bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF PROTAMINE ZINC INSULIN ON WEIGHT GAIN AND FAT DEPOSITION IN THE JUVENILE DOMESTIC DUCK
Authors: Evans A. J.
Published: December 2014

Contrary to the findings in mammals, prolonged treatment with protamine zinc insulin did not increase the rate of weight gain in the juvenile duck. Higher levels of this hormone retarded growth, lowered food intake and produced a substantial hypoglycaemia. No change in fat content or distribution was produced by the insulin treatment. Production of antibodies to exogenous insulin was rare and unlikely to neutralize the action of this hormone.
UTERINE BLOOD FLOW AND OXYGEN CONSUMPTION IN THE UNRESTRAINED PREGNANT EWE
Authors: Huckabee William E. , Crenshaw M. Carlyle , Curet Luis B. , Barron Donald H.
Published: December 2014

The rates (ml./kg/min) of uterine blood‐flow and of oxygen consumption have been estimated in pregnant ewes at known stages in gestation; the ewes were unrestrained and the circumstances were known to be compatible with fetal survival and growth. The two rates appear to vary independently and predictably during the course of gestation. Prior to the 66th day of gestation (full term 145–147 days) the mean rate of blood flow was 513·2 ml./kg/min and of the oxygen consumption of the uterus and its tissue contents 5·0 ml./kg/min; the corresponding values for the period 90 days to full term were 248·1 and 10·4 ml./kg/min respectively.
THE EFFECT OF GLUCOSE, GALACTOSE AND SORBITOL ON GASTRIC EMPTYING IN THE YOUNG PIG
Authors: Reed J. H. , Kidder D. E.
Published: December 2014

The emptying times of glucose solutions of different concentrations by the stomach of the young pig have been compared. The emptying of glucose solutions has also been compared with that of galactose, sorbitol and sodium chloride of similar osmolarity.

The more concentrated the glucose solution, the more slowly it is emptied, as is reported in other species. The emptying rate of galactose is similar to that of glucose and slower than sorbitol which is emptied at a similar rate to sodium chloride.
MEASUREMENT OF CARBON DIOXIDE PRODUCTION IN SHEEP BY ISOTOPE DILUTION
Authors: Whitelaw F. G. , Brockway J. M. , Reid R. S.
Published: December 2014

Sheep were given continuous subcutaneous infusions of NaH14CO3 at a rate of 0·03 ml./min, 90–150 nCi/min, for periods of 8 to 36 hr and the rate of entry of metabolic CO2 into the body pool of CO2 was calculated from the relationship between the rate of infusion of radioactivity and the specific activity (SA) of CO2 in blood or urine samples. In preliminary experiments, the variability from hour to hour in the SA of CO2 was found to be two to three times greater for blood than for urine samples and, in urine, was two times greater under a twice‐daily feeding regime than under continuous feeding conditions. An infusion period of about 8 hr was required for the initial equilibration of the infused activity with the body pool of CO2.

A close relationship was found to exist between CO2 entry rates derived from the SA of CO2 in samples of urine or expired air collected over 24 hr, and either total CO2 production or total heat production as measured in a closed‐circuit respiration chamber. On average, entry rate values calculated from urine samples overestimated total CO2 production by 3·7 per cent and those calculated from expired air overestimated by 2·2 per cent. The regression equations describing the relationships between CO2 entry rate and CO2 production or heat production had residual standard deviations ranging from 4·3 to 7·5 per cent of the mean values.

In sheep given two meals per day there was a reduction in the SA of CO2 in urine immediately after eating. Since feeding had no apparent effect on the rate of transfer of 14CO2 from rumen to urine it was concluded that the depression in SA resulted from a general increase in metabolic activity consequent upon the absorption of nutrients from the gut rather than from dilution with unlabelled CO2 produced in rumen fermentation. In certain sheep the postprandial depression in SA was very marked and appeared to be associated with a reduction in urine pH. Attempts to recreate this condition in penned sheep and to explain it by reference to changes in the acid‐base status of the blood were not entirely successful.
VARIATIONS IN ASPHYXIAL GASPING WITH FETAL AGE IN LAMBS AND GUINEA‐PIGS
Authors: Dawes G. S. , Fox H. E. , Richards R. T.
Published: December 2014

The time to the last gasp after tying the umbilical cord was measured in fetal lambs and guinea‐pigs of different gestation ages; body temperature was maintained. At two‐thirds of term the times to the last gasp were slightly but significantly greater than at full term in both species. But at about 0·34 (lamb) and 0·46 of term (guinea‐pig) the times to the last gasp were very much less than in mature fetuses.

