bluuebunny/crossref_metadata_2025 huggingface dataset:
THE ACTION OF ANTICHOLINESTERASES ON THE RESPONSE OF THE PACE‐MAKER, THE CONDUCTING SYSTEM AND THE VENTRICULAR MUSCULATURE OF PERFUSED FROG HEARTS TO ACETYLCHOLINE
Authors: Boyd I. A. , Pathak C. L.
Published: December 2014

Concentration‐response curves were obtained for the action of acetylcholine (ACh) on frog hearts perfused under controlled dynamic conditions. The cardiac output, frequency of contractions, and arterial pressure developed by the heart were continuously recorded electronically.

The minimum concentration of ACh that affected pace‐maker frequency and ventricular tone was about the same, and was unaffected by the presence of anticholinesterases. The action of ACh on pace‐maker frequency was potentiated by anticholinesterases, the degree of potentiation increasing with concentration of ACh. There was a limit to the degree of inhibition of ventricular tone attainable with ACh, this limit varying from 40 to 100 per cent in different hearts. Inhibition of ventricular tone by ACh was often unaltered, or even reduced, by anticholinesterases. The sensitivity of the conducting system to ACh varied greatly from heart to heart, and was independent of the sensitivity of either pace‐maker or ventricular muscle. The concentration of ACh required to arrest the heart was always less in the presence of anticholinesterases.

The results are explained in terms of differences in the amount and type of cholinesterase present in the component tissues of the heart, and by competition between the direct atropine‐like action of some anticholinesterases on muscle and their action in inhibiting cholinesterase.
EFFECT OF HYPOPHYSECTOMY OR TREATMENT WITH THYROXINE OR TESTOSTERONE ON SECRETORY RESPONSES AND RESPIRATORY ENZYMES OF THE SUBMAXILLARY GLAND OF THE RAT
Authors: Ohlin P.
Published: December 2014

The effect of hypophysectomy or of treatment with thyroxine or testosterone on the function of the submaxillary gland of rats was studied. (1) The dry weight of the submaxillary gland decreased by 46 per cent after hypophysectomy. The gland weight increased by 14 per cent after thyroxine and by 29 per cent after testosterone. (2) The maximal secretory response to pilocarpine was reduced after hypophysectomy. After hormonal treatment the maximal secretory response was increased when expressed per gland. It was also increased when calculated per unit weight after thyroxine, but not after testosterone. (3) The activity of succinic dehydrogenase, cytochrome oxidase and fumarase was not significantly changed after hormonal treatment when expressed per unit weight.

The results are discussed and related to known morphological changes of the submaxillary gland of rats after hypophysectomy or after treatment with thyroxine or testosterone.
PHAGOCYTOSIS OF PLATELETS BY MONOCYTES IN ORGANIZING ARTERIAL THROMBI. AN ELECTRON MICROSCOPICAL STUDY
Authors: Poole J. C. F.
Published: December 2014

The mural thrombus which initially lines fabric grafts of the aorta has been examined in the electron microscope. Evidence has been obtained that platelets undergo phagocytosis by monocytes.
THE ACTION POTENTIAL OF CARDIAC VENTRICULAR FIBRE CELLS DURING THIAMINE DEFICIENCY
Authors: Rindi G. , Rapuzzi G.
Published: December 2014

The myocardial fibre cell action potentials of rats, made thiamine deficient by a synthetic diet or by antivitamin treatment (pyrithiamine or oxythiamine), have been measured in Situ by means of fluctuating microelectrodes. Although the amplitude of the action potential was unchanged, its duration was distinctly increased, owing to a lessened repolarization. Bradycardia, which was also found in thiamine deficiency, was viewed essentially as a consequence of the slowed cellular membrane recovery processes.
INTERACTION OF ADRENERGIC ALPHA AND BETA‐RECEPTOR BLOCKING AGENTS ON THE BLOOD PRESSURE RESPONSE TO ADRENALINE AND NORADRENALINE
Authors: Sharma P. L.
Published: December 2014

The interaction of adrenergic alpha and beta‐receptor blocking agents on the blood pressure response to adrenaline and noradrenaline was studied in anaestheitzed dogs.

Dibenzyline completely blocked the pressor response to noradrenaline, and converted the pressor response to adrenaline into a depressor one. Propranolol partially restored the pressor responses to both noradrenaline and adrenaline. The increase in heart rate produced by catecholamines was completely blocked by propranolol.

In another group of dogs, propranolol was administered before dibenzyline. Propranolol potentiated the pressor responses to both adrenaline and noradrenaline. The potentiation was more marked with adrenaline than noradrenaline. The increase in heart rate produced by these catecholamines was completely blocked by propranolol. Dibenzyline reduced but did not abolish the pressor responses to both adrenaline and noradrenaline.

Propranolol partially antagonizes the action of dibenzyline. This antagonsim appears to be independent of the myocardial actions of adrenaline and noradrenaline.
THE EFFECT ON MUSCLE GLYCOGEN OF SHOCK DUE TO SPINAL CORD DESTRUCTION, AND OF HAEMORRHAGIC SHOCK WITH PERIPHERAL DENERVATION
Authors: van Gool J. , Reerink E.
Published: December 2014

In rats with shock due to spinal cord destruction (pithed rats) and severe terminal hypoglycaemia muscle glycogen remains normal, whereas it falls in shock due to other causes. To explain this difference the role of denervation on muscle glycogen was investigated.

