摘要:

Summary.The relaxing and the lactic acid forming effects on bovine tracheal muscle of adrenaline, nor adrenaline, isopropyl‐nor adrenaline and ephedrine were compared.All four drugs had both a relaxing and a lactic acid forming effect. The degree of relaxation tended to run parallel with the rise in lactic acid content.Drugs inhibiting glycol sis totally abolished the relaxing effect of all sympathomimetic amines that were studied.The concentrations of l‐adrenaline. l‐nor adrenaline, dl‐isopropyl‐nor adrenaline and 1‐ephedrine producing a maximal relaxing effect had a ratio of 1:

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01335.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01336.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.Supernatants from centrifuged cultures of the vitamin B12‐requiring alga,Euglena gracilis var. bacillary, contain a ther‐molabile factor, which combines with the vitamin. The complex of vitamin B12, and the “Euglena factor” thus formed cannot be taken up by the wild‐type E. coli E 35 and is non‐dialyzable through cellophane. The amount of the factor in the Euglena supernatants increases with the age of the Euglena cultures and is probably an excretion product of the Euglena cells. The factor, as regards its B12,‐binding effect, its thermo ability, and its non‐dialyzability, resembles preparations of the “intrinsic

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01337.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.1. Conduction velocity and amplitude of the action potential and fibre circumference were measured in isolated frog muscle fibres in a large volume of Ringer's solution.2. Conduction velocity was found to be a linear function of fibre circumference.3. The velocity in a fibre of 100 μ diameter (circumference 314 μ) at20°C was 2.44&0.05 m/sec. for spring frogs and 2.05&0.07 m/sec. for winter frogs. The total range in eonduction velocity at 20°C was 1.2–3.1 m/sec. for spring frogs and 1.0–2.76 m/sec. for winter frogs.4. The amplitude of the action potential, both at constant distance from the fibre surface and at 500 μ from the midpoint of the fibre, was relatively greater in fibres with large than in fibres with small circumference.5. The amplitude decreased steeply with electrode distance from the fibre up to 200 μ, and reached one tenth of the maximally measured value at a distance of about 600 μ.At equal distance the amplitude was 20 per cent smaller when the electrode faced the rounded side of an elliptical fibre, than when it faced the flat surface (large diameter twice the small).6. The findings with respect to conduction velocity and amplitude as a function of circumference are interpreted to indicate that the specific electrical properties of the membrane differ according to

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01338.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.Investigations have begun made on the critical temperature in naked man and the metabolic cost of maintaining an adequate heat balance below this point. The experiments were performed on a bicycle ergo meter in a cold room, by letting the subjects do just enough work to avoid becoming cold. The critical temperature was found to be approximately 26“ C, confirming earlier studies, and below this point the heat production increased approximately in proportion to the body‐to‐air temperature gradient, conforming with Newton's law of cooling and with data from most other mammals and

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01339.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.Animal and human tissues have been investigated for compounds activating the precursor of the plasminogen activator. In a few instances fibrinolysokinase activity was demonstrated in kidney tissue and lymph glands. All other organs investigated showed only activator activity and no lysokinase effect.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01340.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.1. The effect of 2.4‐DNP on the ATPase activity in the particulate aid soluble fraction of the rat diaphragm is investigated.2. A particulate fraction isolated from the diaphragm tip centrifugation at 8.000 × g for PO inins. showed ATPase activity which was accelerated by Ca++.and Mg‐+. 5 × 10‐4M 2.4‐DNP stimulated ATPase activit? Further. Most pronounced without the addition of Ca++and Mg++. Without the addition of inetal salts 2.4‐DNP accelerated the ATPase activity more strongly at pH 7.0 than at pH 9.0.3. The ATPase activity in the soluble fraction from the diaphragm obtained by centrifugation at 15.000 × g for 20 mins. was high and activated by Ca++and Mga‐+. 5 × 10‐4M 2.4‐DNP produced a slight stimulation of ATPase activity. Purified myosin ATPase was slightly stimulated by 2.4‐

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01341.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.1. The white rat lacks taste fibres discharging on the application of water to the tongue but it has “salt” fibres, which give not only a prompt but also a lasting response to the application of NaCl solutions as weak as 0.002 M.2. The rabbit displays a delayed response to water while the cat and the pig respond very promptly to the application of water upon the tongue.3. In all these animals (cat, pig and rabbit) the salt“ receptors are almost completely adapted to the saliva and adapt very quickly to the application of Ringer's solution. After a water rinse they all produce a phasic response to even as diluted NaCl solutions as 0.002 M.4. The high discrimination of salty solutions in the rat must rest upon its very highly sensitive “salt” fibres while the discrimination in thc animals that have “water” fibres is suggested to depend upon a dual system of “salt” and “water” fibres which are re

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01342.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.Hibernating and non‐hibernating hedgehogs were exposed to pure nitrogen an various mixtures of carbon dioxide and oxygen. Respectively. Temperature, respiratory rate, Heart rate and elec‐trocardiograpliic details were examined.Anoxia was tolerated by the hibernating hedgehogs for one to two hours. By the non‐hibernating animals for three to five minutes. Hibernating hedgehogs reacted upon prolonged anoxia with a, de crease in heart and respiratory rate. P—R and QRS duration increased, while Q—T was unchanged. In non‐hibernating animals respiratory and heart rates rapidly decreased. P—R and QRS did not change. while Q T decreased. In both groups the QRS‐amplitude decreased.Inhalation of 3 % carbon dioxide in oxygen resulted in no significant increase in respiratory rate, whereas 6 % and 9.5 % carbon dioxide provoked an increase in respiratory and heart rate with no consistent changes of the electrocardiogram, in both groups. The increase in respiratory ratc in non‐hibernating animals was somewhat greater than in guinea‐pigs, and in hibernating o

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01343.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.1. The inactivation of adrenaline and nor adrenaline in lymph collected from cats and. in one case, from a human being, was studied.2. In lymph the sympathetic hormones are fairly stable and even after several hours at 38° C the loss is small. Denaturation of the lymph proteins accelerates the inactivation rate of the sympathetic hormones.3. It is concluded thatin vivodestruction of adrenaline and nor adrenaline is strictly bound up with the tissue cells and that the extra cellular fluid rather to some extent prevents catechol amine destruction, a mechanism probably connected with its protein content

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1956.tb01344.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY