bluuebunny/crossref_metadata_2025_split huggingface dataset:
BALANCES OF WATER AND SODIUM IN THE RUMEN DURING FEEDING: OSMOTIC STIMULATION OF SODIUM ABSORPTION IN THE SHEEP
Authors: Stacy B. D. , Warner A. C. I. 
Published: December 2014

When sheep ate a dry ration containing added sodium chloride the concentration of sodium in the rumen liquor did not increase. When solutions containing amounts of sodium similar to those eaten with the feed were administered via rumen fistulæ to fasting sheep, they caused a rise in sodium concentration that was sustained for at least 4 hr. Different results were obtained when the same dose of sodium chloride was given to sheep in which the rumen contents were made hypertonic by the addition of other solutes (potassium chloride or mannitol‐urea). Instead of rising, the sodium concentration fell 4 hr. after treatment.Changes in the water content of the rumen were traced with a soluble marker, the 51Cr complex of ethylenediaminetetra‐acetic acid. After feeding, but not after solute administration, there was clear‐cut evidence of increased entry of body water into the rumen, the dilution rate increasing from 0·07–0·11 hr.‐1 to 0·19–0·28 hr.‐1. Total salivary secretion was measured in an animal with an œsophageal fistula and the results indicated that the increased water entry into the rumen was due to stimulation of saliva production on feeding.By making several assumptions, sodium and water balances in the rumen were derived from the experimental data. In the fasting state the calculated sodium absorption was 6–16 m. equiv/ hr.; over the 2 hr. period after feeding or solute administration the value was 36–62 m.equiv/hr.It was concluded that hypertonic conditions, as foumd after feeding or solute loading, stimulate the absorption of sodium from the rumen. The physiological implications of the findings are discussed in terms of the sheep's response to the diversion of sodium and water into the rumen on feeding.
QUANTITATIVE ASPECTS OF THE RECIRCULATION OF LYMPHOCYTES; AN ANALYSIS OF DATA FROM EXPERIMENTS ON SHEEP
Authors: Hall J. G. 
Published: December 2014

By cannulating the efferent ducts of each of twenty popliteal lymph nodes in merino ewes it was possible to collect the lymph and thus measure the outputs of lymphocytes from these nodes for periods of over 100 hr., under physiological conditions.A linear correlation between the weight of a lymph node and its output of lymphocytes was demonstrated. Although the statistical significance of this correlation was low, predictions based upon it agreed with the observed results of other investigations. It was therefore concluded that on average, in adult sheep, a lymph node weighing 1 g. discharges 30 million lymphocytes/hr. into the efferent lymph. It was shown that lymphocytes from the afferent lymph and de novo production within the node make only a small contribution to this number. Most of the lymphocytes in the efferent lymph must be supplied therefore directly from the blood which flows through the node.Measurements of the venous outflow from individual prefemoral nodes in anæsthetized Clun Forest sheep showed that the blood flow through lymph nodes is of the order of 1 ml./min./g. node wt. Using this value it was calculated that some 12 per cent of the lymphocytes in the blood flowing through a node must leave the blood, pass through the substance of the node and enter the efferent lymph.
OBSERVATIONS ON THE MICROCIRCULATION IN THE RABBIT EAR CHAMBER
Authors: Stehbens W. E. 
Published: December 2014

Observations on flow patterns and platelet behaviour at vascular forks have been made in small blood vessels of rabbit ear chambers. At vascular forks and junctions, localized variation in the width of the marginal plasma zone has been noted corresponding to areas at which intimal thickening is known to occur in distributing arteries.Platelet sticking and the formation of microthrombi did not tend to favour vascular forks or junctions. Observations did not indicate that eddy currents predisposed platelets to stick or to form thrombi.
THYROGLOBULIN IN THE LYMPH DRAINING FROM THE THYROID GLAND AND IN THE PERIPHERAL BLOOD OF RATS
Authors: Daniel P. M. , Pratt O. E. , Roitt I. M. , Torrigiani G. 
Published: December 2014

