bluuebunny/crossref_metadata_2025 huggingface dataset:
CARBONIC ANHYDRASE ACTIVITY IN SALIVA IN MAN
Authors: Szabo I. , Mason D. K. , Harden R. McG.
Published: December 2014

The carbonic anhydrase activity has been measured in human parotid, submandibular and mixed saliva. In parotid saliva the activity was related to salivary flow rate, rising from less than 1·6 K/ml. at low flow rates to a maximum of about 2·2 K/ml. at higher rates of flow. The enzyme activity remained constant at flow rates greater than 0·8 ml./min. The concentration in submandibular saliva tended to be less than the concentration in parotid saliva. The enzyme activity in the blood was found to be 1·9 K/ml.

Enzyme activity was not affected by storage at 0° C., 370° C. and room temperature for up to 48 hr. Similar values were found when saliva was collected under oil and when saliva was collected without oil.
ULTRASTRUCTURAL CHANGES IN LYMPHOCYTES EXPOSED TO NOXIOUS AGENTS IN VITRO
Authors: Trowell O. A.
Published: December 2014

The cytopathological changes produced in lymphocytes by various noxious agents applied in vitro were studied under the electron microscope.

Four different lesions were found: (1) the ‘anoxic’ lesion, produced by anoxia or cyanide, characterized by gross watery swelling of all the cytoplasmic components and internal breakdown of the nucleus; (2) the lesion produced by SH poisons, characterized by swelling of the cytoplasmic matrix and destruction of the cell and nuclear membranes; (3) the ‘lytic’ lesion, produced by tear gases and chloroform, characterized by rapid onset of cytoplasmic lysis, and (4) the ‘radiomimetic’ lesion, produced by X‐rays, cortisone, mitotic poisons, barbiturates, and glucose deprivation, in which the most striking feature was an increased number of ribosomes.

The results suggest that radiation, cortisone, mitotic poisons and barbiturates kill lymphocytes by interfering with the uptake or early metabolism of glucose by the cells.
THE ORIGIN OF THE RIGHT AORTIC NERVE IN THE RABBIT
Authors: Green J. H. , Heffron P. F.
Published: December 2014

The right aortic nerve in the rabbit has been traced by dissection under the binocular microscope, and studied electroneurographically.

In the middle part of its course it becomes a mixed baroreceptor‐autonomic nerve as a result of contributions from the vagus and cervical sympathetic chain. It divides into two branches, a slender one going to the bifurcation of the brachiocephalic trunk, and a larger one passing into the thorax.

Electroneurographic studies indicate that the slender branch bears most of the baroreceptor activity found in the aortic nerve, and that the bifurcation of the brachio‐cephalic trunk is a baroreceptor area.

The larger branch appears to be a cardiac nerve bearing inter alia efferent sympathetic fibres, the activity of which can be reflexly inhibited by increased baroreceptor activity from the area described.
THE EFFECT OF BENZOTHIADIAZINE DIURETICS ON THE RENAL CONCENTRATING MECHANISM OF THE SHEEP
Authors: Cross R. B. , Thornton W. M.
Published: December 2014

The effects of an infusion of vasopressin (40 m. U. I. V.) were studied in conscious sheep. Vasopressin caused consistent increases in urinary total solute and K output and variable increases in Na and Cl excretion. Vasopressin always increased water reabsorption relative to solute reabsorption, although an antidiuresis did not occur when the initial urine concentration exceeded 1000 µ osmoles/mnl.

Prior administration of therapeutic doses of diuretic or anti‐hypertensive drugs of the benzothiadiazine group modified the action of vasopressin. Water reabsorption relative to solute reabsorption was still increased, but vasopressin no longer produced increases in total solute output. The increases in K and Cl excretion were significantly smaller than those seen in the untreated animals.
HEAD'S PARADOXICAL REFLEX
Authors: Widdicombe J. G.
Published: December 2014

Cold block of the vagus nerves of rabbits completely prevents conduction in pulmonary stretch fibres at temperatures close to or higher than those required to block the Hering‐Breuer inflation reflex. These temperatures are several degrees higher than those required to block Head's paradoxical reflex. It is concluded that Head's paradoxical reflex cannot be due to pulmonary stretch fibre activity during cold block; that is, cannot be due to cold block of the vagus nerves being more effective for high‐frequency discharges (during lung inflation) than for low‐frequency discharges in pulmonary stretch fibres. This conclusion is supported by a consideration of the pattern of Head's paradoxical reflex, and by a summary of the published evidence that the reflex can be elicited when the nerves are not being cooled at all.
THE ABSORPTION OF MICELLAR LIPID INTO THE LYMPH OF UNANAESTHETISED RATS
Authors: Redgrave T. G.
Published: December 2014

The lymphatic output of fat in unanæsthetised rats during and after 8 hr. steady infusion of micellar lipid into the duodenum was compared with the outputs for emulsions of oleic acid and olive oil infused at the same dose level. The results were consistent with the view that micellar solutions represent the final common pathway for presentation of lipid to the mucosal cells for absorption. The histological appearances of the mucosal cells during steady absorption of micellar lipid were identical with the appearances during absorption of emulsified lipid at the same rate. There was evidence of an increased output of nonߚdietary fat in the lymph during fat absorption.
ACETYLCHOLINE SYNTHESIS IN REINNERVATED SALIVARY GLANDS
Authors: Nordenfelt Ivar , Perec Carlos
Published: December 2014

