bluuebunny/crossref_metadata_2025 huggingface dataset:
THE STRUCTURE AND MOVEMENTS OF THE CARDIA
Authors: M'Swiney B. A.
Published: December 2014

It is suggested that the movements of the circular muscle of the cardia are controlled by the “tonus” and contractions of the sling, or internal oblique, fibres of the stomach. The following considerations seem to indicate this.

1. The arrangement and relative development of the internal oblique fibres in the stomach of different animals.

2. The type of response obtained in isolated strips from the cardia and neighbouring parts of the stomach.

3. The co‐ordination of the movements of the cardia with those of the stomach.

4. The function of the sling in maintaining the shape and position of the stomach as determined by the contractions and tonus of the sling.
THE EFFECT OF SHIVERING ON THE RESPIRATORY QUOTIENT IN PANCREATIC DIABETES
Authors: Chaikoff I. L. , Macleod J. J.R.
Published: December 2014

1. Shivering in response to cold raises the respiratory quotient and the oxygen consumption of normal and depancreatised dogs to a similar extent. Since no disturbance of the acid‐base equilibrium of the organism can be detected, the raised respiratory quotient points to an increase in oxidation of carbohydrate.

2. The increase in R.Q. is marked at the beginning of shivering, but returns later towards the basal level although the increased oxygen consumption is still maintained. This is interpreted as indicating that oxidation of preformed carbohydrate is the only process which is stimulated when the shivering starts, but that a process of gluco‐neo‐genesis sets in later and thus depresses the quotient although as much carbohydrate is still being oxidised.
NON‐SPECIFIC CHANGES IN THE OPSONIC POWER OF RABBIT SERUM PRODUCED PHYSICALLY THROUGH THE INTRAVASCULAR INJECTION OF FOREIGN PARTICLES IN SUSPENSION
Authors: Elvidge A. R.
Published: December 2014

The intravenous administration of (chemically inert) quartz suspensions causes a physico‐chemical alteration in the white‐cell plasma relations due to non‐specific changes produced physically in the rabbit's blood serum, which results in a profound decrease in the ability of the polymorphs to phagocyte Staphylococcus pyogenes aureus in vitro in the presence of their own serum. If serum from a normal rabbit is substituted, the cells again become able to phagocyte. If cells from a normal rabbit are incubated with the “treated” rabbit's serum, they tend to lose their phagocytic ability.

The phenomenon is due to a lack of some substance, “opsonin,” from the serum of the treated animal. This lack can be compensated for by the addition of a normal control serum.

It has been found possible to vary experimentally by a physical method the “opsonic” content of the blood serum of a rabbit without the use of vaccines.

I wish to acknowledge my indebtedness to Professor
John Tait for much helpful criticism in preparing this paper for press.
ON THE GENETIC NATURE OF THE TIME OF ATTAINMENT OF PUBERTY IN THE FEMALE MOUSE
Authors: Mirskaia L. , Crew F. A. E.
Published: December 2014

In the mouse stocks examined it was found that relatively early and relatively late attainment of sexual maturity are genetic characters, and are not influenced in their expression by differences in environmental conditions whenthe animals are kept at an optimum and constant temperature.

Environmental factors (food and general care), however, do condition the pregnancy rate‐that is to say, the percentage of pregnancies following upon first mating at the first, second, and third cestrous cycles is determined by non‐genetic factors.
AN IMPROVED FLUID FOR MAMMALIAN SPERM‐SUSPENSIONS
Authors: Baker John R.
Published: December 2014

A modification is suggested as an improvement in the buffered glucosesaline fluid for mammalian sperms given in a previous paper by the author.
CALCIUM IN PERFUSION ŒDEMA
Authors: Gunn J. W. C.
Published: December 2014

Perfusion of the vessels of the South African clawed frog with solutions containing various amounts of calcium chloride showed that increase of calcium diminished the perfusion œdema.

The effect is possibly not due to the specific action of calcium ions, but to the increased salt concentration of the perfusing fluid.
THE ACTION OF JANUS GREEN UPON BLOOD‐VESSELS
Authors: Ettinger G. Harold
Published: December 2014

1. Janus green exerts a powerful constrictor effect upon the pulmonary arteries of the guinea‐pig, rabbit, and cat, so great and sustained indeed that the obstruction to the blood‐flow may cause death through cardiac failure. The coronary arteries may also be affected, causing ventricular fibrillation. The systemic blood‐vessels of the frog, guineapig, rabbit, and cat are also moderately constricted.

2. The constrictor action of Janus green is tachyphylactic. It is more readily demonstrated and can be provoked with smaller amounts in the perfused surviving blood‐vessels than in the living animal, but in the former the perfusion with foreign sera and a high oxygen content of the tissues tend to diminish the reaction.

3. Strips of the aorta of the rabbit and cat, of the pulmonary artery of the rabbit, and of the carotid artery of the ox all fail to respond to solutions of Janus green in a Magnus bath. It has not been possible to reconcile this observation with the results described above.

4. The smooth muscle of the uterus, bronchiole, and ileum fails to respond to Janus green, but duodenal movements are depressed.

This research was commenced in Edinburgh in 1928–29, in Professor Sharpey‐Schafer's laboratory. The experiments were continued at Queen's University upon my return to Canada, and in the Medical Research Laboratory of Professor Banting in Toronto.

I am indebted to Professor HAY, Kingston, for the photographs.