In rats with destruction of the lower part of the spinal cord, the denervated hindlimbs showed a higher muscle glycogen concentration than the normally innervated forelimbs, in spite of severe shock. In other experiments is was found that in haemorrhagic shock one‐sided proximal interruption of the femoral nerve resulted in a higher glycogen concentration in the rectus femoris than on the other sham‐operated side. However, the same differences were found also in the gastrocnemius, whose motor nerve fibres were intact. Blockade with phenoxybenzamine prior to haemorrhagic shock abolished this difference between the denervated and intact limb completely. It is concluded that a section of the femoral nerve interrupts accompanying sympathetic adrenergic fibres to the hindlimb, thereby preventing vasoconstriction and reducing tissue hypoxia during haemorrhagic shock. The normal muscle glycogen concentration during severe spinal shock must be explained by a failure of reflexogenic hyperactivity of the sympathetic nervous vasomotor system.

In studies on the effects of peripheral denervation, the possible role of interruption of accompanying autonomic nervous fibres is often neglected.
THE LATERAL CERVICAL NUCLEUS OF THE CAT; AN ELECTROPHYSIOLOGICAL STUDY
Authors: Horrobin D. F.
Published: December 2014

Microelectrode recordings were made from the cells of the lateral cervical nucleus (LCN) in the cat. These cells can be distinguished from other units in adjacent regions of the spinal cord by antidromic stimulation from the contralateral medial lerniscus. Over 90 per cent of the cells were activated by light cutaneous stimuli. Forelimb units were more numerous than hindlimb ones. There appeared to be a crude somatotopic organization both in the nucleus and in its projection in the medial lemniscus. Several cells had branching axons. A method for the determination of the position of a branch point is described. No cells in the LCN could be fired antidromically by stimulating either side of the anterior cerebellum. Such stimulation fired only two cells trans‐synaptically, suggesting that collaterals from the dorsal spino‐cerebellar tract play a very minor role in the afferent supply to the nucleus. Stimulation of the contralateral inferior olive fired some LCN cells antidromically. The axons passing to the olive were branches of the main axons in the medial lenmiscus.
ACTION OF THE MITRAL AND AORTIC VALVES IN VIVO STUDIED BY ENDOSCOPIC CINE PHOTOGRAPHY
Authors: Hider C. F. , Taylor D. E. M. , Wade J. D.
Published: December 2014

The movements of the mitral and aortic valves within the dog's heart in its normal anatomical position have been studied by cinephotography using a cardiac endoscope. A method of artificial perfusion of the heart is described which provides optical clarity for up to five minutes of normal heart action; for times longer than this the heart still beats well, but is considered to be failing. A comparison of valve action at two different kinematic viscosities, 0·7 and 3·4 cSt., has been made. The main difference is in the stability of the mitral valve edges during diastolic filling: a fluttering motion occurs at the edges with the low viscosity perfusion, but the valve edges remain stable when a perfusate of blood viscosity is used. A possible relation between these observations and changes in flow pattern at high rates of cardiac output is discussed. The movements of both mitral and aortic valves are rapid, taking less than 9 msec. for closure of both, and between 9 and 27 msec. for opening of both. The mitral valve does not show marked bulging into the atrium during ventricular systole, neither is any preߚsystolic flick observed. The mechanism of the valve movements observed is discussed and observations on mitral valves after papillary muscle inactivation are briefly reported.
A COMPARISON OF SHAM FEEDING AND TEASING AS STIMULI FOR GASTRIC ACID SECRETION IN THE DOG
Authors: Preshaw R. M. , Webster D. R.
Published: December 2014

In three dogs equipped with an œsophagostomy and a gastric fistula, sham feeding caused a greater gastric secretory response than teasing with food. The acid output from the stomach in response to sham feeding and teasing was related to the duration of stimulation. The highest rates of acid secretion observed after sham feeding (mean 14·2 mEq/15 min.) were similar to the maximal rates during infusion of a gastrin extract (mean 15·4 mEq/15 min.) or histamine dihydrochloride (mean 14·4 mEq/15 min.).
AFFERENT NERVOUS DISCHARGE FROM THE CANINE LIVER
Authors: Andrews W. H. H. , Palmer J. F.
Published: December 2014

Afferent action potentials were recorded from dissected strands of divided hepatic nerves in the dog. Stimulation of sensory receptors could be produced by (a) injection of sodium cyanide into the hepatic circulation; (b) occlusion of the posterior vena cava, with resultant hepatic congestion; (c) mechanical increase of biliary pressure. Injection of acetylcholine into the hepatic circulation usually led to a profuse discharge in the hepatic nerves which, in some experiments, provoked an arterial pressor response, related temporally to the action potentials. Many hepatic nerves exhibited an abundant afferent resting discharge, but the nature of the receptors responsible was not determined.
EFFECTS OF VASOPRESSIN UPON THE COMPOSITION OF RAT'S KIDNEY
Authors: Abedin Zain Ul
Published: December 2014

The composition of renal medulla and cortex was studied in rats during water diuresis interrupted by lysine‐8‐vasopressin (ADH), given as a single intravenous injection or by continuous intravenous infusion, in an attempt to mimic the effect of hydropenia.

Continuous infusion of 60 µu./100 g./min. ADH for 2½ hr. (9 mu. in all) raised the osmolality of the medulla and urine to the levels found after 24 hr. of hydropenia, but these values remained lower than values reported after prolonged hydropenia. Infusion of 30 µu./100 g./min. ADH (4·5 mu. in all) was only slightly less effective. 10 mu./100 g. body weight of ADH given as a single intravenous injection increased the osmolality of medulla less than did continuous infusion of this hormone.