In lambs a third of the way through gestation the short time to the last gasp could not be attributed to hypoglycaemia, circulatory collapse or neuro‐muscular failure. The results suggest that at this age the respiratory centre may be more susceptible to asphyxia, yet post‐asphyxial recovery occurred rapidly.
THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS
Authors: Draper M. H. , Davidson Maida F. , Wyburn G. M. , Johnston H. S.
Published: December 2014

The fibrous membrane forming region of the isthmus of the oviduct of Gallus Domesticus forms the upper two thirds of the anatomical isthmus. The secreting surface of the isthmus is arranged in a series of longitudinal ridges. The mucous membrane consists of a surface epithelium of columnar cells beneath which is a layer of tubular glands. In the membrane forming part of the isthmus the tubular gland cells are filled with prominent secretory granules, hence the name granular isthmus. The tubular glands of the lower third of the isthmus have few prominent granules and the region has a characteristic reddish tinge; hence the name red region of the isthmus is appropriate.

In the granular isthmus there are three types of surface epithelial cell. About half are ciliated cells. These have nuclei situated towards the apex of the cell and contain scattered electron dense granules, particularly towards the apex. Lysosome‐like bodies are also present. Alternating with the ciliated cells are secretory cells termed granular cells which tend to bulge out of the surface to form blebs which are filled with aggregations of granules which are usually electron dense. This material is PAS positive and alcian blue negative in histological preparations. The nuclei are situated basally and they are usually associated with granular endoplasmic reticular (GER) profiles and cisternae filled with homogeneous material. Golgi substance is not prominent. Some cells contain masses of small granules morphologically resembling glycogen particles. A third type of cell constitutes about 8% of the surface epithelium. It contains columns of mitochondria running from the base to the apex of the cell. There are no cilia or secreting granules present, yet the apex bulges above the mucosal surface. The function of these mitochondrial cells is obscure; there is no movement of water, Na+ or K+ into the granular isthmus lumen. The tubular gland cells are filled with secretory granules ranging from 0·2 µm to 3 µm. Most of the granules are of uniform electron density but granules with a wide variety of density pattere are seen. Microvilli are prominent as are mitochondria often associated with GER profiles. The GER profiles can be prominent and they have a remarkable beaded appearance due to an altemation of dense and pale areas. Golgi material is prominent and complex when it is visible in cells depleted of secretory material. The granules are not secreted as such. Amorphous material condenses into a membrane fibre in the lumen of a tubular gland and by the time these fibres reach the luminal surface of the oviduct they have the characteristic core and mantle structure of the basic fibre of the shell membrane.
THE EFFECT OF ACETYLSALICYLIC ACID ON PLATELET ADHESION IN THE INJURED ABDOMINAL AORTA
Authors: Sheppard B. L.
Published: December 2014

The effect of a single oral dose of acetylsalicylic acid (ASA) on platelet adhesion in the rabbit abdominal aorta following a standard mechanical removal of the endothelium has been observed with both the scanning and transmission electron microscopes, in conjunction with studies on the agglutination properties of the platelets in vitro. It was found that the ASA did not prevent adhesion of platelets to the subendothelial surface although they did not appear to be adhering to the exposed collagen fibres but rather to endothelial basement membrane and microfibrils of the internal elastic lamina, often in small clumps. A large number of leucocytes were also observed adhering to the surface denuded to endothelium.

The platelets obtained from ASA treated animals were morphologically normal, but unlike platelets obtained before treatment, did not adhere to collagen fibres in vitro; even when ADP was added the platelets adhered to one another but not to the collagen.
THE CARDIOVASCULAR EFFECTS OF CORONARY SINUS DISTENSION IN THE ANAESTHETISED DOG
Authors: Muers M. F. , Sleight P.
Published: December 2014

Experiments were carried out to determine whether the systemic hypotension caused by distension of the coronary sinus is reflex in origin. In anaesthetized open‐chest dogs, indwelling Morawitz balloon cannulae were used to distend the sinus. Eighty‐three distensions in fourteen experiments with intact vagi caused systemic hypotension and tachyeardia, but there was no significant change in this response in a further twenty‐two tests after the cervical vagi had been cut, or cooled (to less than 5°C). Recordings were made of sympathetic efferent nerve activity in few‐fibre preparations from the ventral ansae subelaviae. Activity was reduced during the hypotension reflexly caused by intrapericardial nicotine but was increased after coronary sinus distension. The increase in activity occurred both with intact and sectioned vagi. It was concluded that the excitation of cardiac mechanoreceptors in the coronary sinus wall by distension does not produce measurable reflex depression of the circulation, and that the hypotension observed after sinus distension is mechanically caused, rather than reflex in origin as earlier studies have implied.
ELECTRON MICROSCOPICAL OBSERVATIONS ON SHEEP UMBILICAL VESSELS
Authors: Sheppard B. L. , Bishop A. J.
Published: December 2014

A method for the preservation of the fine structure of the umbilical vessels, including the endothelium, is described. Electron microscopical observations have been made showing the presence of a metabolically active endothelium; the absence of an internal elastic lamina in the intima; the presence of longitudinally and circularly orientated smooth muscle cells; and well developed vasa vasorum in the media of the artery. The principal differences in the vein were the presence of an attenuated internal elastic lamina in the intima; the presence of circularly orientated smooth muscle cells and longitudinally orientated elastic fibres, and the absence of vasa vasorum.
THE USE OF SUGARS AND FLUORODINITROBENZENE (FDNB) TO DIFFERENTIALLY LABEL RED CELL MEMBRANE COMPONENTS INVOLVED IN HEXOSE TRANSFERS
Authors: Eady R. P. , Widdas W. F.
Published: December 2014

The possibility of differentially labelling human red cell membrane components involved in the facilitated transfer of hexoses by incubation with 1‐fluoro‐2,4‐dinitrobenzene (FDNB) irr the presence of different sugars, one with a potentiating effect on the inhibitory reaction and the other with a protective effect, has been explored.

After incubation with 14C‐FDNB, membrane proteins were subjected to SDS polyacrylamide gel disc electrophoresis and gel fractions were assessed for radioactive labelling. Early fractions from cells incubated with 2‐deoxyglucose (the potentiating sugar) carried more label than those from cells incubated with ethylidene glucose (the protecting sugar).

In both types of incubations the bulk of the label was taken up nonspecifically by intracellular material and membrane proteins but this technique and a method based on the preferential uptake of D‐glucose from a D‐/L‐glucose mixture point to fractions which merit further study by methods of increased resolving power.
THE EFFECT OF ISOPRENALINE ON THE CARDIAC AND RESPIRATORY RESPONSES TO EXERCISE
Authors: Silverman M. , Zeidifard E. , Paterson J. W. , Godfrey S.
Published: December 2014

The effects of intravenous isoprenaline on the response to exercise were studied in five normal adults. Each subject exercised on a bicycle ergometer at work loads of 50, 100, 150 watts. At each work load ventilation and gas exchange were measured; cardiac output and stroke volume were calculated using the Indirect (CO2) Fick method.

Isoprenaline produced no significant changes in oxygen consumption or in minute ventilation. Heart rate was significantly increased by isoprenaline in all subjects, the increment becoming smaller at higher workloads. In four of the subjects cardiac output was increased by isoprenaline, stroke volume being virtually unchanged. In the remaining subject cardiac output was unchanged with a fall in stroke volume.
CARDIAC FREQUENCY DURING SUBMAXIMAL EXERCISE IN YOUNG ADULTS; RELATION TO LEAN BODY MASS, TOTAL BODY POTASSIUM AND AMOUNT OF LEG MUSCLE
Authors: Cotes J. E. , Berry G. , Burkinshaw L. , Davies C. T. M. , Hall A. M. , Jones P. R. M. , Knibbs A. V.
Published: December 2014

The cardiac frequency and consumption of oxygen during submaximal exercise, lean body mass, total body potassium, thigh muscle width and an index of thigh muscle volume have been obtained for seventy‐nine healthy men and women, ages 18 to 38 yrs, who were not in athletic training but accustomed to taking some exercise. For these subjects, at any specified submaximal rate of consumption of oxygen, the cardiac frequency is negatively correlated with the indices of body muscle which are themselves inter‐correlated (r 〉 0·89). The latter relationships provide a basis for prediction of total body potassium (coefficient of variation 6·1 %). The relationship of exercise cardiac frequency to body muscle is similar in both men and women; it provides a better description of frequency than one based on consumption of oxygen alone (coefficient of variation respectively 12% and 18%). Cardiac frequency is independently related to the level of habitual activity of the subjects. The implications of these findings are discussed.
STIMULATION OF AFFERENT NERVE TERMINALS IN THE PERFUSED RABBIT LIVER BY SODIUM SALTS OF SOME LONG‐CHAIN FATTY ACIDS
Authors: Orbach J. , Andrews W. H. H.
Published: December 2014

Rabbit livers were perfused with Krebs solution and action potentials were monitored in bundles of the hepatic nerves. When the perfusion fluid contained myristate in a concentration of 0·03 mM or greater there was stimulation of some nerve fibres: oleate, laurate and palmitate stimulated when in greater concentrations, but hexoate was without effect. The effect of these fatty acids was tested on perfused rat hearts, perfused rabbit ears and on isolated rabbit small intestine both in the presence and absence of pharmacological agents which block the autonomic system or its chief transmitters. There was a direct effect on the myocardium but not on the other tissues and no evidence of release of acetylcholine or noradrenaline. In perfused livers the stimulatory action of the fatty acids appeared to be on some afferent but not on efferent nerves. Addition of plasma diminished or abolished the effect. The relevance of this study to events in vivo is not known but under certain conditions long‐chain fatty acids can undoubtedly stimulate some afferent nerves when in high dilution.
CHOLINE ACETYLTRANSFERASE IN THE HEART AND SALIVARY GLANDS OF THE RAT AFTER PHYSICAL TRAINING
Authors: Ekström J.
Published: December 2014

