摘要:

Summary.1The net ionic flux through the frog skin and its electrical permeability resistance (defined as the d. c. resistance minus the high frequency a. c. resistance) were measured simultaneousely.2When the concentration of the outside solution (determined conductometrically) was raised from 0.25–10 mM/1 there was but little change in the net ionic outflux through the skin, but a considerable decrease in the permeability resistance. The composition of the inside solution was kept constant (Ringer).3An empirical mathematical expression was found which described the permeability resistance of the normal frog skin as a function of the concentration of the outside solution. An expression referred to as the “reduced permeability resistance”, or rather its inverse, was found to be closely related to the net ionic outflux when the concentration of the outside solution was 0.25–10 mM/I.4Under the influence of various drugs and of mechanical trauma, the inverse of the “reduced permeability resistance” was subjected to changes which were closely paralleled in their time course with alterations in the net ionic flux throu

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00698.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Summary.1Section of the sinus nerves in vagotomised cats suffering from the effects of haemorrhage, abolishes Mayer waves previously evident in the arterial blood pressure record.2Blocking of the vagi, by cooling, in bled animals in which the sinus nerves have been previously cut, similarly abolishes the presence of Mayer waves.3Carotid occlusion in intact or vagotomised cats suffering from the effects of haemorrhage, causes the appearance of large periodic variations in the arterial blood pressure record. These periodic variations do not appear upon carotid occlusion if the sinus nerves have been sectioned. Similarly if the carotid body chemoceptors have been destroyed by intra‐sinusal injection of acetic acid occlusion of the common carotid arteries causes little change in the blood pressure record.4The amplitude of the periodic waves of blood pressure caused by clamping the common carotid arteries in animals with intact vagi, is reduced by applying cold‐block to the vagus nerves.5Occlusion of the external carotid arteries reduces the variations of blood pressure which occur during occlusion of the common carotid arteries.6A hypothesis is advanced to explain the causation of the Mayer waves in terms of rhythmic excitation of the chemocep‐tor mechanisms occurring in animals suffering from the effects of haemorrhage.7Periodic respiration commonly accompanies Mayer waves and in such cases respiration assumes a rhythmicity identical with that of the blood pressure. A similar hypothesis to that given for the Mayer waves may be considered as an explanation for Cheyne‐Stokes br

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00699.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Summary.The pharmacological properties of trimethyl‐, dimethylethyl‐, methyldiethyl‐ and triethyl‐phenylammonium have been investigated.The toxicity of the substances in mice and rabbits was determined. The cause of death in all the cases appeared to be peripheral paralysis of respiration.Trimethyl‐, dimethylethyl‐ and methyldiethyl‐phenylammo‐nium had a parasympathicomimetie effect on the blood‐pressure. The parasympathicomimetic activity diminished as the number of ethyl radicals increased.Triethylphenylammonium decreased the blood‐pressure. This effect was not reversed by atropin.Trimethyl‐, dimethylethyl‐ and methyldiethyl‐phenylammo‐nium had a “nicotinic‐stimulating” action. This effect too diminished according as the number of ethyl radicals increased. Triethylphenylammonium had no “nicotinic‐stimulating” action.All the substances had a paralyzing effect on the sympathetic ganglion. It was most marked in dimethyl‐ and triethylphenylammonium and least in trimethylphenylammonium.All the substances examined have shown, in muscle‐nerve preparations, a curariform effect. The effect was strongest in the trimethyl compound and diminished according as the number of ethylradicals increased.The effect of these substances on the isolated rabbit heart have been tested.The syntheses of trimethyl‐, dimethylethyl‐, methyldiethyl‐ and tr

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Summary.The changes of the action potentials of the muscle under ether anesthesia have been investigated. The changes have been compared with those produced by curare. The results were:1The amplitude of the action potentials is reduced under ether anesthesia. The reduction depends to a great degree on the frequency of stimulation, and the amplitude varies strongly with the duration of the stimulation. In general the reduction is more pronounced the higher the frequency of stimulation.2The amplitude of the action potentials varies under ether anesthesia in a manner similar to that of the mechanical response of the muscle.3The changes recorded in the amplitude of the action potentials are in their main features of the same character under the influence of ether as of curare.4Under ether anesthesia a depression of the amplitude of the action potentials takes place during the period of stimulation. The depressing effects at higher and lower frequencies are of different character, and produce qualitatively different changes of the action potentials.5Tetanic contractions exert an augmentative effect on the amplitude of the action potentials under the influence of ether as well as of curare.6The action potentials which are recorded from a natural muscle activity during ether anesthesia show a corresponding reduction as the reduction recorded after artificial stimulation. 7. Apart from changes in the amplitude the qualitative changes of the action potentials under the influence of ether are entirely different from those produced by curare.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Summary.1Stimulation of the central end of the superior laryngeal nerve in cats causes an increased motility of the small intestine. This augmentation of intestinal movement is produced via a reflex pathway involving the vagus nerves. Thus the effect is abolished by section of the cervical vagi.2Stimulation of the superior laryngeal nerve has no effcet on the intestinal movements after atropinisation of the animal.3It is suggested that this reflex increase of intestinal motility is intimately related to the swallowing reflexes.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY

摘要:

Summary.It is shown that injection of propyl alcohol gives rise to the formation of acid, which is ethersoluble, volatile and is extracted by toluene at the same rate as propionic acid, so that it is made very probable that this acid is formed.At the same time the concentration of another ethersoluble but not toluenesoluble acid increases. Probably it is an accumulation of lactic acid. Propionic acid seems to be formed and eliminated at a constant rate partly independent of the concentration of propyl alcohol.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1950.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1950

数据来源: WILEY