The synthesis of acetylcholine and the sensitivity towards sialagogue agents were studied in the submaxillary gland of the cat after crushing the preganglionic parasympathetic fibres and in the parotid gland of the rabbit after crushing the postganglionic parasympathetic fibres. The first signs of reinnervation in the cat's submaxillary gland were found after about two months, as seen by a decrease of supersensitivity and a slight increase in choline acetylase activity. Complete reinnervation varied very much but seemed to occur within a year. Reinnervation of the postganglionically denervated rabbit parotid gland was slower and much less complete.
THE EFFECT OF INTRAVENOUSLY INFUSED SALINE ON THE RENAL CLEARANCES OF INULIN AND PARA‐AMINOHIPPURATE IN DOGS
Authors: Ramsay D. J. , Coxon R. V.
Published: December 2014

Inulin and para‐aminohippurate clearances were measured both by the continuous infusion and subcutaneous injection methods in a group of seven dogs. The mean and standard deviations for the inulin clearances were 4·19±0·41 and 3·33±0·59 ml./min./kg. and for para‐aminohippurate clearances were 14·57±2·45 and 11·98±2·46 ml./min./kg. for the infusion and injection methods respectively, the injection values being significantly lower than the infusion values. Simultaneous infusion of normal saline increased the values in injection experiments to those found in the infusion series. It is concluded that infusion of saline increases the values measured for inulin and para‐aminohippurate clearances, and that the subcutaneous injection method may provide a truer estimate of these clearances.
THE INSULATIVE VALUE OF MOUSE FUR
Authors: Dawson N. J. , Webster M. E. D.
Published: December 2014

Work reported in the literature has demonstrated the importance of physical insulation as a factor affecting the metabolic response of animals to thermal loads. This paper describes a technique for measuring the thermal insulation of the fur on small pelt samples. The insulation of the fur of the mouse (Mus musculus) was 0·20 (S.D. = 0·04) clo or 1·55 (S.D. = 0·46) clo/cm. Special problems relating to the value of the insulation of the fur to small animals such as mice are discussed.
RELEASE OF AN ESTERASE FROM LIVER UPON HEPARIN INJECTION
Authors: de Meis Leopoldo , Maroja Renato
Published: December 2014

Evidence is presented that heparin induces the release of an esterase (HE) from liver. Several organs were perfused with in vitro heparinized blood (500 to 800 I.U. per cent). Esterase activity was measured manometrically in a Warburg apparatus. HE was differentiated from the pseudocholinesterase normally found in plasma by its resistance to prostigmine. The CF activity was measured by the decrease of plasma turbidity in the presence of dog chyle. Attempts were made to differenciate HE from the ‘clearing factor’ (CF).

Hind limb and heart‐lung perfusions with in vitro heparinized blood, caused the release of CF into the perfusion medium, but no HE activity was found. Perfusion of the liver with in vitro heparinized blood released HE and CF. Maximum HE activity was obtained following two to four minutes of perfusion. The presence of heparin was required for the release of HE, since perfusion with citrated blood did not release the enzyme.

Liver perfusion with a suspension of red cells in saline‐glucose‐heparin solution (SPH) released HE, but no CF activity was found. Perfusion with a similar mixture without heparin did not release HE. Extracts of heart powder with in vitro heparinized plasma only showed CF activity. HE is strongly inhibited by protamine sulphate and is capable of hydrolyzing several low molecular weight esters.
SOME EFFECTS OF MATERNAL HYPEROXIA AND HYPOXIA ON THE BLOOD GAS TENSIONS AND VASCULAR PRESSURES IN THE FOETAL SHEEP
Authors: Parker H. R. , Purves M. J.
Published: December 2014

Blood gas tensions, pH and intravascular pressures have been measured at various sites in 22 foetal sheep of gestational age 110–147 days. Umbilical venous oxygen tension did not change significantly with age. The mean pulmonary artery pressure always exceeded that in the aorta and this pressure gradient did not change with age. By contrast the umbilical arterio‐venous pressure gradient increased with age. When the ewe breathed room air, the oxygen difference between uterine artery and umbilical vein was 43–62 mm. Hg. When the ewe breathed 100 per cent 02 umbilical venous P02 rose by 4–15 mm. Hg and umbilical venous pH fell by 0·04–0·07 pH units. There were no consistent changes in foetal heart rate or blood pressures.

When the ewe breathed 10 per cent O2 in N2, umbilical venous P02. fell by 7–14 mm. Hg, mean pressures in pulmonary artery and aorta and the pulmonary artery/aortic pressure gradient increased as did the size of the right to left shunt across the ductus arteriosus. Heart rate invariably increased. The oxygen saturation difference between ascending and descending aorta was maintained or increased.

These results suggest (1) that factors other than a diffusion barrier to oxygen are responsible for the maternal/foetal oxygen gradient and (2) that, with maternal hypoxia, there is a redistribution of blood flow in the foetus so that as high a tissue P02 as possible is maintained in coronary and cerebral circulations.
INFLUENCE OF INCREASING HEART RATE ON THE ALTERATIONS OF THE CARDIAC VENTRICULAR FIBRE‐CELLS ACTION POTENTIALS INDUCED BY THIAMINE DEFICIENCY
Authors: Rapuzzi G. , Rindi G.
Published: December 2014

In rats, the action potentials of myocardial fibre‐cells in avitaminosis B1, induced by a deficient diet or by pyrithiamine administration, were measured by fluctuating microelectrodes on hearts in situ at spontaneous and at externally increased heart rate. The increasing of the heart rate enhanced the modifications of the action potentials of spontaneously beating thiamine‐deficient hearts. This suggests that the increased rate may determine a reduction in ion gradients on both sides of the cell membrane.