The expenses of the experiments performed in Edinburgh were met in part by a grant from the Earl of Moray Fund for the promotion of research in the University of Edinburgh.
PREGNANCY CHANGES IN THE RABBIT'S UTERUS AND THEIR RELATION TO ENDOCRINE ACTIVITY. III
Authors: Robson J. M.
Published: December 2014

Daily injections of anterior pituitary lobe substance (together with an antiseptic, quinanil) into mature non‐pregnant or pseudopregnant rabbits is followed by luteinisation of the ovaries. The uterus shows typical condition, viz. marked progestational proliferation of the endometrium, but no inhibition of the reaction to pituitrin. This “dissociation” of the uterine responses is never observed during pseudopregnancy or after a single injection of gonadotropic hormone.

The injection of a standard corpus luteum extract into animals receiving daily anterior lobe injections does not, as a rule, bring about inhibition of the pituitrin reaction. The combined daily injection of anterior lobe and α‐hormone (œstrin) usually brings about inhibition.

Animals injected intravenously with β‐free gonadotropic preparations from pregnancy urine for prolonged periods do not show dissociation of the uterine responses.

It is concluded that β‐hormone is necessary for the development of the inhibitory reaction. A tentative explanation of the results obtained with different gonadotropic preparations is offered.

I am indebted to the Medical Research Council for a grant in aid of this work.
ARGINASE STUDIES.—I. THE RELATION BETWEEN THE ACTIVITY OF THE ENZYME AND THE CONCENTRATION OF HYDROGEN IONS
Authors: Hunter Andrew , Morrell Joseph A.
Published: December 2014

1. The range of pH over which arginase exerts a measurable activity is 4–8 to 1l·5.

2. The point of maximum activity is at or near pH 9·8.

3. The pH activity curve is therefore strikingly unsymmetrical.

4. In the alkaline range of its activity, beginning at about pH 8, the enzyme, even in the presence of its substrate, undergoes increasingly rapid destruction.

5. This accounts in all probability for the very rapid fall of activity on the alkaline side of the optimum.

6. The rising limb of the activity curve is not a simple symmetrical S‐shaped curve, but has a complex form, closely resembling the titration curves of certain proteins.

7. The possible interpretation to be put upon this observation is briefly discussed.
THE TEMPERATURE COEFFICIENT AND THE APPARENT ENERGY OF ACTIVATION OF THE ENZYMATIC HYDROLYSIS OF ARGININE; WITH ADDITIONAL OBSERVATIONS UPON THE STABILITY OF ARGINASE UNDER VARIOUS CONDITIONS
Authors: Hunter Andrew
Published: December 2014

The temperature coefficient of the arginine‐arginase reaction at a pH of 7·35 varies from 2·70 for 0°–10° to about 1·54 for 40°–50°. At pH 9·85 it is smaller, and falls from 2·34 for 0°–10° to 1·73 for 20 °‐30°. The calculated energies of activation corresponding range from 15,200 to 8660 and from 13,000 to 9600. Incidental observations have emphasised the great lability of the enzyme, and particularly its susceptibility to heat, in alkaline media. Its relative stability near the neutral point has been confirmed, although even there it has been found to undergo gradual destruction at temperatures as low as 30°.
THE OXYGEN CONSUMPTION OF THE ISOLATED UTERUS OF THE RAT AND MOUSE
Authors: Khayyal M. A. , Scott C. M.
Published: December 2014

1. The oxygen consumption per unit weight of the uteri of mice and rats shows a cyclical variation; it remains uniform during the greater part of the cycle, but is approximately doubled during the latter part of diœstrus.

2. The oxygen consumption rate of the whole uterus of mice and rats is at its maximum during the œstrous phase and at its minimum during the latter part of diœstrus. This effect is brought about by the great variations in the weight of the organ during the œstrous cycle.

3. The oxygen consumption rate per unit weight of the uterus of mice and rats varies inversely as the cube root of the body‐weight of the animal.

We thank Professor A. J. Clark for his help during this investigation. The expenses were paid by a grant from the Moray Fund of Edinburgh University.
THE GLUCOSE AND LACTATE CONSUMPTION OF THE DOG'S HEART
Authors: Evans C. Lovatt , Grande F. , Hsu Fong Yen
Published: December 2014

1. When the volume of blood in a heart‐lung circuit was increased the lactate in the blood tended to rise, and vice versa. This is as predicted from the facts that lactate arises by glycolysis in the blood and is removed by the heart. Estimation of the amounts of glucose utilized by the heart and based on the fall of blood sugar in heart‐lung preparations are certain to be too high if the rates of glycolysis in the blood and in the lungs are ignored or assessed at too low values.

2. To obviate the attempt at such calculations in which the lungs introduce an uncertain factor, recourse was had to an isolated heartoxygenator circuit. By the use of this the glucose and lactic acid utilization of the dog's heart were assessed at an average of 70 mg. and 200 mg. respectively, per 100 grm. heart/hr., the blood being oxygenated by a mixture of 5 per cent. CO2 and 95 per cent. oxygen, and each ventricle, doing reasonable amounts of work under normal conditions of arterial pressures, at a temperature of about 37° C.

3. There was considerable fluctuation in the glucose usages in different hearts, but a general tendency for lactate and glucose utilizations to be reciprocally related. The sum of lactate and glucose utilizations was in the majority of experiments insufficient if combusted to account for the known oxygen usages of heart muscle. The rate of usage of either constituent was increased if its concentration in the blood was increased and, below certain critical levels, was reduced when its concentration was reduced.