Accumulation of sodium in deeper medulla and at the level of thick portion of ascending limb of loop of Henle suggests that ADH may promote transport of sodium from collecting ducts and the thick ascending limb of loop of Henle or the other structures present at these levels. The amount of potassium in the deeper medulla diminished after ADH treatment. Increased amount of water at the level of the ascending limb suggests the possibility of short‐circuiting of water at this level; this would partly account for the low water content found in the deeper medulla. Accumulation of urea and ammonium in the medulla is also reported.
THE SOURCE OF ENDOGENOUS LIPID IN THE THORACIC DUCT LYMPH OF FASTING RATS
Authors: Shrivastava B. K. , Redgrave T. G. , Simmonds W. J.
Published: December 2014

The output of esterified fatty acid in the thoracic duct lymph of fasting, unanæsthetized rats decreased by 80 per cent when a bile fistula was produced. Steady infusion of sodium taurocholate, 5 or 10 mg./hr. in saline, did not reverse this fall. This suggested that it was the loss of biliary lipids and not primarily that of bile salts which was responsible for the decreased lymph lipid. The output of esterified fatty acid in bile of rats with chronic bile fistulae was small. However, experiments in which bile was returned by re‐entrant cannula and sampled only for short periods showed that operation depressed biliary lipid output for about 24 hr. and drainage of bile clearly decreased biliary lipids within 2–4 hr. In each of a group of rats with re‐entrant biliary cannulae the output of biliary lipids in the first 2 hr. of drainage was more than enough to account for the decrease in output of esterified fatty acid in fasting lymph in each rat after continuous biliary drainage was established. Gas liquid chromatography showed that before biliary drainage was established, fasting lymph lipids were rich in fatty acids characteristic of bile but after biliary drainage the fatty acid pattern closely resembled that of plasma. It is suggested that fatty acid liberated from phospholipids of bile in the intestinal lumen contribute a major portion of the esterified fatty acid of fasting lymph and that lipoproteins passing from plasma into lymph provide much of the remainder. The prompt effect of biliary drainage on phospholipid output in bile is briefly discussed.
REFLEX INCREASE IN URINE FLOW BY VERATRIDINE
Authors: Thomas Susan
Published: December 2014

In dogs anæsthetized with choralose injection of veratridine intravenously (60–70 µg.) or into the left ventricle (5–10 µg.) produced an increase in urine flow. This effect was abolished by blocking the vagi. In contrast, intra‐aortic injections of veratridine (20–40 µg.) did not increase urine flow with the vagi intact. It was therefore concluded that veratridine produces a reflex increase in urine flow by stimulating sensory receptors in the heart (presumably atrial type B receptors).
THE EFFECTS OF VOLUNTARILY CONTROLLED ALVEOLAR HYPERVENTILATION ON CARBON DIOXIDE EXCRETION
Authors: Stoddart J. C.
Published: December 2014

Four subjects hyperventilated at three carefully controlled alveolar ventilation levels. It was found that carbon dioxide excretion and the rate of change of alveolar carbon dioxide tension were related to the alveolar ventilation.

Three exponential components were recognized in the carbon dioxide excretion curves and their time constants determined. These were related to the body stores from which carbon dioxide was removed.

The slope of the whole body carbon dioxide dissociation curve was found to be related to the alveolar ventilation level and ranged from 1·17–2·03 ml./mm. Hg./min,
SYMPATHETIC SECRETORY INNERVATION OF THE RAT'S SUBMAXILLARY GLAND
Authors: Ohlin P.
Published: December 2014

A supersensitivity to noradrenaline and a decrease in the size of the submaxillary gland of rats develops after preganglionic sympathetic denervation. Milk or a solution of citric acid given to conscious rats evokes a lively secretion from the normally innervated submaxillary gland; even after parasympathetic denervation a secretory response is elicited which disappears after sympathetic denervation. The present findings indicate that the sympathetic innervation of the rat's submaxillary gland has a secretory function.
STUDIES UPON THE RELATIONSHIP BETWEEN BARORECEPTOR AND SYMPATHETIC ACTIVITY
Authors: Green J. H. , Heffron P. F.
Published: December 2014

Simultaneous recordings of sympathetic activity in the right inferior cardiac nerve, and of baroreceptor activity in the common carotid baroreceptor nerve were made in cats with an isolated common carotid artery and sinus area.

The effect of the change from non‐pulsatile to pulsatile sinus pressure was to impose a rhythm synchronous with the pump upon sympathetic activity. The changes in amplitude of sympathetic activity were investigated.

The inhibition of sympathetic activity by carotid traction was used to identify sympathetic fibres.

The baroreceptor‐sympathetic reflex delay was of the order of 200 m/sec. thus providing a beat to beat control of cardiac activity.
COLLAGEN FORMATION AND CHANGES IN CELL POPULATION IN THE RAT'S UTERUS AFTER DISTENSION WITH WAX
Authors: Cullen Beulah M. , Harkness R. D.
Published: December 2014

Injection, through the cervical canal, of wax into the lumen of the uterine horn of spayed rats treated with a mixture of ostradiol‐17β, progesterone and relaxin, produced an increase in the total collagen content of the horn (estimated by determination of hydroxyproline). This occurred as a later phenomenon in a general growth process, accompanied by increase in the weight of the horn and cell division. Counts of the proportion of nuclei in mitosis after a single injection of wax showed increase within 24 hr., subsiding in 4 days. Estimates of total numbers of nuclei in the horn were also made in sections of fixed material from undistended and distended horns 4 days after a single injection of wax. Significant increase was found in epithelial and connective tissue cells of the endometrium and in muscle cells. The following estimates (in millions) were obtained for nuclear populations of undistended horns; luminal epithelium, 6; glandular epithelium, 2·5; endometrial connective tissue, 39; other connective tissue, 100; circuilar muscle, 34; longitudinal muscle, 29; granulocytes, 5.
THE MEASUREMENT OF HEAT LOSS FROM THE RAT'S TAIL
Authors: Little R. A. , Stoner H. B.
Published: December 2014