The slowed spontaneous heart rate of thiamine‐deficient rats seems to allow full recovery of the membrane ionic distribution, even if the underlying ion processes were greatly reduced.
THE DIFFERENTIATION OF CONDUCTION VELOCITIES OF SLOW TWITCH AND FAST TWITCH MUSCLE MOTOR INNERVATIONS IN KITTENS AND CATS
Authors: Ridge R. M. A. P.
Published: December 2014

The difference in conduction velocity (maximum and mean) of the α motor nerve fibres to fast (flexor hallucis longus) and slow (soleus) twitch muscles in adult cats has been verified, and qualitatively similar differences found in adult rabbits and rats. In addition the conduction velocities of α motor nerve fibres to flexor digitorum longus, gastrocnemius medialis and tibialis anticus muscles have been measured in adult cats.

Similar measurements (F.H.L. and soleus only), have been made in a series of kittens ranging in age from 8 hr. to 56 days. Although the conduction velocities in the new‐born kitten are one‐tenth those of the adult, the ratio of the conduction velocities of α motor nerve fibres to fast and slow muscles remains approximately constant from birth onwards.

It is concluded that at birth the differentiation of the conduction velocities of the α motor nerve fibres to muscles destined to become fast and slow twitch muscles is complete, although at this time the muscles themselves are only beginning to differentiate in terms of contraction times.
THE EFFECTS OF POTASSIUM SUPPLEMENTS UPON THE ABSORPTION OF POTASSIUM AND SODIUM FROM THE SHEEP RUMEN
Authors: Scott D.
Published: December 2014

The infusion of potassium salts into the rumen of sheep led to an increase in both the concentration and amount of potassium in the fluid in the rumen and to a decrease in the concentration and amount of sodium. The amount of potassium absorbed from the rumen increased as the intake of potassium was increased and was related to the concentration of potassium in the rumen fluid. The amount of potassium flowing out of the rumen increased and the amount of sodium flowing out decreased with increase in potassium intake but neither the volume of fluid in the rumen nor the rate at which it flowed on to the omasum was affected. There was no evidence that potassium supplements reduced the amount of sodium entering the rumen in the saliva. These results indicate that the amount of sodium absorbed from the rumen is increased when potassium supplements are given.
GLYCOGEN METABOLISM IN RABBIT KIDNEY UNDER DIFFERING PHYSIOLOGICAL STATES
Authors: Darnton S. Jane
Published: December 2014

Glycogen, has been assayed biochemically and histochemically in the kidney medulla. It is distributed very discretely in the epithelial cells of the collecting ducts of the papilla.

Histochemical and biochemical methods showed that glycogen levels are doubled in diuresis produced by administration of a water‐load or mannitol. In antidiuresis, produced by dehydration or administration of deoxycorticosterone acetate, the glycogen levels are halved as compared with control kidney papillæ. The interstitial mucopolysaccharide structure of the papilla appeared thickened in antidiuresis and was œdematous in diuresis, when compared with sections taken from control kidneys.

The glycogen content of the two kidneys of a single animal was not the same. Rabbit kidneys seemed to show a summing action, not working as a pair in parallel but giving a total response appropriate to the water balance of the whole animal.

It is suggested that the glycogen could be involved in the provision of energy for active transport processes involved in the transport of ions from the lumen of the collecting ducts to the papillary interstitium or alternatively, or in addition, could also act as a precursor for mucopolysaccharides of the papillary interstitium.
CHOLINESTERASE IN THE SUBMAXILLARY GLAND OF THE RAT AFTER SYMPATHETIC DENERVATION
Authors: Nordenfelt Ivar
Published: December 2014

Cholinesterase activities have been estimated manometrically in submaxillary glands of the rat after postganglionic sympathetic denervation.

In denervated glands there is a significant increase of the break down of the two substrates studied, methacholine chloride and benzoylcholine chloride. This finding is considered to support the hypothesis that in the glands there is collateral sprouting of cholinergic fibres after degeneration of adjacent sympathetic neurones.
A METHOD FOR THE ESTIMATION OF THE UMBILICAL BLOOD FLOW IN UNSTRESSED SHEEP AND GOATS WITH SOME RESULTS OF ITS APPLICATION
Authors: Crenshaw C. , Curet L. B. , Mannn L. , Barron D. H. , Huckabee W. E.
Published: December 2014

Experiments were carried out to test the applicability of the ‘diffusion equilibrium’ technique to the estimation of the rate of umbilical blood flow in unstressed ewes and does (female goats) in the last third of gestation. Antipyrine was infused into the maternal circulation for 5–7 min. whilst the concentration difference across the umbilical circuit was followed for 30 min. during which it rose and then fell to insignificance. A comparison of the concentrations of antipyrine in umbilical blood and fetal tissue at the 30th min. indicated such a degree of agreement that blood concentration can be substituted for tissue concentration as the numerator in the equation expressing the Fick principle. Results of the application of the method in both acute and chronic experiments are presented, together with data on the v‐a oxygen difference across the umbilical circuit and the oxygen consumption of the fetus in utero.
THE INDUCTION OF OVULATION IN IMMATURE RATS TREATED WITH PREGNANT MARE'S SERUM GONADOTROPHIN AND HUMAN CHORIONIC GONADOTROPHIN
Authors: Lunn S. F. , Bell E. T.
Published: December 2014

Studies have been made on ovarian and uterine weight, the occurrence of follicular hæmorrhage and ovulation, and the number of ova shed in the intact immature rat treated with pregnant mare's serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) either alone or in combination.

Both PMSG and HCG when given alone were capable of inducing ovulation. This event was associated with uterine stimulation but generally occurred in the absence of marked ovarian weight increase or follicular hæmorrhage.