4. Addition of insulin, the blood sugar being normal or low, increased the utilization of glucose but did not clearly affect that of lactic acid, whether this was at high or low concentration in the blood.

The authors express their thanks to the Government Grants Committee of the Royal Society for a grant to one of us (C. L. E.), which covered part of the cost of animals. Also to Mr J. Trendall and Mr V. C. Tindley for skilled help in constructing and maintaining the necessary apparatus.
ESTIMATION OF THE FERMENTABLE CARBOHYDRATES IN RABBIT LIVER
Authors: Purves C. B.
Published: December 2014

1. Estimation of glycogen and free sugar failed by 25 ± 8 per cent. to account for all of the fermentable carbohydrate in rabbit liver. The deficiency was attributed to the presence of a fermentable polysaccharide which was destroyed during the glycogen determination and was insoluble in 90 per cent. alcohol. It was extracted from liver by 32 per cent. alcohol.

2. The only copper‐reducing substance extracted from liver by 90 per cent. alcohol agreed, in its optical rotation and copper‐reducing power, with glucose, which is in all probability the “free sugar” of the liver.

3. At death the “free sugar” content of liver, expressed as glucose, was not more than 0·2 per cent., but subsequent to death it rapidly increased. This increase was accompanied by a nearly equivalent decrease in the percentage amount of glycogen.

The author wishes to acknowledge his indebtedness to Professor J. J. R. MacLeod, who suggested this work, and to the Carnegie Trust for a Teaching Fellowship.
THE EFFECT OF ADRENALINE AND OF INCREASED WORK ON THE CARBOHYDRATE METABOLISM OF THE MAMMALIAN HEART
Authors: Bogue J. Yule , Evans C. Lovatt , Grande F. , Hsu F. Y.
Published: December 2014

1. Increase in the energy expenditure of the dog's heart by the addition of adrenaline to the circulating blood increases the utilization of both sugar and lactate.

2. The same holds true for increase in energy expenditure by raising the mechanical work done.

3. Cardiac muscle appears to differ fundamentally from skeletal muscle in the ease with which it uses lactate.

4. It is suggested that the lactate is burned by the tissue to yield energy, whereas the sugar is used to replace glycogen usage. When the blood sugar and lactate have fallen to a low level the heart glycogen is drawn upon, especially if the energy expenditure has been high.

Part of the costs of this research have been defrayed by a grant from the Royal Veterinary College to one of us (J. Y. B.).
ON THE RELATION BETWEEN THE SITE OF INJECTION OF ANDROSTERONE AND THE COMB RESPONSE IN THE FOWL
Authors: Greenwood A. W. , Blyth J. S. S.
Published: December 2014

1. Injections of androsterone directly into the substance of the capon's comb produced a response greater than that elicited by the same dose when injected intramuscularly in the pectoral region.

2. In a preliminary test of the effect of the hormone in intact birds, two females responding to the treatment, showed less increase in comb size than the capons, as recorded in the length plus height measurements, but developed well‐marked swellings at the base of the comb, which are considered to be manifestations of a local effect. A normal male showed no reaction to the same treatment, while an incompletely castrated male, with a comb similar in size to those of the females, gave a marked response.

3. The significance of the results is briefly discussed.
THE OXYGEN SUPPLY OF THE LIVER
Authors: McMichael John
Published: December 2014

1. In the cat the liver obtains about two‐thirds of its oxygen from the portal vein under normal conditions of blood‐pressure. Obstruction of the portal vein to a lobe causes central degeneration in the lobules.

2. When the blood‐pressure is lowered by hæmorrhage and shock, the oxygen content of the portal venous blood is proportionately diminished, and the liver becomes more and more dependent on the hepatic artery for its oxygen.

3. In the rabbit the liver is almost entirely dependent on the hepatic artery for its oxygen, and gets only an insignificant amount from the portal blood.

4. Irritation of the hepatic nerves by a ligature may cause a temporary diminution of the flow through the liver by causing vasoconstriction of the portal venules within the liver. This effect, however, is so transient that it does not play any significant part in determining the liver degeneration which results from ligature of the hepatic artery.

5. Temporary occlusion of the hepatic artery does not lead to reactive hyperæmia in the liver.

The expenses of this Research have been partly defrayed by a grant from the Medical Research Council.
STUDIES ON THE CHEMICAL NATURE OF THE ANTIFERMENTING PRINCIPLE IN BLACK TIGER SNAKE VENOM
Authors: Chain E. , Goldsworthy L. J.
Published: December 2014

The anti‐fermenting principle in black tiger snake venom is destroyed by heat to a large extent, and is almost completely destroyed by precipitation with methyl alcohol, ethyl alcohol, and acetone. It does not dialyse through cellophane membranes. Ammonium sulphate and sodium chloride precipitate it partially from aqueous solutions. It is completely destroyed by alkali, but is relatively stable in acid solutions. Exposure to the air in neutral solution for several days does not appreciably affect the activity. Pepsin destroys it rapidly.

These properties in our opinion show conclusively that the active principle is a protein. Granting the correctness of this conclusion, the fact that it acts in very great dilutions suggests that the inhibitory effect on the fermenting enzyme complex is itself of enzymatic nature.
A COMPARISON OF LYSOZYME PREPARATIONS FROM EGG‐WHITE, CAT AND HUMAN SALIVA
Authors: Roberts E. A. H. , Maegraith B. G. , Florey H. W.
Published: December 2014

1. A highly purified specimen of cat lysozyme and a less pure one of human lysozyme have been prepared.

2. Chemical and serological comparison shows clear‐cut differences between them, though all specimens have the power to dissolve M. lysodeikticus.