A simple method is described for measuring variation in the rate of heat loss from the tail of unanæsthetized rats with Hatfield‐Turner heat flow discs. The method was tested by giving l‐isoprenaline to adult rats acclimated to 20 or 3° C. The thermogenic response to this drug at an ambient temperature of 20° C. was increased four‐fold by cold‐acclimation. At 20° C. both the ‘resting’ and maximum rates of heat loss from the tail were greater in the 3° C. acclimated rats. The rate of heat loss from the tail increased abruptly to its maximum when the colon temperature reached a critical level of about 39·2° C. This response to l‐isoprenaline was not part of a general vaso‐dilatation diie to the drug.
THE FAILURE OF RESPIRATION IN DEATH BY TETRODOTOXIN POISONING
Authors: Cheng Kwok‐Kew , Ling Yen‐Lip , Wang James Chi‐Ching
Published: December 2014

After intravenous injection of tetrodotoxin in a dose which led to respiratory failure in the rat, the phrenic nerve continued to convey massive bursts of nerve impulses from the medullary centre for some time after cessation of respiratory movement, contraction of diaphragm and diaphragmatic muscle action potentials. In artificially ventilated intact rats the contractile response of a hemidiaphragm to indirect and direct stimulation diminished and disappeared together when tetrodotoxin was injected intravenously. In curarized rats, the response to direct stimulation disappeared when tetrodotoxin was given. In artificially ventilated rats which had one phrenic nerve cut 2 months previously, the contractile response of the denervated hemidiaphragm to direct stimulation and that of the intact opposite hemidiaphragm to indirect stimulation both diminished and stopped after the administration of tetrodotoxin. Action potentials were elicited from the biceps brachii muscle and its motor nerve following stimulation of the motor cortex; after injection of tetrodotoxin, both nerve and muscle action potentials diminished and disappeared together. It appears from the evidence presented that the failure of respiration in tetrodotoxin poisoning is due to paralysis of the respiratory muscles which were apparently more susceptible to the action of tetrodotoxin than the respiratory and other motor nerves or the non‐respiratory striated muscles.
URINARY EXCRETION OF BETA‐HYDROXYBUTYRATE AND ACETOACETATE DURING EXPERIMENTAL KETOSIS
Authors: Galvin R. Dennis , Harris Janet A. , Johnson Robert E.
Published: December 2014

Acetoacetate and beta‐hydroxybutyrate in blood and urine have been studied in experimental ketosis produced in healthy young men and women by: (a) exercise in the post‐absorptive state, (b) starvation and exercise, or (c) a high‐fat, low‐carbohydrate diet. With an increasing severity of ketosis, the plot of rate of excretion of acetoacetate against its concentration in the blood was a straight line, whereas the plot of the rate of excretion of beta‐hydroxybutyrate against its concentration in the blood was exponential. The two ketone bodies had a constant ratio in the plasma, but, as ketosis progressed, beta‐hydroxybutyrate became the preponderant molecule in the urine. The renal clearances of both acetoacetate and beta‐hydroxybutyrate were much lower than that for creatinine.
EFFECTS OF SELECTIVE MYOCARDIAL INACTIVATION ON LEFT VENTRICULAR FUNCTION DURING THE ISOVOLUMETRIC PHASE OF SYSTOLE
Authors: Taylor D. E. M. , Wade J. D. , Shishodia M. S. , Hider C. F.
Published: December 2014

The pressure changes in the left ventricle during the isovolumetric phase of systole have been studied in the dog before and three months after selective inactivation of between 5 per cent and 8 per cent of left ventricular myocardium. In fourteen animals the anterior papillary muscle was inactivated and in thirteen animals an equivalent mass of myocardium in the antero‐lateral wall of the left ventricle was inactivated. In both series left ventricular systolic pressure and mean cycle length were not significantly changed by the procedures. In the animals with lateral myocardial inactivation the mean left ventricular end diastolic pressure (LVEDP) was raised from 4·4 mm. Hg to 6·3 mm. Hg. The maximum rate of isovolumetric pressure rise was not significantly changed; it was 2530 mm. Hg/sec. initially and 2580 mm. Hg/sec. 3 months after inactivation. The mean time to reach the maximum rate of pressure rise was also unaffected, being 31 m/sec. initially and 30 m/sec. 3 months after inactivation. The first derivative of left ventricular pressure with respect to time was plotted; it was unchanged up to the peak rate of pressure rise (dP/dt max), apart from the higher LVEDP, but thereafter the curve showed a more rapid falling off. In the animals with papillary muscle damage the mean LVEDP was increased from 4·6 mm. Hg to 5·9 mm. Hg, (dP/dt) max fell from 2630 mm. Hg/sec. to 2020 mm. Hg/sec., and t(dP/dt)max lengthened from 29 m/sec. to 38 m/sec. All these changes were statistically significant. In the first derivative of pressure with respect to time the changes were seen as a fall in the peak value and a shift of the peak to the right. In six of the fourteen animals with papillary muscle damage mitral valve incompetence was produced. The changes in the isovolumetric portion of the pressure curve occurred whether or not mitral valve incompetence was present, but were accentuated when it was.