The administration of PMSG followed by HCG produced ovulation over a wide dosage range of both hormones. With low dose levels of PMSG the number of ova shed was independent of the dosage of HCG. However, this was not the case at higher dosages of PMSG, the injection of which was associated with marked ovarian weight increase and follicular hæmorrhage.

The mechanism by which PMSG and HCG exert their effects on the ovary is discussed.
LITTER SIZE AND THE DURATION OF PREGNANCY IN MICE
Authors: Dewar A. D.
Published: December 2014

Analysis of the data from 1246 dated mouse pregnancies revealed an inverse relationship between litter size and gestation period which, however, was not continuously linear over the range of litter sizes as previously shown [Biggers et al., 1963], but was mostly evident as an increase in mean duration with litters below modal size. An additional cause of this effect is suggested.

The effect on pregnancy of the administration of œstradiol in amounts likely to cover the ‘physiological’ range was investigated. No reduction in gestation period was observed; with the higher doses, pregnancy was significantly prolonged. The findings do not support the hypothesis that the litter size — gestation period effect involves placental œstrogen.
THE EFFECT OF CÆSIUM IONS ON NEUROMUSCULAR TRANSMISSION IN THE FROG
Authors: Ginsborg B. L. , Hamilton J. T.
Published: December 2014

The effect of Cs+ on neuromuscutlar transmission in the frog has been investigated. In both K+‐containing and K+‐free solutions, the presence of Cs+ allowed a gradual increase in the amplitude of the evoked end‐plate potential (e.p.p.) which was due to an increase in the output of transmitter. However, after prolonged exposure to Cs+ in K+‐free solutions, the duration of the e.p.p. was increased and its amplitude progressively reduced, eventually to zero. The effects of Cs+ were reversible. The results are consistent with the idea that exposure to Cs+ ions allows their entry into nerve terminals in exchange for K+ ions, thereby resulting in an increased duration of the projunctional action potential.
AN ATYPICAL ACTION OF ACETYLCHOLINE ON THE STRIPED MUSCLE OF THE GUINEA‐PIG ŒSOPHAGUS
Authors: Bartlet A. L.
Published: December 2014

Acetylcholine produced a longitudinal contraction of the separated externa of the guinea‐pig œsophagus, which was blocked by cocaine or tubocurarine and was partially antagonized by hexamethonium or hyoscine. Acetyl‐β‐methylcholine was almost without action on this preparation.

On the whole œsophagus, acetylcholine produced a biphasic contraction which was blocked by cocaine and was partially antagonized by hexamethonium. The fast component of the contraction to acetylcholine was blocked by tubocurarine and was partially antagonized by hyoscine, and the slow component of the contraetion to acetylcholine was blocked by hyoscine and was partially antagonized by tubocurarine. Acetyl‐β‐methylcholine produced a monophasic contraction which was blocked by hyoscine and was potentiated by cocaine.
THE EFFECT OF A PROTEIN MEAL WITH AND WITHOUT SUBSEQUENT EXERCISE ON PLASMA INSULIN AND GROWTH HORMONE
Authors: Sukkar M. Y. , Hunter W. M. , Passmore R.
Published: December 2014

Plasma levels of insulin and growth hormone have been measured over a 6‐hr. period in ten normal subjects, (a) fasting and resting, (b) after a protein meal and resting, and (c) after a protein meal followed by 2 hr. moderate exercise. Low levels of insulin and growth hormone were found during fasting and the insulin levels fell further throughout the fast. After ingestion of protein, plasma insulin and growth hormone concentrations increased; the rise in insulin secretion preceded the rise in growth hormone. Moderate muscular exercise in the absorptive phase of the meal abolished or markedly diminished the insulin response to protein and enhanced the growth hormone response. It is concluded that dietary protein may have a role in the physiological regulation of insulin and growth hormone release. The metabolic implications of these findings are discussed in terms of the requirements of energy metabolism.
THE EFFECT OF POSTERIOR PITUITARY HORMONES ON THE CALCIUM, MAGNESIUM, PHOSPHATE AND CHLORIDE METABOLISM OF SHEEP
Authors: Moodie E. W.
Published: December 2014

The effect of posterior pituitary hormones on the calcium, magnesium, inorganic phosphate and chloride metabolism of five female sheep was studied. Each sheep was subjected to a control observation and to intravenous injections of 450 mU per minute for 30 min. of each of the following: oxytocin (both with and without pretreatment with 5 mg. diethylstilboestrol subcutaneously), pituitary (posterior lobe) extract and vasopressin. Changes in arterial blood concentrations and in absorption from the digestive tract of calcium, magnesium, inorganic phosphate and chloride were estimated.

Oxytocin markedly reduced the arterial concentrations of inorganic phosphate and probably increased the absorption of calcium. Vasopressin temporarily increased the arterial blood inorganic phosphate concentration and probably reduced calcium absorption. No effect was observed on the magnesium and chloride metabolism of the sheep as a result of any treatment. The results are discussed in relation to milk fever (parturient hypocalcæmia) in cattle.
THE EFFECT OF REPETITION ON MEASUREMENTS OF POST‐ROTATIONAL TURNING SENSATION AND NYSTAGMUS IN MAN
Authors: Brand J. J.
Published: December 2014

The effects of repetition on the post‐rotational turning sensation and nystagmus obtained after deceleration from constant angular velocities are described. In a first series of tests decelerative stimuli from constant angular velocities of 60, 30, 15 and 7·5°/sec. were given to two groups of subjects but in a different order, and the mean responses obtained from both groups showed that habituation might occur in the course of a single test.