We are indebted to the Medical Research Council for a grant towards the expenses of this work.
THE HYPOTHALAMUS AND GASTRIC MOTILITY
Authors: Heslop T. Stewart
Published: December 2014

1. Anterior hypothalamic stimulation produces a marked increase in gastric tone and motility.

2. Posterior hypothalamic stimulation produces a much less marked converse effect and seems to be limited to a transient relaxation of the pyloric end of the stomach.

This work was carried out at the Buckston Browne Surgical Research Farm of the Royal College of Surgeons of England.

I am indebted to Mr. F. Watson for his technical assistance.
THE ACTION OF DRUGS ON THE ISOLATED PERFUSED LUNGS OF THE PIG
Authors: Petrovskaia B.
Published: December 2014

The lungs of the pig isolated and perfused with the animal's own blood are not suitable for testing bronchial responses to the injection of drugs. Sooner or later the preparations exhibit œdema and prevent measurement of the tidal air. This statement applies to preparations made from animals bled to death under Pernocton and local anæsthesia. Vascular responses to drugs are easily obtainable and, in respect of adrenaline, exhibit a remarkable uniformity from one preparation to another. Adrenaline invariably reduces the pulmonary arterial pressure in freshly perfused lungs, and augments it during later stages of perfusion. It has been reported that a similar phenomenon may on rare occasions occur in the dog [Alcock, Berry, and Daly, 1935]. How far the adrenaline pulmonary effect depends upon the maintenance of vessel tone in some parts of the vascular bed, or to physicochemical changes in the blood or lung tissues under the artificial conditions of persusion, there is insufficient evidence to decide.

In isolated pig's lungs under negative pressure ventilation and perfused at constant volume inflow with defibrinated blood:

1. Adrenaline reduces the pulmonary arterial pressure in freshly perfused preparations and augments it during later stages of perfusion; ergotoxine reverses the pressor effect. Adrenaline dilates the bronchi.

2. Small doses of A.Ch. tend to lower, and larger doses to raise, the pulmonary arterial pressure in ergotoxinised preparations. The bronchi constrict.

I wish to express my thanks to Professor I. de Burgh Daly for his advice and encouragement during this work, and to the Moray Endowment Committee, who defrayed the expenses of the research.
THE ACTION OF MAGNESIUM SULPHATE ON THE INTESTINE OF THE CAT
Authors: Lium R. , Florey H. W.
Published: December 2014

1. Isotonic MgSO4 slows the absorption of isotonic NaCl solutions in the intestine of the cat. It does not influence the absorption of glucose solutions. It does delay slightly the absorption of distilled water.

2. Isotonic MgSO4 is no more irritating to the colon than isotonic NaCl as evidenced by histological studies. Its action in producing purgation is probably that of diminishing absorption and thereby producing mechanical stimulation for defæcation by the increased bulk.

3. MgSO4 in small doses produces loose and watery stools in cats for several days. This may be due to its effect in slowing the absorption of other crystalloids.

4. Solutions of NaCl are best absorbed from the ileum; of glucose, best from the jejunum in cats.

5. Decapitate cats cannot be considered to be completely normal with regard to intestinal motility. Washing and excessive handling of the colon tend to make it irritable and give inconsistent results in acute experiments.
THE ACTION OF SOME ANDROGENIC SUBSTANCES ON THE IMMATURE FEMALE RAT AND GUINEA‐PIG
Authors: Groome J. R.
Published: December 2014

The Intact Rat.

Six immature female rats injected with 500γ Testosterone propionate daily for 8 days showed on the 9th day:

1. An abnormal increase in body weight, not due to fat deposits.

2. The abnormal presence of Graafian follicles, and in four cases of corpora lutea in the ovary.

3. Hypertrophy of the uterus, in one case having an œstrous, and in the others a progestational appearance, which might be genuine pseudo‐pregnancy.

4. Mucification of the vaginal epithelium.

5. Hypertrophy of the female preputial glands.

6. No mammary development, with the exception of one animal.

7. Hypertrophy of the clitoris‐like organ.

It is suggested that Testosterone propionate is directly responsible for all these changes; that the mammary glands are less susceptible to injections than the other accessory organs; and that the length of the clitoris‐like organ is not normally determined by the presence of œstrogens.

The effects observed appear to be directly dependent upon the duration of the treatment.

The Oophorectomrised Guinea‐pig.

Solid testosterone implantations, of which 15 mg. were absorbed in 30 days by two oophorectomised immature guinea‐pigs, were associated with an increase in body weight without fat deposits, and with hypertrophy of the uterus and clitoris, and the formation of horny styles on the latter.

A successful testicular graft was made in one animal, which received 200 rat units of gonadotrophic hormone in 10 days. After thirty days, there was uterine hypertrophy, but no increase in body weight or in the length of the clitoris.

The oophorectomised controls showed a considerable increase in body weight and fat deposits. There was slight uterine regression, but the clitoris maintained its length.

It appears that the uterus is equally sensitive to testosterone and testis grafts. The clitoris is sensitive to testosterone, but probably requires a greater length of time to react to testicular material. This may account for the externally feminine appearance of naturally occurring mammalian intersexes, which are entirely lacking in ovarian tissue.
RENAL ARTERY LOOP IN THE DOG
Authors: Lockett M. F. , O'Connor W. J. , Verney E. B.
Published: December 2014

A method is described whereby the renal artery in the dog is enclosed in a loop of skin, and the blood‐supply to the kidney thereby brought under immediate external control.