It has previously been thought that organic iodine leaves the thyroid gland only in the form of iodoamino acids which are derived from the breakdown by the thyroid cells of the thyroglobulin stored in the colloid. It has now been shown that a considerable amount of iodoprotein also leaves the thyroid gland in the thyroid lymph and that most, if not all, of this iodoprotein is actually thyroglobulin. The iodoprotein in the thyroid lymph was studied by two different techniques, either by chemical separation of iodoprotein after giving the rats relatively small doses of 125I‐inorganic iodide or by measuring the amount of thyroglobulin by an immunoassay, which avoided the necessity of giving the animals radioactive iodine in vivo.The iodoprotein content of the thyroid lymph is raised sharply by giving the rats thyroid stimulating hormone and also by thyroid massage which expresses the lymph contained within the lymphatics of the thyroid gland. Iodoprotein is virtually absent from peripheral lymph (i.e. lymph not containing any thyroid lymph). The peripheral blood of rats also contains small but appreciable amounts of thyroglobulin.The implications of the presence of thyroglobulin outside the thyroid gland are discussed.
EFFECT OF ENVIRONMENTAL TEMPERATURE ON THE CLOSURE OF FULL THICKNESS SKIN WOUNDS IN THE RAT
Authors: Cuthbertson D. P. , Tilstone W. J. 
Published: December 2014

Full thickness skin wounds in hooded Lister rats of the Rowett Institute strain kept at an environmental temperature of 30° C closed more rapidly than did those in similarly wounded rats housed at 20° C. The differences were statistically significant. This response was exhibited by both sexes and was found in experiments carried out at both Aberdeen and Glasgow.The wounds in male rats were found to close more rapidly than those in female rats housed at the same temperature. The rectal temperature of the animals was not affected by the environmental temperature but the temperature of wounded skin was significantly higher (ca. 0.9° C) in the animals held at 30° C. Also in these latter rats, the response of skin temperature at the wound margin differed markedly from those at 20° C.Rats at 20° C pair fed to rats at 30° C, who even prior to wounding eat less than those at 20° C, did not respond differently from rats allowed food ad libitum at the lower temperature.The epithelium of the wounds advanced at a linear rate in the final stages of closure.
POTENTIATION BY AMINOGUANIDINE OF THE SENSITIVITY OF SHEEP TO HISTAMINE GIVEN BY MOUTH. EFFECT OF AMINOGUANIDINE ON THE URINARY EXCRETION OF ENDOGENOUS HISTAMINE
Authors: Sjaastad Ö. V. 
Published: December 2014

The sensitivity of sheep to orally administered histamine was greatly increased by aminoguanidine, a substance which inhibits histaminase (diamine oxidase, E.C. 1.4.3.6.). The increment in urinary free histamine after giving histamine by mouth (1·0–10·0 g. histamine diphosphate) was about 22 times larger in aminoguanidine‐treated sheep than in untreated ones. Furthermore, toxic manifestations were observed when 1 g. of histamine diphosphate or more was given to aminoguanidine‐treated sheep, whereas doses as high as 10 g. only had a slight effect on untreated animals.When aminoguanidine was given, and oxidative deamination thus largely prevented, methylation of histamine seemed to increase.Aminoguanidine increased the urinary excretion of endogenous free histamine on average by a factor of about 12. The above mentioned results indicate that oxidative deamination of histamine is more important in sheep than in species previously examined.
PRESSURE MEASUREMENTS IN THE LESSER CIRCULATION OF THE NEWBORN RABBIT
Authors: Dennis Jennifer 
Published: December 2014

An attempt is described to investigate whether some of the physiological responses of the pulmonary vascular bed in anæsthetized rabbits aged 0–31 days differ from those observed in other species, and it is shown that accurate measurements of phasic right ventricular pressure can be made in small animals with high heart rates using standard equipment.A constant relationship of resting peak right ventricular to mean pulmonary arterial pressure is demonstrated in the resting state, but there are indications that the quantitative relationship changes with the circumstances. The variation with age of systemic and peak right ventricular pressure is shown; the latter changes are different from those described in other species and together with results obtained during hypoxia and asphyxia provide indirect evidence of ductus arteriosus closure on day 3. Pulmonary vascular pressor responses comparable to those of other species are never seen in the first 3 weeks and the fall in systemic pressure in response to asphyxia in very young animals is not due to coincident intense pulmonary vasoconstriction but could be explained by hypoxic dilatation of a patent ductus. A systemic response to hypoxia opposite to that to asphyxia is observed in rabbits older than 4 days. There is no evidence that intravenous infusion of acetylcholine in well‐oxygenated or hypoxic newborn rabbits has any direct effect on the pulmonary vascular bed.
A COMPARISON BETWEEN THE INHIBITORY EFFECT OF PERCHLORATE ON IODIDE AND PERTECHNETATE CONCENTRATIONS IN SALIVA IN MAN
Authors: Harden R. McG. , Alexander W. D. , Shimmins J. , Robertson J. W. K. 
Published: December 2014