The contraction of the ventricle is a sequence of the contractions of its parts; the present results demonstrate that papillary muscle contraction is important early in thie seqcuence, at the start of the isovolumetric phase of systole.
THE PROJECTION OF THE RAT'S VISUAL FIELD ON THE CEREBRAL CORTEX
Authors: Adams A. D. , Forrester J. M.
Published: December 2014

The rat's visual field is represented on the cortex of each cerebral hemisphere within a primary visual area, visual field to the rat's right side upon the left hemisphere, and vice versa. The pattern of the representation has been determined electrophysiologically. The part of the visual field commanded by both eyes together, which is ahead of the animal, secures a larger representation upon the cortex in proportion to its size than the rest of the field, which is commanded by only one eye. There is evidence that a second smaller representation exists immediately lateral to the primary area.
FIBRINOLYTIC ACTIVITY IN ANIMALS OF DIFFERENT SPECIES
Authors: Irfan M.
Published: December 2014

Studies have been made on the activation of animal plasminogen in vitro and in vivo. Whole blood lysis times and euglobulin lysis times were determined for animals of different species. Dilution enhanced spontaneous lysis time of dog blood but not of cattle, horse, sheep and rabbit blood.

The dog blood contains proactivator and is activated by streptokinase. The initial streptokinase dose has been determined for dog blood in vivo. The blood of cattle, horses, sheep and rabbits was activated by urokinase which does not seem to require the presence of proactivator.

A tissue activator was present in the lymph nodes, kidneys, spleen and heart muscle but not in the liver of rabbits. Autographs from fresh frozen sections confirmed areas of fibrinolysis around the blood vessels, especially in the region of capillaries and small veins.

Two dogs on chlorpropamide showed a temporary increase in fibrinolytic activity and later developed resistance to the drug. Chlorpropamide had no fibrinolytic effect in rabbits.
ACTION OF SOME THIAMINE ANTAGONISTS ON FROG TASTE RECEPTORS
Authors: Perri V. , Rapuzzi G. , Sacchi O.
Published: December 2014

The influence of some thiamine antagonists (pyrithiamine and oxythiamine) on the response of frog taste receptors to chemical stimulation was studied. Isolated frog tongue preparations were perfused through the lingual artery with Tyrode solutions containing different amounts of pyrithiamine or oxythiamine. Pyrithiamine strongly depresses tongue receptor response to chemical stimulation. Its action however can be almost completely prevented by equimolar amounts of thiamine. Conversely oxythiamine does not affect taste receptor function even when perfused in elevated concentrations.

These results are interpreted as a proof that thiamine is essential in frog's taste receptor activation. The lack of any action of oxythiamine can be explained by considering that this substance acts as cocarboxylase antagonist only when phosphorylated and that it cannot be easily phosphorylated in vivo. Pyrithiamine, on the other side, is known to interfere with the phosphorylation of thiamine. On this basis it is suggested that thiamine may be involved in its phosphorylated form in taste receptor function.
THE EFFECT OF ENVIRONMENTAL TEMPERATURE ON HEALING OF BONE LESIONS IN THE RAT. I. EFFECT OF ENVIRONMENTAL TEMPERATURE ON MINERAL METABOLISM
Authors: Cuthbertson D. P. , Tilstone W. J.
Published: December 2014

The reduced food intake of rats living at 30° C. environmental temperature and relative humidity 22 per cent, compared to that of controls at 20° C. is reflected in a corresponding reduction in calcium turnover. This is shown by a greater whole‐body retention of an injected tracer dose of 85Sr by the rats living at the higher temperature and concomitant slower clearance from blood. When animals at the two environmental temperatures were fed equal amounts of food then the whole‐body retentions of tracer were the same in each group. Mechanisms discriminating against strontium are apparently not thereby involved.
ON THE PRESENCE OF GLUTAMINASE IN MUSCLE
Authors: Ottaway J. H.
Published: December 2014

The glutaminase activity of rat cardiac and skeletal muscle has been investigated, and compared with that of rat kidney. Vmax per g. of protein was 42 µmole/hr for heart muscle homogenates and 478 µmole/hr for kidney homogenates. Glutaminase activity was not detectable in about 50 per cent of the skeletal muscle homogenates; in the other 50 per cent the mean activity was about 30 µmole/g. protein/hr. The apparent Km of the enzyme in all 3 tissues was approximately 4 mM.

Bovine growth hormone injected into rats for 5 days did not alter the level of glutaminase activity in kidney or cardiac muscle, but significantly increased the percentage of skeletal muscle homogenates in which glutaminase was detectable.
IDENTIFICATION OF CORTICAL CELLS PROJECTING TO THE DORSAL COLUMN NUCLEI OF THE CAT
Authors: Gordon G. , Miller R.
Published: December 2014

Neurones projecting from cerebral cortex to dorsal column nuclei in the cat were identified by stimulating their axons in these nuclei and recording antidromic responses of individual cell‐bodies in the cortex. Latencies of response for 42 such neurones gave conduction velocities between about 3 and 20 m./sec. Corticogracile neurones were found medially and corticocuneate neurones laterally in the sensorimotor region; and histological identification of recording sites for 24 cells showed that most lay in area 3a. Hair‐sensitive skin receptive fields were found for 2 cells, and less well‐defined skin excitation for 5 others: the skin area corresponded to the region served by the nucleus to which the individual cell projected. Ten corticonuclear cells tested were shown to be independent of the corticospinal tract.
THE MECHANISM OF FAT ABSORPTION IN THE BILE FISTULA RAT
Authors: Morgan R. G. H. , Borgström B.
Published: December 2014

Fat absorption was studied in normal and bile fistula rats using test meals of corn oil containing radioactively labelled triolein. Two types of test meal were used, which would produce differently labelled monoglyceride and fatty acid under the action of pancreatic lipase.