Grateful acknowledgement is made to the Government Grant Committee of the Royal Society for defraying part of the expense incurred in this work.
METABOLISM OF LIVER SLICES AFTER BURNING
Authors: Clark E. J. , Rossiter R. J.
Published: December 2014

1. Anæsthetised rabbits burnt at 70°C. for ½ minute (area of burn ⅓ body surface) show a rise in red blood cell count within 2‐4 hours, which has fallen to normal by 24 hours.

2. There is no change in the ability of the liver to oxidise alanine or sodium butyrate either 4 or 24 hours after burning; there is also no change in the QGO2 and Qo2 measured in bicarbonate buffer.

3. After 4 hours there is a fall in the R. Q. (measured in phosphate buffer), rise in the QGN2, and fall in the ability of the liver to form glycogen from glucose; these have all returned to normal within 24 hours.

4. After 24 hours there is a slight rise in the Qo2 measured in phosphate buffer, which is not observed after 4 hours.

5. Implications of these results are discussed and it is concluded that they are in all probability secondary to the circulatory changes following the burn.

Thanks are due to Dr. J. M. Barnes for advice and information on the method of burning the animals, and to Miss J. Jenkins for valuable technical assistance.

One of us (E. J. C.) is indebted to the Medical Research Council for a personal grant and one (R. J. R.) to the Carnegie Trustees. The Medical Research Council has also contributed to the cost of this Research, which was carried out on behalf of the Burns Sub‐committee of the War Wounds Committee.
THE INFLUENCE OF METABOLIC STIMULANTS ON WOUND HEALING; THE INFLUENCE OF THYROID and 2‐4‐α DINITROPHENOL
Authors: Barclay T. H. C. , Cuthbertson D. P. , Isaacs A.
Published: December 2014

1. Dried thyroid gland, when fed to young adult male albino rats throughout the period of healing of circular skin wounds, caused a significant reduction in the mean time required for healing (11 per cent. reduction). When the rats were, in addition, given a pre‐period of thyroid feeding before operation, the mean time required for healing was reduced by 12 and 22 per cent. in the two experiments performed.

2. 2‐4‐α dinitrophenol fed as a component of the diet (0·012 per cent.) also caused a significant reduction in the mean time required for healing (15 to 27 per cent. reduction). Larger doses (0·09 per cent.) lacked this stimulant effect and the weight loss was marked.

3. The significance of these findings is discussed. It is not considered wise to attempt to influence the rate of normally healing wounds of patients by such stimulants.

In conclusion, we wish to thank Dr. E. Lewis‐Faning and Dr. P. L. McKinlay for their assistance in the statistical treatment of this investigation. We are also greatly indebted to the Medical Research Council, and to the Rankin Medical Research Fund of the University of Glasgow, for grants in aid of this work.
THE EFFECT OF INCREASED ACTIVITY OF THE SYMPATHETIC SYSTEM IN THE INHIBITION OF WATER‐DIURESIS BY EMOTIONAL STRESS
Authors: O'Connor W. J. , Verney E. B.
Published: December 2014

1. Tests of the effect of emotional stress produced by 30‐60 seconds faradic stimulation during water‐diuresis in normal dogs have revealed two types of inhibition of urine flow: a rapid inhibition which is abolished by section of the splanchnics and denervation of the kidneys and suprarenal (“denervation”), and a slow inhibition due to release of antidiuretic substance from the posterior lobe of the pituitary.

2. In 21 normal bitches, 3 gave large slow inhibitions in all tests, 7 always gave rapid inhibitions only, and 11 gave a large slow inhibition in some tests. After “denervation” a large slow inhibition was found in all tests in all animals.

3. The slow inhibition thus revealed could be prevented by the injection of adrenaline just before the application of the faradic stimulus.

4. Adrenaline did not diminish the inhibition produced by the injection of post‐pituitary extract.

5. It was concluded therefore, that after an injection of adrenaline, the resultant absence of the large slow inhibition produced by emotional srtess in the “denervated” animal was due to failure of release of the antidiuretic substance, and not to failure of the released substance to act on the kidney.

6. The irregular appearance of the slow inhibition in normal dogs is thus explicable in terms of failure of the release of antidiuretic substance from the posterior lobe owing to increased sympathetic activity during emotional stress.

7. Evidence has not yet been sought to determine the relative rôles of adrenaline and the renal nerves in the rapid type of inhibition, nor to decide whether the prevention of release of the antidiuretic hormone is due to adrenaline specifically or to an increase in arterial pressure.
ALVEOLAR OXYGEN TENSION AND LUNG CIRCULATION
Authors: Dirken M. N. J. , Heemstra H.
Published: December 2014

By means of a trachea divider the left and the right lung of the rabbit may be made to breathe gases of different oxygen content. If one lung is given a gas of low and the other one of high oxygen content, the saturation or the oxygen tension of the mixed arterial blood in the carotid artery depends on the mixing ratio of the blood from both lungs.

On switching one lung over to a gas of low oxygen content, the initial fall in saturation and in oxygen tension of the mixed arterial blood becomes spontaneously compensated to a major degree in about 8 hours.