The inhibitory effect of the perchlorate ion on the concentration of iodide and pertechnetate has been studied in human parotid saliva, collected under resting conditions and during stimulation. The saliva/plasma (S/P) 132I and 99mTcO4‐ ratios and the salivary I and TcO4‐ clearances fell after perchlorate administration. The percentage fall in the S/P ratios was greatest under resting conditions.The effect of increasing doses of perchlorate on the S/P I and TcO4‐ ratios was studied. There was a linear inverse relation between the S/P ratios and log. dose of perchlorate at perchlorate doses of 3 mM/day and greater. I‐ and TcO4‐ are not inhibited to the same extent by perchlorate. The ratio of the salivary I‐ to TcO4‐ clearance, measured simultaneously, was higher after perchlorate administration. The dose of perchlorate corresponding to inhibition of the S/P TcO4‐ ratio to half the control value was less than the dose required for a corresponding decrease in the S/P I‐ ratio.The dose of perchlorate required to depress the S/P I‐ and TcO4‐ ratios to 50 per cent of the control value and to an absolute value of 0·5 was compared to the dose of iodide required to produce similar falls. It was concluded that perchlorate is a more potent inhibitor of the salivary iodide concentrating mechanism than iodide given in molal equivalent doses. Iodide, however, in contrast to perchlorate, depressed the S/P I‐ and TcO4‐ ratios to the same extent. Although TcO4‐ shares with I‐ one common transport mechanism, there are also differences in the transport of the ions from the blood into the saliva.
AFFERENT PATHWAYS AND EFFERENT MECHANISMS IN THE BLADDER VISCERO‐VASCULAR REFLEX
Authors: Taylor D. E. M. 
Published: December 2014

The afferent and efferent limbs of the bladder viscero‐vascular reflex have been studied in cats under chloralose anæsthesia. The maximum change in arterial blood pressure in response to applied tension was obtained from the region of the trigone and bladder neck; lesser responses were obtained from all other regions of the bladder. The response to rapid bladder filling was little affectecd by hypogastric nerve section. Although it was much reduced after section of sacral posterior roots, it was not abolished until higher posterior roots had also been cut, sometimes Up to T 10.In the presence of an intact nervous system, during the early stages of slow bladder filling hind limb vasoconstriction occurred, but there was compensatory limb vasodilation and bradycardia so that no change in blood pressure occurred. Later in the course of filling changes in blood pressure occurred and were associated with vasoconstriction in fore as well as hind limbs and subsequently tachycardia. Occasionally with extreme distension cardiac arrhythmias, such as ventricular or nodlal extra systoles, appeared. There was less compensation when filling was faster, and no compensation after baroreceptor denervation. Cardiac denervation abolished the changes in heart rate, but the circulatory changes in the limbs were unaffected.It is concluded that bladder viscero‐vascular reflexes are initiated mainly by tension changes in the region of the trigone and bladder neck; the afferent path can be either the hypogastric or pelvic splanchnic nerves, although the predominant route is the latter; and in the presence of intact baroreceptor reflexes, changes in the circulation occur early and before any alteration in the arterial blood pressure.
SOME EFFECTS OF l‐HYOSCINE HYDROBROMIDE ON POST‐ROTATORY SENSATION AND NYSTAGMUS IN MAN
Authors: Benson A. J. , Brand J. J. 
Published: December 2014

In a balanced double‐blind trial six subjects were given, on three successive days, an injection of 0·3 mg. or 0·6 mg. of l‐hyoscine hydrobromide or normal saline, 30 min. before rotational tests of vestibular function were performed. Hyoscine caused a significant (P = 0·01) depression of the ‘slope’ of the sensation cupulogram without alteration of the extrapolated ‘threshold’. This effect was not significantly greater with the higher dose of the drug. In subjects who had received hyoscine there was an appreciable suppression of the post‐rotational nystagmic response, and slow pendular oscillations of the eyes were frequently recorded. These effects were antagonized by mental arithmetic.It was concluded that hyoscine increased adaptation in the vestibular sensory system and released the oculomotor system from the ascending influence of vestibular and reticular projections.
THE EFFECT ON BLOOD AND URINE OF THE INGESTION OF SODIUM BICARBONATE
Authors: Matthews D. L. , O'Connor W. J. 
Published: December 2014