Triolein containing 3H labelled oleic acid in the 1 and 3 positions and 14C labelled oleic acid in the 2 position was fed to normal and bile fistula rats with and without lymph fistulae. Short term pancreatic lipolysis of this triolein produced 3H labelled fatty acid and 14C labelled 2‐monoolein. Fat balance studies, Cori type experiments and the recovery of label in the lymph showed that in bile fistula rats 3H was absorbed in excess of 14C during the first few hr after feeding. In contrast, in lymph fistula rats with a normal bile flow 14C was absorbed in excess of 3H except in the earliest sample. These results indicate that after digestion triglyceride is absorbed mainly as fatty acid in the bile fistula rat, but as a mixture of fatty acid and monoglyceride in the normal animal. Analysis of lymph lipids confirmed that the mechanism of absorption is different in the bile fistula and normal animals.

A mixture of triolein labelled with 3H in the glycerol moiety and triolein labelled with 14C in the fatty acid moieties was also used as a marker in corn oil test meals fed to lymph fistula rats with and without bile diversion. In bile fistula rats the early lymph samples contained more 3H than 14C, but from 6 hr onward 14C predominated, and overall more 14C than 3H was recovered in the lymph. It seems probable that the early high recovery of 3H was due to the incorporation of free glycerol into lymph lipids in these animals. The overall recovery of 14C in excess of 3H is consistent with the concept that triglyceride is absorbed chiefly as fatty acid in the absence of bile. In animals with a normal bile flow 14C was absorbed in excess of 3H throughout the recovery period.

It is concluded that the mechanism of fat absorption in the bile fistula rat is not the same as it is in the presence of bile. Possibly fatty acid may be absorbed as soaps in the absence of bile, but no mechanism for the absorption of intact monoglyceride by these animals can be suggested.
AN INVESTIGATION OF THE NERVE SUPPLY TO THE SALT GLAND OF THE DUCK
Authors: Ash R. W. , Pearce J. W. , Silver Ann
Published: December 2014

Secretion can be produced from the salt gland of the duck by electrical stimulation of nerves reaching the gland and by the administration of parasympathomimetic drugs; the latency of this response is similar to that of the secretory response produced by intravenous salt loading and is similarly inhibited by atropine. The salt gland contains both acetyl‐ and butyrylcholinesterase; the former appears to be associated with nerve fibres which originate in cells occurring along the gland's secretory nerve and in its ganglion. There is no obvious difference in cholinesterase content of secreting and resting glands. Denervation of the salt gland, by an operation which includes removal of the ganglionic portion of the secretory nerve, abolishes secretory response to salt load and leads to disappearance of cholinesterase. Such denervated glands may be caused to secrete by administration of carbachol; this response is potentiated by concurrent salt loading. Section of the secretory nerve central to its ganglionic region, however, fails to abolish secretion in response to salt loading and does not alter cholinesterase content. Hexamethonium in large doses fails to influence the establishment or course of a secretory response to salt loading. These findings, coupled with the demonstration that cholinesterase staining in the secretory nerve is only seen in and distal to its ganglion cells, suggests that the cholinergic nerve supply to the gland is unusual. The findings support the concept that a cholinergic secretomotor mechanism can produce salt gland secretion. They also imply that any associated hormonal control of secretion cannot operate in the absence of intact peripheral nerve supply. The possibility is discussed that the ganglion cells of the secretory nerve may have an osmoreceptive function.
OBSERVATIONS ON THE ELIMINATION RATES OF SINGLE INJECTIONS OF TAUROCHOLATE AND CHOLATE IN THE DOG
Authors: O'Máille E. R. L. , Richards T. G. , Short A. H.
Published: December 2014

Single intravenous injections of taurocholate were eliminated in the bile more rapidly than those of cholate in the anæsthetized dog in which the common bile duct had been cannulated. The time taken for the first 50 per cent of the total biliary excretion (T 50 per cent ex.) was measured. For taurocholate it was 12·7 ± 1·2 (S.D.) min and for cholate 18·9 ± 1·8 min. About four‐fifths of injected cholate appeared in bile conjugated as taurocholate, the remainder as free cholate. Each bile salt was given as a dose of 0·12 m‐mole/kg body wt; at twice this dosage the mean T 50 per cent ex. for taurocholate was 14·2 min and for cholate was 25·5 min. Taurocholate was also eliminated more rapidly than glycocholate. The delay in excretion of cholate is probably due to (a) the extra time necessary for its conjugation with taurine in the liver before excretion, (b) the extra time required for the transfer of the remainder of the dose as free cholate, whose excretion is less efficient than that of taurocholate, and (c) the fact that cholate appears to gain entry to a wider distribution space than taurocholate, and hence proportionately less is presented to the liver in unit time for removal. After the first 5‐10 min from completion of the injection the disappearance of taurocholate from plasma was also more rapid than that of cholate. The fraction of bile salt removed in a single passage through the liver, determined at 5 min intervals after injection, was lowest for the first 5 min calculation and thereafter progressively increased. The extraction fraction for cholate was always less than that for tauro‐ and glycocholate; for the latter two it reached a value of over 95 per cent by 15‐20 min.
PLASMA CORTICOSTERONE IN THE RAT IN RELATION TO TRAUMA AND ENVIRONMENTAL TEMPERATURE
Authors: Tilstone W. J. , Roach P. J.
Published: December 2014

Male Wistar rats show a marked rise in plasma corticosterone 1 hr after fracture of a femur under halothane‐oxygen anaesthesia when they are housed at 200° C. or at 30° C. Anaesthesia alone produces a less marked response. No elevation is seen 6 hr after fracture or anaesthesia alone at 200° C.