Evidence is produced that this reaction results from a gradual increase in circulatory resistance of the hypoxic lung caused by a local action of the low oxygen tension. This conclusion is supported by the results of the measurement of the alveolar gas percentages in the rabbit.

To exclude an indirect action on the lung circulation caused by the effects of general hypoxæmia the influence of only slightly subnormal alveolar oxygen tensions was studied. Under these conditions the mixed arterial blood remained fully saturated. To this end a polarographic method was devised for measuring the oxygen tension of the blood.

Even at an alveolar oxygen percentage of approximately 12 per cent., which might normally be present in subventilated parts of the lungs, a distinct reaction occurs.

The increased vascular resistance may be abolished in about 4‐5 hours by restoring the normal alveolar oxygen tension.
SOME OBSERVATIONS ON THE BRONCHOCONSTRICTOR EFFECTS OF TUBOCURARINE
Authors: Maefouz M.
Published: December 2014

A rapid intravenous injection of tubocurarine usually causes broncho‐constriction in guinea‐pigs. A second injection has no such effect. The effect may be prevented or interrupted by neoantergan, and is probably due to the release of histamine. The best way to avoid this effect in the clinical use of tubocurarine is to give the injection slowly. Slow injections of large doses in guinea‐pigs had no effect on the bronchi, although a dose 10–15 times smaller caused bronchoconstriction when given rapidly.
OBSERVATIONS UPON A CHANGE IN AN ENZYMATIC PROCESS IN BURNS
Authors: Van Bekkum D. W. , Peters R. A.
Published: December 2014

1. A significant difference in the rate of deamination of DL‐alanine by liver slices of rats has been found between unburned and burned animals at the height of the nitrogen loss in the urine. Deaminating power was determined by estimation of the (NH3 + urea) N formed.

2. The experiments presented suggest this difference to be of an enzymatic nature.

3. In the course of the work it was found that deamination of DL‐alanine by liver slices was not influenced by the addition of glucose in vitro. Neither did a 24‐hour fast with its consequent depletion of glycogen influence the deaminating activity of the liver in vitro.

4. The significance of the decreased deamination in burned animals' liver slices is discussed; it appears to be the first enzymatic change to be correlated with the loss of N in the urine.
EXPERIMENTS ON THE HORSE STOMACH
Authors: Alexander Frank
Published: December 2014

1. Strips of muscle from the saccus cæcus of the horse's stomach showed slow contractions, and strips from the pyloric part faster con‐tractions. Both were inhibited by adrenaline and stimulated with acetylcholine.

2. The excised stomach showed only feeble contractions even when perfused with blood.

3. Records of stomach contractions in the unanæsthetized horse were secured by using stomach tubes of narrow diameter.

4. Introducing a wide diameter stomach tube into the œsophagus inhibited stomach contractions.

5. Feeding induced contractions, and fasting for 12‐24 hours caused them to stop or become intermittent. Intermittent contractions were not inhibited by feeding.

6. Stomach contractions were inhibited by adrenaline and atropine. Histamine, carbaminoylcholine and posterior pituitary extract had little action on the actively contracting or on the quiescent stomach.
The renal response to electrical stimulation of renal efferent sympathetic nerves in the anaesthetized greyhound.
Authors: Poucher S M , Karim F
Published: December 2014

1. The effect of direct electrical stimulation of the renal efferent nerves upon renal haemodynamics and function was studied in greyhounds anaesthetized with chloralose and artificially ventilated. The left kidney was neurally and vascularly isolated, and perfused with blood from one of the femoral arteries at a constant pressure of 99 +/‐ 1 mmHg. Renal blood flow was measured with a cannulating electromagnetic flow probe placed in the perfusion circuit, glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and solute excretion by osmometry. Beta‐Adrenergic receptor activation was blocked by the infusion of dl‐propranolol (17 micrograms kg‐1 min‐1). The peripheral ends of the ligated renal nerves were stimulated at 0.5, 1.0, 1.5 and 2.0 Hz. 2. At 0.5 Hz frequency only osmolar excretion was significantly reduced (10.3 +/‐ 3.2%, P less than 0.05, n = 6). Reductions in sodium excretion (53.6 +/‐ 8.5%, P less than 0.01, n = 6) and water excretion (26.9 +/‐ 8.0%, P less than 0.05, n = 6) and further reductions of osmolar excretion (20.7 +/‐ 3.7%, P less than 0.01, n = 6) were observed at 1.0 Hz; however, these were observed in the absence of significant changes in renal blood flow and glomerular filtration rate. Significant reductions were observed in glomerular filtration rate at 1.5 Hz (16.3 +/‐ 4.1%, P less than 0.02, n = 5) and in renal blood flow at 2.0 Hz (13.1 +/‐ 4.0%, P less than 0.05, n = 5). Further reductions in urine flow and sodium excretion were also observed at these higher frequencies. 3. These results clearly show that significant changes in renal tubular function can occur in the absence of changes in renal blood flow and glomerular filtration rate when the renal nerves are stimulated electrically from a zero baseline activity up to a frequency of 1.5 Hz. Higher frequencies caused significant changes in both renal haemodynamics and function.
Metabolic and contractile uniformity of isolated motor unit fibres of snake muscle.
Authors: Nemeth P M , Rosser B W , Wilkinson R S
Published: December 2014