O·145M NaHCO3 given by stomach tube to conscious dogs caused a fall in plasma solids (protein), decrease in plasma Cl and increase in HCO3; pH of the arterial blood increased but any increase of arterial PCO2, was not significant; plasma K fell. The urine after 0·145M NaHCO3 contained increased amounts of Na with only a small increase in Cl. The increased excretion of Na+ was mainly accompanied by a large excretion of HCO3‐, and the urine became alkaline and contained little NH4+. Changes in the excretion of inorganic PO4, SO4 and K were small.Comparison was made with the effects of the same doses of Na given as 0·122M NaCl+0·023M NaHCO3. This caused an equal fall in plasma solids but no change in plasma Cl, HCO3 and K. The urinary excretion of Na+ increased to rates approximately the same as those produced by NaHCO3 but the main urinary anion was Cl‐, the excretion of which was greatly increased. There was a small excretion of HCO3‐ with larger doses.It is concluded that an important agent determining increased excretion of Na is dilution of the plasma protein, which is common to both types of experiment. The changes in plasma Cl and HCO3 appear to be the factor which determines whether the increased excretion of Na+ is accompanied mainly by HCO3‐ or Cl‐.
THE EFFECTS OF INTRAVENOUS INFUSION OF KCl OR HCl ON THE RENAL EXCRETION OF POTASSIUM IN SHEEP
Authors: Scott D. 
Published: December 2014

Intravenous infusion of potassium chloride in sheep led to a rise in the concentration of potassium in the plasma, and to an increase in the rate of excretion of potassium in the urine, which rose rapidly until the rate of excretion of potassium was about equal to the rate of infusion of potassium. During potassium infusion the rate of excretion of potassium in the urine in some experiments exceeded the rate of filtration of potassium across the glomerulus, indicating net secretion of potassium by the renal tubules. Intravenous infusion of HCl did not modify the renal response to intravenous infusion of potassium, but only a small proportion of the acid infused appeared in the urine.Chronic acidosis resulting from intra‐ruminal infusion of HCl led to an increase in the rate of net acid excreted but no change in the rate of excretion of potassium in the urine. A large proportion of the net acid excreted was in the form of the ammonium ion and little was present as titratable acid. This result suggests that the excretion of large amounts of potassium in the urine of the sheep may limit the rate of excretion of titratable acid.
GLUTAMINE METABOLISM IN THE PERFUSED RAT HEART
Authors: Ottaway J. H. 
Published: December 2014

Changes in the concentration of glutamate, glutamine, alanine and aspartate have been measured during perfusion of isolated rat hearts. During a 60 min perfusion the concentration of glutamine fell by two‐thirds: the extent of the fall is consistent with hydrolysis by cardiac glutaminase. The concentrations of the other 3 amino acids did not change significantly in the heart, but alanine and aspartate, and to a less extent glutamate, accumulated in the perfusate in amounts equivalent to the glutamine which had disappeared.When 10 µg./ml. bovine growth hormone was added to the perfusate, the tissue glutamine level was slightly higher and about 1 µmole glutamine/g. heart/hour accumulated in the perfusate. The concentrations of the other amino acids, both in the heart and in the perfusate, remained essentially unchanged.The significance of these results with respect to cardiac glutamine metabolism is discussed.
DISTRIBUTION AND FATE OF Mn54 IN THE RAT, WITH SPECIAL REFERENCE TO THE C.N.S
Authors: Dastur Darab K. , Manghani Daya K. , Raghavendran K. V. , Jeejeebhoy K. N. 
Published: December 2014

In view of the still prevalent problem, in certain mining communities, of chronic manganese toxicity affecting the C.N.S., and the paucity of experimental data explaining the mechanism of this, the distribution and fate of isotopic Mn54 in different organs and tissues and in the whole body of the rat was studied over a period from 15 min to 34 days after intraperitoneal injection of an Mn54 maleate solution.While the curve for the whole body and for most organs could be resolved into two exponential components, the slower component was not present for the C.N.S. The blood seemed to serve as a transport medium receiving and discharging the Mn54 rapidly. While most organs showed a gradual decline with time in the counts per minute per gram of tissue and in the retained dose, the brain and the spinal cord exhibited a steady rise from the beginning to end. The suprarenal, pituitary, heart and bone also evidenced this to some extent. A greater capacity for relative retention of a small dose of manganese by the C.N.S. might be responsible for its selective vulnerability in chronic manganism.
POST‐OCCLUSION ‘HYPEREMIA’: A STUDY ON A MODEL
Authors: Rodbard Simon , Takeda Yoshiyuki , Takacs Lajos 
Published: December 2014