The animals were handled frequently and blood taken from unhandled animals gave results for plasma corticosterone about three times higher than handled controls.

Controls, and animals only anaesthetized, had lower plasma corticosterone levels at 30° C. than at 200° C.; but there was no such difference between the animals undergoing fracture at 200° C. and those at 300° C.
EFFECT OF XANTHINOL NICOTINATE ON THE SURVIVAL RATE OF DOGS SUBJECTED TO ACUTE BLOOD LOSS
Authors: Sharma P. L.
Published: December 2014

The effect of xanthinol nicotinate (10 mg/kg i.v.) on the survival of dogs subjected to acute blood loss was investigated. The arterial blood pressure was reduced to 35 mm Hg by rapid arterial bleeding and maintained there for 4 hr. The shed blood was then returned to the animals. In the control group, only one out of ten dogs survived, and all developed severe diarrhoea. With xanthinol nicotinate given beforehand, five out of ten dogs survived, and three developed mild diarrhoea. When the drug was given 2 hr after the onset of hypotension six out of ten dogs survived, and five developed mild diarrhoea. When xanthinol nicotinate was given 4 hr after the onset of hypotension, eight out of ten dogs survived. Severe diarrhoea developed in all the dogs. Xanthinol nicotinate did not produce any persistent change in arterial pressure even in the presence of hypovolaemia. The mechanism of its effect and its possible usefulness in man are discussed.
INTERRELATION OF RESPONSES DURING PROGRESSIVE EXERCISE IN TRAINED AND UNTRAINED SUBJECTS
Authors: Edwards R. H. T. , Jones N. L. , Oppenheimer E. A. , Hughes R. L. , Knill‐Jones R. P.
Published: December 2014

In twelve cyclists (‘trained’ group) and twelve sedentary subjects (‘untrained’ group) the cardiovascular, pulmonary and metabolic responses to submaximal cycle ergometer exercise have been investigated. Lower values for ventilation (VE), heart, rate (HR), cardiac output (VQ), respiratory exchange ratio (R) and blood lactate (La) were found in the trained group. When related to oxygen intake as percentage of predicted maximum the responses of VE, HR and Q were similar in the two groups but values for La remained lower in the trained subjects. It was concluded that a more rapid and more efficient distribution of cardiac output occurred in the trained group.

Five ‘trained’ and four ‘untrained’ subjects were studied during maximal work. Similar values for Q, HR and La were found in both groups; VE was higher and constituted a significantly higher proportion of the ventilatory capacity (sustained M.V.V.) in the trained compared with the untrained group (81 per cent and 66 per cent respectively). In both groups the rate at which ventilation increased as maximal loads were approached may have led to a ventilatory limitation to further work.
A SEASONAL CHANGE IN THE DIURNAL RHYTHM OF THE EXCRETION OF 3‐METHOXY‐4‐HYDROXYMANDELIC ACID IN MAN
Authors: Davies T. W.
Published: December 2014

In two series of experiments, one in the autumn and one in the winter on an Antarctic base, diurnal rhythms have been demonstrated in the urinary excretion of V.M.A. These persisted in spite of changes in the hours of daylight. There was a small rise in the total amount of V.M.A. excreted in winter, and an increase in the amplitude of the diurnal rhythm which was significant for one 4‐hr period of the day. However, in general, the diurnal rhythms were very similar. The most likely causes of the rise ‐ environmental temperature change, mood changes and alterations in posture ‐ do not appear to have been responsible. Possible long‐term changes, such as an increased response of the sympathoadrenal system to similar amounts of cold, i.e. cold acclimatization, cannot be dismissed.
RECEPTIVE FIELD PROPERTIES OF SINGLE UNITS FROM THE VISUAL PROJECTION TO THE IPSILATERAL TECTUM IN THE FROG
Authors: Gaze R. M. , Keating M. J.
Published: December 2014

The receptive field characteristics of single visual units in the ipsilateral tectum of the frog were investigated. In contrast to units in the contralateral tectum, ipsilateral units all responded to small visual stimulus objects and gave a sustained response to a small stationary black disk. Inhibition of this sustained response by a moving edge some distance from the ERF could be demonstrated and was more marked than with contralateral units. Some of the deeper ipsilateral units, in addition to the properties already mentioned, were excited by decremental dimming of the background illumination. The type of behaviour known as ‘changing contrast detection’ (class 3 units) in the contralateral tectum was not found ipsilaterally.
VAGAL DEFLATION AND INFLATION REFLEXES MEDIATED BY LUNG IRRITANT RECEPTORS
Authors: Sellick Hilary , Widdicombe J. G.
Published: December 2014

Lung irritant receptors in anaesthetized rabbits are stimulated by deflations and large inflations of the lungs, with irregular and rather rapidly adapting discharges. After deflation the spontaneous discharge of the receptors is increased, and dynamic compliance is decreased. After inflation the spontaneous discharge is decreased, and compliance is increased. The responses of the receptors to inflation and deflation and the relationship with compliance suggest that they are part of the vagal reflex mechanism stimulating breathing or inspiratory activity in these conditions.
STUDIES ON THE IN VITRO FORMATION OF MONOIODOTYROSINE BY SOLUBLE SUPERNATANT OF PIGEON THYROID GLAND
Authors: Bhattacharya Samir , Datta Asoke G.
Published: December 2014

A soluble supernatant preparation of pigeon thyroid gland can catalyse the iodination of tyrosine to monoiodotyrosine in vitro. The enzyme needs a hydrogen peroxide generative system such as glucose and glucose oxidase or Cu2+ for its activity. The optimum concentration of Cu2+ was found to be 1·33 x 10−3 M. Direct and slow addition of hydrogen peroxide cannot be substituted for Cu2+.