1. Motor units in the thin transversus abdominis muscle of the garter snake were identified and physiologically characterized in the living state. Motor unit fibres, and fibres chosen randomly to serve as controls, were subsequently excised and subjected to biochemical analyses. 2. The metabolic capacity of fibres was assessed by measuring activities of three enzymes, each representing a different metabolic pathway. The microchemical enzyme assays were performed using enzyme extraction preparations of whole single fibres. 3. Metabolic capacity ranged widely among the muscle's entire fibre population, even among fibres of the same type. In contrast, enzyme activities of twitch fibres belonging to individual motor units were, within analytical error, identical. 4. Twitch contraction times of individual fibres within one motor unit were similar, compared to a wide range of contraction times observed among fibres of the same type but belonging to different motor units. 5. When several motor units were studied in one muscle, a systematic relationship was observed among motor unit tension, enzymatic profile and contraction time. As motor unit tension increased, fibres exhibited greater capacities for glycolytic and high‐energy phosphate metabolism, diminished capacity for oxidative metabolism, and faster twitch contraction times. 6. Given the great diversity of metabolic and contractile properties exhibited within the fibre population, the uniformity of such properties within motor units indicates that neural influence dominates over other extrinsic factors present in the microenvironment of the muscle fibres.
Voltage clamp measurements of the hyperpolarization‐activated inward current I(f) in single cells from rabbit sino‐atrial node.
Authors: van Ginneken A C , Giles W
Published: December 2014

1. The kinetics and ion transfer characteristics of the hyperpolarization‐activated inward current, I(f), have been studied in single cells obtained by enzymatic dispersion from the rabbit sino‐atrial (S‐A) node. These experiments were done to assess the role of I(f) in the generation of the pacemaker depolarization in the S‐A node. 2. The activation and the deactivation of I(f) in these single cells are accompanied by significant conductance increases and decreases respectively, confirming earlier findings from multicellular man‐made strips of rabbit S‐A node, and from mammalian Purkinje fibres. 3. The steady‐state activation of I(f) lies between ‐40 and ‐120 mV, and its voltage dependence can be described by a Boltzmann relation with the half‐activation point at approximately ‐70 mV. 4. The delay or sigmoidicity in both the onset of I(f) and the deactivation of the tail currents can be accounted for semi‐quantitatively by using a second‐order Hodgkin‐Huxley kinetic scheme. 5. The reversal potential for I(f) is ‐24 +/‐ 2 mV (mean +/‐ S.E.M., n = 6). It does not change significantly as a function of the amount of I(f) which is activated, indicating that ion accumulation or depletion phenomena are not important variables controlling the time course of I(f), or its selectivity. 6. The fully‐activated current‐voltage relationship for I(f) is approximately linear with a slope conductance of 12.0 +/‐ 0.88 nS per cell (mean +/‐ S.E.M., n = 6). 7. A simple mathematical model based on the measured values of maximum conductance, reversal potential, and kinetics of I(f) has been developed to simulate the size and time course of I(f) during typical spontaneous pacemaker activity in rabbit sino‐atrial node cells. The calculations show that I(f) can change significantly during pacing and suggest that this current change is, at least in part, responsible for the pacemaker depolarization.
Pattern of cutaneous inhibition of the propriospinal‐like excitation to human upper limb motoneurones.
Authors: Nielsen J , Pierrot‐Deseilligny E
Published: December 2014

1. The pattern of cutaneous inhibition of non‐monosynaptic excitation (or ‘propriospinal‐like’ excitation) to various species of motoneurones‐wrist flexors and extensors, biceps and deltoid ‐ was investigated in man. 2. Changes in the firing probability of individual voluntarily activated motor units were studied following various stimuli. The effects of weak cutaneous stimuli applied to the skin of either the palmar or the dorsal side of the fingers on propriospinal‐like excitation evoked by stimulation of different mixed nerves (median, radial, musculo‐cutaneous) were investigated. 3. Cutaneous stimuli were found to produce an inhibition with a very specific pattern, which depended on the afferent input evoking the excitation. Thus, the median nerve‐induced excitation of wrist and elbow flexors was depressed by cutaneous afferents from the palmar side but not from the dorsal side of the fingers; the radial nerve‐induced excitation of wrist extensors was only depressed from the dorsal side: the musculo‐cutaneous nerve‐induced excitation of motor units of various wrist, elbow and shoulder muscles was depressed from both sides. 4. It is argued that this pattern implies that the excitation is mediated to the motoneurones through different subsets of neurones, organized according to the afferent input. 5. The functional significance of the pattern of cutaneous inhibition is discussed and it is argued that it could contribute to an appropriately timed termination of a movement mediated through the propriospinal system.
Evidence for descending tonic inhibition specifically affecting sympathetic pathways to the kidney in rats.
Authors: Hayes K , Yardley C P , Weaver L C
Published: December 2014