In a second series with a different group of subjects, the test was repeated on each of nine consecutive days. The effects of habituation were again seen and there was a progressive decline in the responses which were obtained. The administration of l‐hyoscine ( 0·7 mg. base) 1 hr. before the test on the sixth day produced little additional effect in habituated subjects.
EFFECT OF ISOXSUPRINE HYDROCHLORIDE ON THE SURVIVAL RATE OF DOGS SUBJECTED TO ACUTE BLOOD LOSS
Authors: Sharma P. L.
Published: December 2014

In dogs anæsthetized with pentobarbitone sodium, hæmorrhagic shock was produced by rapid bleeding. The blood pressure was maintained at 35 ± 5 mm. Hg for 4 hr., and then the shed blood was returned to the animal. Animals alive at the end of a 72‐hr. observation period were considered as survivors. In the control group only one out of ten dogs survived. All the animals developed severe watery diarrhœa Isoxsuprine hydrochloride 0·3 mg./kg. administered intravenously in 10 ml./kg. of normal saline 2 hr. after the onset of oligæmic hypotension increased the survival rate from 1/10 in the control group to 7/10 in the treated group. Only two dogs developed mild diarrhœa. The incidence of ventricular arrhythmias during fluid replacement was reduced from 7/10 to 2/10. However, when this drug was administered 4 hr. after the onset of oligæmic hypotension there was no improvement in the survival rate as compared to the control group but death was significantly delayed in the treated cases. The incidence of ventricular arrhythmias was reduced from 7/10 to 4/10. All the animals developed severe watery diarrhœa.

The beneficial effect of isoxsuprine may be due to improved tissue perfusion resulting from vasodilatation and an increase in the volume of circulating fluids produced by the concomitant infusion of normal saline to sustain the blood pressure above 30 mm.Hg. Another factor might be the positive inotropic action of this drug.

It is suggested that isoxsuprine may prove useful in the management of oligæmic shock in man.
THE EFFECT OF DIETARY FAT LOAD ON THE SIZE AND COMPOSITION OF CHYLOMICRONS IN THORACIC DUCT LYMPH
Authors: Fraser R. , Cliff W. J. , Courtice F. C.
Published: December 2014

Chylomicrons of Sf 〉 400 and lipoproteins of Sf 12‐400 were separated by ultra‐centrifugation from samples of thoracic duct lymph collected from rabbits fed for 1 to 2 weeks previously on diets containing 5 per cent and 30 per cent corn oil or butter and from rats given a single intragastric dose of 0·5 ml. corn oil.

The size of these particles after corn oil was determined by electron microscopy following fixation in osmium tetroxide. In rabbits on the low fat diet the mean diameter of chylomicrons was 960 Å with half the triglyceride in particles of diameter greater than 1400 Å; on the high fat diet the mean diameter was 1435 Å with half the triglyceride in particles of diameter greater than 2700 Å. In rats the mean chylomicron diameter was 1094 Å in the early phase of fat absorption with half the triglyceride in particles of diameter greater than 1320 Å. These figures increased to 2105 Å and 3600 Å respectively at the peak of fat absorption.

The relationship between the chemical composition of these complexes and their actual size suggests that phospholipid is uniformly distributed on the surface, each phospholipid molecule occupying approximately 65 Å2.

Although meaningful electron micrographs of butter chylomicrons could not be obtained, determinations of the triglyceride : phospholipid ratios indicate that, as with the corn oil‐fed animals, the chylomicrons from the rabbits fed 30 per cent butter are on the average larger than those from the animals fed 5 per cent butter.
LYMPH FLOW AND PROTEIN COMPOSITION OF THORACIC DUCT LYMPH IN THE NEWBORN CALF
Authors: Shannon A. D. , Lascelles A. K.
Published: December 2014

The changes in the flow and protein composition of thoracic duct lymph have been studied in unanæsthetized calves during the first 6 days after birth. Thoracic duct‐venous shunts were established in four calves (average body weight 35·2 kg.) within 3 hr. of birth. The calves recovered quickly from the operation and were able to suck strongly within 1–2 hr. of its completion. Lymph flow during anæsthesia varied between 90–150 ml./hr. and by 1–2 hr. after the operation, immediately before first feeding, flow had risen to values of 300–450 ml./hr. There was a marked increase in flow and globulin concentration during the 8–hr. period after the first feeding, peak values observed being 850 ml./hr. and 2·72 g. per cent, respectively. Fractionation of colostral whey and lymph on G‐200 and DEAE Sephadex columns indicated that the increase in globulin in the lymph was due to the absorption of γ1‐globulin which is present in high concentration in colostrum. Subsequently, flow and protein content decreased quite rapidly and by 24 hr. after first feeding the values were relatively constant. The results suggested that the absorption of γ‐globulin had virtually ceased by 24 hr. There was a slower decrease in lymph flow and globulin content over the subsequent 4–6 days.
AUGMENTED RENAL EXCRETION OF CALCIUM AND MAGNESIUM IN SHEEP AFTER FEEDING
Authors: Stacy B. D.
Published: December 2014

When penned sheep were given their daily food, there were marked increases in the rate of urinary excretion of calcium and magnesium, and a sharp fall in urinary pH. There were also post‐prandial increases in the plasma levels of calcium and magnesium, and a fall in blood pH and plasma bicarbonate concentration. By analogy with the effects of metabolic acidosis in other species, it seemed likely that the hypercalciuria in the sheep was causally related to the change in acid‐base balance after feeding.

It was concluded that the excretory changes reflected the response of the kidney to intercompartmental shifts of body fluid following the potent stimulus to salivary secretion during eating.

