoline derivatives: hallachrome, adrenochrome etc. Dioxyindole and dioxyindole‐carbonic acid have no ripening effect.Tyrosine is decomposed by red blood corpuscles and from red blood corpuscles we have prepared enzymes able to convert tyrosine and dioxyphenylaniine into substances more active towards reticulocyte ripening. The same enzyme preparation is able to form melanine from tyrosine and dioxyphenylalanine, and to give rise to the oxygen consumption in solutions of these substances.This makes it possible that hallachrome can be formed from tyrosine in the erythrocytes and a calculation shows that the enzyme concentration inside the erythrocytes is sufficient to support the assumption that the effect of tyrosine on the reti‐culocytes is due to its conversion into liallachrome with the co

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03031.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.1). Our investigations on the microphone effect on guinea‐pigs have been performed with a new technique; the anode used being a freshly chloridised silver wire applied directly to the apex of the cochlea. This method seems to yield better results than the methods previously used.2). The microphone effect on guinea‐pigs comprises at any rate a frequency range of from about 30 to 14,500 cycles. The “electrical audiogram” taken on guinea‐pigs corresponds fairly closely to the normal audiogram taken on human subjects.3). The microphone effect is quite unaffected by urethame, salicylic acid, quinine, allypropynal, adrenaline, prostigmine, and calcium. Large quantities of physiological saline solution injected intraperitoneally does not influence the microphone effect. After injection of 30 % NaCl intraperitoneally irregular but not reduced potentials are observed. Reduction only sets in simultaneously with death. Magnium sulphate in a 20 % solution yielded the same result.4). At the incidence of death the microphone effect is immediately reduced to about 1/5 of its original size and during the succeeding hours it decreases quite gradually till finally it completely ceases.5). The microphone effect must presumably be regarded as a necessary link in the perception of sound. It is probable that tones can be heard by the animal within the same range of frequencies as it is possible to demonstrate the microphone effect with the tech

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03032.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.Description is given of the author's modification of Mcfarlane'sMethodfor determination of the copper content of blood and serum by means of diethyl‐dithiocarbamate.Experiments show that acid ashing and trichloroacetic acid treatment give the same results.For alkalinization the addition of ammonia in excess is unsuitable as it may be precipitated in the amyl alcohol as ammonium carbonate. In determinations on whole blood the presence of iron after ashing may cause an error which is avoided most easily by adding the thiocarbamate dissolved in a solution of pyrophosphat

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03033.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY

摘要:

Summary.1). In fully‐nourished animals casein shows a negative chemo‐taxis. After some days without nitrogen in the food this aversion decreases considerably. The quotas approach 50 and often rise considerably above it, so that the animals in certain cases practically speaking consume only the casein‐rich food, while they leave the nitrogen‐poor food almost, untouched.2). In fully‐nourished animals serum albumin is almost neutral (quota value round abut 50). After N‐starvation the average values for the quotas rise.3). The fully‐nourished animals the wheat gluten has already a marked positive chemo‐taxis (quota value up to 71).4). The changes in the animals' selection of food must be connected with changes in the bodily condition on account of lack of nitrogen. The food in the 2 cups is the same and has the same taste in the preparatory experiments when the animals are fully nourished, as in those carried out with the same animals after a period

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1944.tb03034.x

出版商:Blackwell Publishing Ltd    

年代:1944

数据来源: WILEY