1. The present study investigated the possibility that pre‐ and postganglionic neurones innervating the kidney and spleen in rats are affected by descending inhibitory as well as descending excitatory influences. This hypothesis was tested by comparing the effects of cervical spinal cord transection to the effects of blockade of tonic activity of excitatory neurones in the rostral ventrolateral medulla (RVLM). 2. Electrical discharge of multifibre postganglionic renal and splenic and preganglionic greater splanchnic nerves and 13th thoracic (T13) white rami was recorded in artificially respired, urethane‐anaesthetized rats. In one group of rats, descending supraspinal pathways were interrupted by cervical spinal cord transection. In another group, tonic activity of rostral ventrolateral medulla (RVLM) neurones was blocked by bilateral microinjections of the inhibitory amino acid glycine. The effects of spinal cord transection were compared to effects of this bilateral RVLM blockade and to effects of unilateral RVLM blockade described in a previous study. 3. Spinal cord transection caused decreases in preganglionic greater splanchnic and postganglionic splenic nerves which were of the same magnitude as those caused by bilateral blockade of the RVLM. 4. In contrast, discharge of renal nerves was decreased more by bilateral RVLM blockade than by cervical spinal cord transection. Similarly, even unilateral RVLM blockade caused greater decreases in discharge of T13 white rami than were caused by spinal cord transection. 5. These findings suggest that renal nerves and their preganglionic inputs (T13 white rami) are controlled in part by tonic sympathoinhibitory influences which can be unmasked by blockade of the RVLM. These sympathoinhibitory influences do not appear to affect the activity of splanchnic and splenic nerves.
The effect of static exercise on renal sympathetic nerve activity in conscious cats.
Authors: Matsukawa K , Mitchell J H , Wall P T , Wilson L B
Published: December 2014

1. Renal sympathetic nerve activity (RNA), heart rate (HR), arterial blood pressure (AP), and force development were measured simultaneously during voluntary static (isometric) exercise performed by conscious cats. The cats were operantly trained to press a bar with one forelimb. When the force applied to the bar exceeded a predetermined value (threshold), a sound was emitted by a buzzer for audio‐feedback. If the cat continued to produce the appropriate force for a period of 26‐55 s, food was given as a reward. 2. A total of eighty‐nine exercise trials were performed by seven cats. The peak force applied to the bar was 468 +/‐ 28 g (mean +/‐ S.E.M.). RNA, HR, and AP increased significantly from the control value during static exercise by 102 +/‐ 14%, 23 +/‐ 2 beats/min, and 11 +/‐ 1 mmHg, respectively. 3. The increase in RNA had both an initial and a late component. The initial component occurred at or immediately before the onset of force development and lasted for 10 s, while the late component gradually increased 14 s after the onset of static exercise and was sustained until the exercise was terminated. 4. HR also increased at the beginning of static exercise with a similar time course as RNA. Then, HR returned to the control value and remained at that level during the remainder of exercise. The increase in AP was delayed by 10 s from the initial increase in RNA and then continued to rise throughout the period of exercise. 5. The sound of the buzzer was emitted during rest to determine any influence of anticipation or conditioning on the response. RNA and AP increased slightly, but HR did not change. The increases in RNA and AP were much smaller than the increases obtained during static exercise. Thus, the increases in RNA, HR and AP during static exercise appeared to be associated with the exercise itself and not due to anticipation and/or conditioning. 6. When AP was elevated by a bolus injection of noradrenaline, RNA during rest was almost abolished and the increase of RNA during static exercise was markedly inhibited. Thus the arterial baroreflex significantly influences RNA both during rest and during static exercise. 7. This study suggests that the initial increases in RNA and HR at the beginning of static exercise in conscious cats are caused by descending input from higher brain centres and not by afferent feedback signals from muscle receptors or by arterial baroreceptors.(ABSTRACT TRUNCATED AT 400 WORDS)
The role of cutaneous afferents in the control of gamma‐motoneurones during locomotion in the decerebrate cat.
Authors: Murphy P R , Hammond G R
Published: December 2014

1. The effect of electrical stimulation, up to 20x threshold (T), of the sural nerve on the discharges of single medial gastrocnemius static and dynamic gamma‐motoneurones has been investigated at rest and during locomotion in the decerebrate cat. 2. A total of twenty‐three gamma‐motoneurones were recorded. The neurones were identified as static (15) or dynamic (8) on the basis of their discharge characteristics (Murphy, Stein & Taylor, 1984). 3. Low intensity stimulation (less than or equal to 1.5T) had no effect on the discharges of most (22 of 23) gamma‐efferents at rest or during locomotion. Hence the largest afferents in the sural nerve had little influence on the discharges of static or dynamic gamma‐motoneurones in either condition. 4. Higher intensity stimulation (greater than 1.5T) excited both types of gamma‐efferent in the resting state and response size was graded with stimulus intensity. For most neurones (20 of 23) excitatory effects appeared in the range 1.5‐2T. 5. Stimulation at intensities greater than 1.5T also excited dynamic and some static gamma‐motoneurones during locomotion. The responses of dynamic gamma‐motoneurones were unchanged during locomotion compared to the resting state. In contrast, the responses of static neurones were significantly reduced, or even abolished, during locomotion and stimuli less than or equal to 3T generally (12 of 13) had no effect. Thus the responses of static, but not dynamic, gamma‐efferents were task dependent. Further, the thresholds of responses indicate that activation of low threshold mechanoreceptors in the sural receptive field excites both types of gamma‐efferent at rest, and dynamic neurones during locomotion. In contrast, it is proposed that the same peripheral input does not affect static gamma‐efferents during locomotion. 6. The responses of static and dynamic gamma‐motoneurones during locomotion were not obviously related to step cycle phase, or gamma rate, and responses occurring during or between homonymous electromyogram (EMG) bursts were not significantly different. Thus gamma responses during locomotion were not phase dependent. 7. Stimulation at intensities greater than 3T excited dynamic and some static gamma‐motoneurones during locomotion but simultaneously inhibited on‐going EMG activity. Peripheral inputs are therefore capable of influencing alpha‐ and gamma‐motoneurones independently during locomotion. 8. The significance of the results is discussed in relation to the control and function of gamma‐motoneurones.