Antithyroid agents like thiourea and thiouracil are found to be more potent inhibitors of avian enzyme than of mammalian enzyme. Ascorbic acid inhibits the enzyme but stimulates remarkably when a dialysed enzyme is used instead of an undialysed one.
INTRACELLULAR pH IN MATURE AND IMMATURE RABBIT RED CELLS
Authors: Calvey T. N.
Published: December 2014

The intracellular pH of rabbit red cells was determined from the distribution of (2‐14C) DMO. Evidence is presented that the method provides a valid estimate of intracellular pH. In phosphate buffer at pH 7·40, the mean intracellular pH of the rabbit erythrocyte was 7·27. There was a close correspondence between the distribution ratios for hydrogen and chloride ions in normal rabbit blood. Values for intracellular pH, based on forty experiments in normal animals, were consistent with recent measurements of the membrane potential of mammalian red cells.

The intracellular pH of the reticulocyte was deduced from the effect of acetylphenylhydrazide on the internal pH of rabbit red cells. At an external pH of 7·40, mean reticulocyte pH (7·32) was 0·06 pH units higher than mean erythrocyte pH (7·26).

In preparations of reticulocytes, the distribution ratio for chloride ions was lower than the corresponding ratio for hydrogen ions. It is suggested that the presence in reticulocytes of small numbers of relatively alkaline mitochondria may be responsible for this phenomenon.
SOME PHYSIOLOGICAL ASPECTS OF ALPHA AMINO NITROGEN METABOLISM IN THE UTERUS OF THE PREGNANT AND NON‐PREGNANT EWE
Authors: Curet Luis B. , Crenshaw Carl , Mann Leon , Abrams R. H. , Barron D. H.
Published: December 2014

Arterial and uterine venous concentrations of alpha amino nitrogen and uterine blood flow were repeatedly measured in twelve non‐pregnant and ten pregnant Dorset ewes.

The arterial levels and uterine arteriovenous differences of alpha amino nitrogen were low early in gestation and gradually increased to approach non‐pregnant values towards the end of gestation. The uterine uptake of alpha amino nitrogen per kilogramme of uterine tissue behaved in a similar way but remained lower than the uptake per kilogramme of tissue by the non‐pregnant uterus.

The data suggest that the removal of amino acids by the uterus is independent of the levels in the blood reaching the organ.
THE EFFECT OF GLUCAGON ON PLASMA CALCIUM ION ACTIVITY IN THE MONKEY
Authors: Raman A.
Published: December 2014

Using a newly developed calcium‐sensitive electrode, the effect of glucagon on the plasma ionic calcium in monkeys was investigated. It was observed that the hormone causes a significant depression of both the total and ionic calcium levels.
RENAL TUBULAR REABSORPTION OF UREA IN SHEEP
Authors: Scott D. , Mason G. D.
Published: December 2014

Renal tubular reabsorption of urea was studied in sheep fed diets containing either 2·7 or 0·88 per cent nitrogen but which were equal in the proportions of roughage to concentrate components and in energy.

As the amount of urea filtered at the glomerulus increased through the range 54–1347 µmole/min the amount reabsorbed by the tubule increased proportionately. This relationship was not influenced by urine flow rate within the range 1·0–9·2 ml./min. At urine flow rates less than 1·0 ml./min percentage reabsorption of filtered urea increased as urine flow rate diminished, an effect which was more marked when the low‐N diet was fed compared to when the high‐N diet was fed. This difference did not appear to be related to differences in the absolute amount of urea filtered but rather to differences in nitrogen intake or metabolism. The mechanism by which reabsorption is increased is as yet uncertain.
EFFECT OF SECRETIN ON BILE FORMATION IN SHEEP
Authors: Heath Trevor
Published: December 2014

The rate of flow of bile increased rapidly when pure natural secretin was infused into the portal vein of conscious, standing sheep. The increment in flow was related significantly to the logarithm of the rate of administration but was not affected by the simultaneous infusion of sodium taurocholate into the portal vein. When secretin and taurocholate were given together the rate of flow of bile was five times that during the control period of bile salt deprivation. Secretin stimulated the secretion of total fatty acids into the bile of sheep when they were deprived of recirculated bile salts and also when they received an infusion of taurocholate into the portal vein. The mean maximum rate of total fatty acid secretion was 38 per cent higher during infusion of secretin with taurocholate than during infusion of taurocholate alone. When taurocholate was infused into the portal vein at 37 µumole/min or less, it was transferred quantitatively into the bile, and secretin did not appear to affect this process. However, when taurocholate was infused alone at 112 µmole/min it was not transferred quantitatively into the bile, but the efficiency of this transfer was increased by the simultaneous infusion of secretin. The concentration in the bile of total fatty acids and of bile salts decreased during infusion of secretin, but no significant changes occurred in the concentration of sodium. The infusion of secretin caused no significant changes in the osmolality of the bile in five sheep, but in three experiments on a sixth sheep it caused a highly significant increase in osmolality. When secretin was infused into the portal vein, no changes occurred in the arterial pressure, pulse rate, portal venous pressure or respiratory rate. These experiments indicate that secretin could play a significant role in regulating bile secretion in the sheep.