In these experiments, the excretion of inorganic phosphate was extremely low, and the absence of this urinary buffer was probably an important factor contributing to the abrupt and considerable fall in urinary pH after feeding.
THE EFFECTS OF VARIATIONS IN WATER OR POTASSIUM INTAKE ON THE RENAL EXCRETION OF POTASSIUM IN SHEEP
Authors: Scott D.
Published: December 2014

By infusing water into the rumen of sheep receiving a fixed potassium intake the relationship between excretion of potassium and urine volume was examined.

Both the osmotic pressure and the concentration of potassium in the urine fell as the urine volume was increased, but the amount of potassium excreted was not affected by urine volume provided this was above 1·0 to 1·5 1./day.

When the potassium intake of sheep was increased through the range 236–1186 m.equiv./day there was a proportional increase in the amount of potassium excreted in the urine.

Between 236 to 889 m.equiv./day there was no change in the amount of potassium filtered across the glomerulus, but above this the amount of potassium filtered across the glomerulus increased. This result suggests that when potassium intake is very high a proportion of the potassium filtered across the glomerulus may augment the secretory process in eliminating dietary potassium excesses.
CHANGES IN THE ULTRASTRUCTURE OF RAT MYOCARDIUM INDUCED BY HYPOKALAEMIA
Authors: Emberson J. W. , Muir A. R.
Published: December 2014

Changes in the ultrastructure of adult rat ventricular muscle induced by in vitro perfusion with hypokalaemic Krebs‐Ringer solutions are described. In all experiments the [Ca2+] was 1·27 mM./l. After perfusion with [K+]=0, the myofibrils show severe contractures; after [K+]=1·19 or 2·5 mM./l. perfusion, disintegration of the thin filaments was shown; disappearance of myofibrillar insertion plaques at the intercalated discs was observed after perfusion with [K+] ≤ 1·19; with 〉 2·5 mM./l [K+], normal ultrastructure was retained.
EXTRAVASCULAR PROTEIN IN THE RENAL MEDULLA
Authors: Moffat D. B.
Published: December 2014

The permeability to protein of the vessels of the renal medulla in the rat was studied by intravenous injection of Evans' Blue or fluorescent‐labelled serum, followed by perfusion of the whole vascular system with saline. The vessels of the inner medulla and the vasa recta of the vascular bundles of the outer medulla were found to be rapidly and freely permeable to protein. Electron microscopy, after the injection of ferritin, Thorotrast or colloidal gold, showed the vessels probably concerned in the protein leak to be ascending vasa recta and the capillaries of the medulla. The findings support suggestions that extravascular albumen is important in the process of concentration of the urine.
PLASMA OSMOLALITY AND SALT GLAND SECRETION IN THE DUCK
Authors: Ash R. W.
Published: December 2014

Secretion by the supra‐orbital glands of conscious Aylesbury ducks began when plasma osmolality and [Na+] were increased by 2–8 per cent after oral administration of hyperosmotic NaCl solution. Peak rates of secretion occurred when these parameters were elevated by 8–19 per cent. Oral administration of water in volumes sufficient to decrease plasma osmolality and [Na+] below these values abolished or reduced the flow of secretion.

Comparable or larger increases in plasma osmolality produced by hyperosmotic KCl solution administered orally or by intravenous injection of urea or dextrose failed to evoke secretion.

Intravenous injection of hyperosmotic sucrose or mannitol increased plasma osmolality and decreased plasma [Na+] but evoked secretory responses which declined although plasma osmolality remained increased.

An osmotic component appears to be involved in the secretory mechanism of the salt glands but the relation between secretion and plasma osmolality is not simple and probably depends on the permeability of certain cells to different solutes.
THE INFLUENCE OF LUNG SHRINKAGE ON BREATH HOLDING TIME
Authors: Godfrey S. , Edwards R. H. T. , Warrell D. A.
Published: December 2014

The influence of lung shrinkage on the breath holding time was studied in three normal males. The rate of shrinkage was increased two to three fold either by slow expiration or by reducing gas density in a hypobaric chamber. For any given lung volume the relationship between breath holding time and pCO2 was defined by a rebreathing method which allowed breath holds to be performed at progressively increasing levels of pCO2. Hypoxia was avoided throughout and the ventilatory response to CO2 remained constant irrespective of ambient pressure.

The breath holding time for any given pCO2 was usually longer the larger the lung volume. Increasing the rate of lung shrinkage by either method did not alter the relationship between breath holding time and pCO2. There was no constant relationship between the pCO2 and the lung volume at the breaking point of a breath hold. These findings are discussed in the light of previous work and it is concluded that the sensation arising during breath holding cannot be fully explained in terms of any combination of pCO2, lung volume and lung shrinkage.
PULMONARY VASOMOTOR RESPONSES IN THE CAT; THE EFFECTS AND INTERRELATIONSHIPS OF DRUGS, HYPOXIA AND HYPERCAPNIA
Authors: Barer Gwenda R. , McCurrie Janice R.
Published: December 2014

In anæsthetized artificially‐ventilated cats, one lobe of a lung was perfused at a constant rate of flow with arterial blood. Under these conditions changes in pulmonary arterial pressure at end‐expiration, in the absence of significant changes in left atrial pressure, were assumed to indicate changes in pulmonary vascular resistance. Hypoxia and hypercapnia, produced by changing the ventilating gas mixture, caused increases in pulmonary vascular resistance. Infusion into the pulmonary artery of noradrenaline, dopamine, histamine and 5‐hydroxytryptamine caused increases in pulmonary vascular resistance, and infusions of isopropylnoradrenaline caused decreases. The β blocking agent propranolol caused increases in pulmonary vascular resistance, and the α blocking agent phentolamine caused decreases. Propranolol reduced the pulmonary vasodilator action of isopropylnoradrenaline. Phentolamine temporarily reduced or abolished the actions of noradrenaline, dopamine and histamine on the pulmonary circulation; the action of 5‐hydroxytryptamine was less affected. Phentolamine reduced or abolished the action of hypoxia for a period corresponding to that in which the actions of catecholamines and histamine were reduced. The histamine‐liberating substance BW 48/80, in addition to causing effects attributable to histamine‐release, had effects similar to phentolamine; it temporarily reduced the actions of hypoxia, noradrenaline, dopamine and histamine on the pulmonary circulation; the action of 5‐hydroxytryptamine was less affected. The action of hypoxia was not reduced by bretylium; after mepyramine it was not abolished but was sometimes slightly reduced.
EFFECTS OF SEX, STRAIN AND ENVIRONMENTAL TEMPERATURE ON THE COMPOSITION OF THE BODY LIPIDS OF MICE
Authors: Harland W. A. , Barnett S. A.
Published: December 2014