The hydrodynamic properties of the capillaron, i.e. a compliant capsule which encloses one or more soft‐walled permeable capillaries together with extravascular fluid, can account for the known characteristics of reactive hyperemia. This has been demonstrated in a model of the capillaron. A constant arterial pressure head delivered fluid to the enclosed capillary and thence to a venous sink. The flow rate varied with the perfusion pressure and with the calibre of the soft‐walled vessel. Vascular calibre depended on the transmural capillary pressure. A positive pressure opens the capillary completely and the flow rate for the perfusion pressure is maximal. Capillary permeability results in ‘ultrafiltration’ which raises the extravascular pressure, thereby lowering the transmural pressure, until the capillary is partially collapsed. In the ‘resting’ or basal state, the flow rate through the capillaron is only a small percentage of the maximal flow through the system. Occlusion of the arterial supply is followed by drainage of extravascular fluid across the permeable membrane and tissue pressure falls progressively with the duration of the occlusion. Reopening of the artery raises the intravascular pressure and the positive transmural pressure opens the capillary, with the result that flow approaches maximal values. The flow during the hyperemic phase is affected by the duration of occlusion, the arteriovenous perfusion pressure, the permeability of the capillary, and the compliance of the capsule.The effects of these changes on transcapillary fluid exchanges are described. Several variations of the hyperemic manoeuvre, including the effects of arterial occlusion without hyperemia, hyperemia without occlusion, hypoemia, the inter‐ relationships between blood and ultrafiltrate flows, and the potential exchanges of diffusible and of filterable materials are demonstrated and shown to correspond to the findings in man and animals.
THE INTRAVENOUS GLUCOSE TOLERANCE TEST IN THE PIG
Authors: Anderson D. M. , Elsley F. W. H. 
Published: December 2014

After intravenous injection of 50 g glucose the blood glucose concentration in sows declined very quickly from the high concentrations initially found. The blood glucose concentration always returned to the fasting concentration within the period 18–45 min after glucose injection. The rate at which the glucose was removed was a function of the total blood glucose concentration.After the blood glucose concentration returned to the fasting concentration, the concentration continued to fall, concentrations of 5–10 mg/100 ml. being achieved regularly with no overt signs of hypoglycaemia.The time required for the blood glucose concentration to return to the fasting glucose concentration was found to be the most repeatable quantitative assessment of the test in the pig.
BLOOD VOLUME CHANGES DURING PREGNANCY AND LACTATION OF SOWS
Authors: Anderson D. M. , Elsley F. W. H. , McDonald I. 
Published: December 2014

Plasma volume and haematocrit were measured at approximately 20 days intervals in 3 gilts (sows in their first pregnancy and lactation) throughout pregnancy and in 2 of these gilts during lactation. Measurements were made at the beginning and end of pregnancy in a further 9 sows and also at mid‐pregnancy in 4 of these latter sows.In the gilts PV declined during the first 40 days and then increased until parturition. In lactation the PV continued to rise during the first 14 days and then decreased steadily until weaning. Calculated RCV increased linearly during pregnancy and fell immediately after parturition.The results obtained from the sows again showed only a sight rise in PV and RCV until day 70 and then a sharp rise until parturition. There was no relationship between the increase in PV and the weight of the litter born.
OPTIC NERVE FIBRE COUNTS AND RETINAL GANGLION CELL COUNTS DURING DEVELOPMENT OF XENOPUS LAEVIS (DAUDIN)
Authors: Wilson Margaret A. 
Published: December 2014

An account is given of the development of the optic nerve in Xenopus laevis (Daudin). The stages studied were 35, 38, 46, 52, 58, immediately post‐metamorphosis (66), the juvenile of six months from metamorphosis and the adult. Fibre counts were made from complete electron micrograph montages for all the stages investigated including the adult. Corresponding ganglion cell counts were made from sections prepared by light microscopic histology from stage 46 upwards.The large increase found in the ganglion cell population during development was also found in the optic nerve fibre counts. There was an approximate 1 : 1 relationship between the optic nerve fibres and the retinal ganglion cells.The number of fibres increased from less than 1,000 (stage 35) to 59,000 (six‐month‐old juvenile). The older adult animal possessed fewer unmyelinated fibres than the six month old juvenile, but twice as many myelinated fibres, so producing a smaller total number. It seems that the process of myelination continues well into adult life.