The composition of the white adipose tissue of adult A2G/Tb and C57BL/Tb mice was studied in two environmental temperatures, 21° C and ‐3° C. Females had more palmitic, oleic and stearic acids than males, less palmitoleic and linoleic. C57BL/Tb mice tended to differ from A2G/Tb in the same way as females differed from males. Mice reared in the cold environment did not differ consistently in fat composition from controls; but adult mice transferred to the cold for four weeks had more myristic, palmitic and palmitoleic acids, less oleic.
SKIN TEMPERATURE OF THE RABBIT EAR DURING DEGENERATION OF ITS SYMPATHETIC NERVE SUPPLY
Authors: Emmelin N. , Ohlin P.
Published: December 2014

The skin temperature of the ears was recorded in conscious rabbits. A marked decrease in temperature, lasting for some hours, appeared 20–26 hours after extirpation of the superior cervical ganglion. This phenomenon is compared with the degeneration secretion of saliva and the degeneration contraction of the nictitating membrane, and attributed to leakage of transmitter from the degenerating vasoconstrictor fibres in amounts sufficient to contract the blood vessels.
THE EXTERNAL WATER EXCHANGES OF NORMAL LABORATORY DOGS
Authors: O'Connor W. J. , Potts D. J.
Published: December 2014

Bitches on a fixed food intake were kept in metabolism cages. Urinary volume, drinking and body weight were measured each day and loss of water by evaporation calculated.

The mean evaporative loss of individual dogs varied from 8 to 116 g/kg/day; this could be accounted for by differences in the behaviour of the dogs resulting in different amounts of activity in the cages. Evaporative loss also varied widely from day to day. In direct observations in the laboratory evaporative loss of dogs at rest was about 1 g/kg/hr and this was increased by mild exercise to about 5 g/kg/hr. The environmental conditions were never warm enough to significantly affect evaporative loss.

The amount of water drunk by each dog varied from 4 to 109 ml./kg/day; the active dogs with high evaporative loss drank most water, the water intake thus approximately matching evaporative loss. Details of the drinking were recorded by a meter. Much of the drinking occurred during the times of the day when the animals were most active, and consisted of small drinks of 30–100 ml. Water given by stomach tube inhibited drinking for as long as 23 hr. A period of water deprivation increased drinking, usually in the form of large drinks of over 100 ml.

The mean urine volume varied in different periods of observation from 80–380 ml./day; the urine was of high concentration, about 1600 m‐osmole/l. The volume was not related to activity of the dogs and varied little from day to day. The main determinant of the volume of the urine appeared to be the rate of excretion of solutes which varied very little because of the fixed daily intake of food. There were only a few days on which the urine was of high volume and dilute; in discussion it is stated that this means that varying release of antidiuretic hormone played little part in determining the urine volume and in the regulation of water balance.

A small dose of water (about 5 ml./kg body weight) given by stomach tube always prevented drinking; a larger dose was required to produce water diuresis. This explains why water diuresis rarely occurred in dogs drinking naturally.

Water balance was achieved because the evaporative loss due to variable activity was matched by drinking.
ROLE OF LYMPHATIC SYSTEM IN WATER AND SOLUTE TRANSPORT FROM RAT INTESTINE IN VITRO
Authors: Lee J. S.
Published: December 2014

The results of the present study confirm previous observations and provide further evidence that water and solute are primarily transported from the intestine by the lymphatic system of rat jejunum in vitro, regardless of the nature of the serosal bathing medium (moist air, mineral oil or Ringer solution), or degree of intestinal motility. The transport of fluid by the venous system was negligible under all circumstances so far observed. Venous transport occurred only over a brief duration but lymphatic transport continued with little diminution in rate for at least 40 min. Lymph flow decreased with the increase of mucosal fluid osmolarity but was not affected by changing serosal fluid osmolarity. Lymph was always isosmotic with the mucosal fluid whether the latter was hypo‐, iso‐, or hypertonic. The composition of lymph with respect to concentrations of glucose; Na, K and Cl was the same as that of the absorbed fluid. The glucose concentration in the lymph was closely related to that in the bathing fluid on the mucosal side, rather than to that on the serosal side. It is concluded that the formation of lymph in the intestine is closely associated with water and solute absorption.
THE DISTRIBUTION OF THE PRINCIPAL INORGANIC IONS IN SEMEN FROM THE VAS DEFERENS OF THE DOMESTIC FOWL AND THE CONTENT OF CARBON DIOXIDE IN THE SEMINAL PLASMA
Authors: El Jack M. H. , Lake P. E.
Published: December 2014

The distribution of sodium, potassium, calcium and magnesium between the spermatozoa and plasma in the semen of the vas deferens of the domestic fowl has been determined by atomic absorption spectrophotometry. Chloride in the seminal components was analysed by an electrometric titration method and carbon dioxide in the seminal plasma was analysed using gas chromatography.

The contents of potassium and magnesium were much higher, and those of sodium, calcium and chloride lower in the spermatozoa than in the seminal plasma. The amount of sodium in the plasma of the vas deferens was about the same as that in blood plasma, but the amounts of potassium and magnesium were greater in the seminal plasma. The amount of chloride was small in the seminal plasma and its significance in relation to the ionic balance in the fluid is discussed.
RENAL EXCRETION OF POTASSIUM AND ACID BY SHEEP
Authors: Scott D.
Published: December 2014

Infusion of HCl into the rumen of sheep led to a fall in the pH of the urine and to the reabsorption of bicarbonate from the urine. Excretion of acid in the urine rose until it was about equal to the amount of acid given into the rumen. There was very little titratable acid present in the urine and over 90 per cent of the acid excreted was in the form of ammonium ions. The limitation in the excretion of titratable acid seems to be related to the observation that sheep normally excrete very little phosphorus (as phosphate) in the urine.

The renal response to acidosis in sheep was not influenced by the amount of potassium in the diet.
NERVOUS TRANSMISSION IN THE SUPERIOR CERVICAL GANGLION OF THE THIAMINE‐DEFICIENT RAT
Authors: Perri V. , Sacchi O. , Casella C.
Published: December 2014

The amplitude of the post‐ganglionic potential was measured in isolated preparations of the superior cervical ganglion from rats at different stages of thiamine deficiency.

At low frequency stimulation (0·5/sec) a decrease in the post‐ganglionic potential amplitude was not observed until the final stages of thiamine deficiency. At high frequency stimulation (20/sec) the post‐ganglionic potential of the thiamine‐deficient rats showed an early and much more pronounced decrease in comparison with that observed in both normal animals and pair‐fed controls.

The amplitude and conduction velocity of the different components of the sympathetic cord action potential were unaffected by thiamine deficiency.
CALCIUM HOMEOSTASIS IN THE FOETAL GUINEA PIG
Authors: Graham R. W. , Scothorne R. J.
Published: December 2014

Plasma total calcium levels have been studied in pregnant guinea pigs and their foetuses from 26 days of gestation to term. Between 28 days and 33–39 days the foetal plasma calcium falls from nearly the maternal level (9·6 mg/100 ml.) to 5·5 mg/ 100 ml. Thereafter the foetal plasma calcium rises, reaching the maternal level at term. No trend is found in the maternal levels. Foetal skeletal ossification was studied using an alizarin stain technique. Ossification centres appeared first in the clavicle, face and skull at 26 days of gestation. After 27 days gestation (foetal plasma protein = 1 g/100 ml.) there is a steady rise in foetal plasma protein level and at term foetal and maternal levels are approximately equal. Between 41 days gestation and term foetal blood is consistently more acid than maternal blood and has a higher pCO2 and lower pO2. There is no evidence of a progressive change during gestation in pH, pO2 or pCO2 in either foetal or maternal blood. It is concluded that the fall in foetal plasma calcium between 28 days and 33–39 days gestation may be due to calcification of the foetal skeleton before the full establishment of calcium homeostasis in the foetus. Increasing foetal plasma protein concentration or foetal parathyroid activity may account for the rise in foetal plasma calcium after 33–39 days.
ON THE IN VITRO ‘ACTIVE TRANSPORT’ OF ALDOPENTOSES BY THE RAT JEJUNUM
Authors: Bell D. J.
Published: December 2014

The possibility of an ‘active intestinal transport’ of D‐xylose, D‐ribose and L‐arabinose at low concentrations (9 to 40 µg/ml.) was studied aerobically using the everted jejunal sac. Only D‐xylose could be shown to be concentrated within the sac. D‐glucose (100 µg/ ml.) completely inhibited this concentration of xylose.
THE EFFECTS OF LEFT ATRIAL DISTENSION UPON URINE FLOW FROM THE ISOLATED PERFUSED KIDNEY
Authors: Carswell F. , Hainsworth R. , Ledsome J. R.
Published: December 2014

An isolated kidney obtained from a donor dog was perfused at constant pressure with blood from the femoral artery of a recipient dog. The left atrial pressure of the recipient dog was increased by approximately 20 cm H20 by inflating a balloon in the left atrium. Left atrial distension caused an increase in urine flow and sodium excretion from the isolated perfused kidney and on a few occasions from the dog's own kidneys. The results support the view that a blood borne agent is responsible for the diuretic response to left atrial distension.
QUANTITATION OF FUNCTIONAL DIFFERENCES BETWEEN THE TWO SEGMENTS OF THE RAT PROXIMAL TUBULE IN THE HANDLING OF CHLORPHENOL RED AND HIPPURAN‐131I
Authors: Sottiurai Vikrom , Longley James B.
Published: December 2014

The work reported in this paper attempts to associate several functions known to occur in the renal proximal tubule with either the convoluted or straight segment of this tubule, and from observations made on a zonal basis to offer conclusions concerning the specific functions of these segments. Measurements were made of chlorphenol red and hippuran‐131I in kidneys of diuretic rats which had one ureter ligated to create stop‐flow conditions. Autoradiographs were also obtained from the hippuran‐131I study.

The results show that chlorphenol red and hippuran‐131I accumulate in the cortex in kidneys after ligation of the ureter and in the outer stripe of the outer zone of medulla in free urine flow kidneys.

The measurements made in renal tissue when compared with the plasma and urine levels of chlorphenol red and hippuran‐131I obtained during the experiments, indicate that these substances are actively secreted at both the vascular and luminal margins of the epithelial cell of the convoluted segment and passively reabsorbed by the epithelial cells of the straight segment.