After physical training of rats for 11–14 weeks both weight of atria and weight of ventricles were higher in relation to body weight than those of untrained controls. The capacity to synthesize acetylcholine, as judged by the activity of choline acetyltransferase, was increased in the atria of the trained rats, but the enzyme activity did not change in the ventricles. This result seems to support the concept of a high cholinergic activity as one cause of the low resting heart rate after training.

Salivary glands are known to take part in thermo‐regulation in rats. After the period of training increased submaxillary gland weight was found in relation to bodyweight, but two other major salivary glands were unchanged. Although the training seems to have caused increased secretory activity of the submaxillary gland, no changes in the activity of choline acetyltransferase were noticed.
PHOSPHOPROTEIN BOUND IRON IN THE BLOOD PLASMA OF THE LAYING HEN
Authors: Ali K. E. , Ramsay W. N. M.
Published: December 2014

1. Plasma iron in the laying hen has been separated into two components by adsorption on magnesium carbonate, gel filtration and ion exchange chromatography. 2. The non‐transferrin component is closely associated with phosphoprotein. 3. There is no exchange of iron in vitro between the components, but in the living bird transferrin iron seems to be the precursor of the phosphoprotein iron.
FLOW DISTURBANCES IN GLASS MODELS OF ANEURYSMS AT LOW REYNOLDS NUMBERS
Authors: Stehbens W. E.
Published: December 2014

Flow in glass models, simulating fusiform, cylindrical, spherical and lateral saccular aneurysms, was examined by experimentation using the dye injection technique. Aneurysmal dilatations on straight tubes did not induce turbulence at Reynolds numbers below the critical level for turbulence in a straight tube (2000). A lateral aneurysm associated with a deflection of the distal tube (20°) induced turbulence distal to the aneurysm at a Reynolds number of 1100.

In all models, waves in the dye within the aneurysm and in the parent tube immediately distal to the aneurysm were observed at Reynolds numbers considerably below critical levels for turbulence. This wave motion, due to oscillations of the dye filaments at the junction of the tube and the distal end of the aneurysm, is possibly a jet edge phenomenon.
AEROBIC WORK CAPACITY IN YOUNG, UNTRAINED ASIAN WOMEN
Authors: Duncan M. T. , Chan K. Y.
Published: December 2014

Cardiorespiratory adjustments to maximal exercise on a bicycle ergometer were studied in a group of young, untrained Asian women. Maximal oxygen uptake averaged 1·381 ± 0·07 (SE) l./min; 28 ± 1·3 (SE) ml./min/kg and maximal cardiac output 14·6 ± 0·8 (SE) l./min. Other related respiratory and circulatory functions were also measured. These values were comparable to those reported for similar population groups of the West when body size was taken into consideration.
CHOLINE ACETYLTRANSFERASE ACTIVITY IN RAT SALIVARY GLANDS AFTER CELLULOSE RICH DIET OR TREATMENT WITH AN ATROPINE‐LIKE DRUG
Authors: Ekström J.
Published: December 2014

When rats are fed on dry, cellulose rich diet the choline acetyltransferase activity of the parotid gland increases, provided the auriculo‐temporal nerve is intact. Dryness of the oral mucosa produced by atropinization is also followed by an increase in enzyme activity of the gland. It is suggested that the increased activity of the acetylcholine‐synthesizing enzyme is due to enhanced traffic of secretory impulses in the para‐sympathetic nerves to the gland, reflexly elicited by the two kinds of treatment.
THE METABOLIC EFFECTS OF STRENUOUS EXERCISE: A COMPARISON BETWEEN UNTRAINED SUBJECTS AND RACING CYCLISTS
Authors: Rennie M. J. , Jennett Sheila , Johnson R. H.
Published: December 2014

Previous investigations have suggested that post‐exercise ketosis is more marked in untrained subjects than in athletes. The present study was designed to exclude the possibility that the untrained subjects worked relatively harder. Four racing cyclists and five untrained subjects were studied during and after 20 min strenuous exercise on a bicycle ergometer. The work loads were adjusted so that the cyclists worked at least as hard, in terms of the heart rate attained, as the untrained subjects. Observations were made of respiratory gas exchange; blood samples were taken at rest, during and after the exercise and were analysed for ketone‐bodies and other metabolites, insulin and growth hormone.

The racing cyclists worked at 1070 kpm/min with heart rate of 179·5 beats/min and oxygen consumption of 48 ml./min per kg body‐weight (means). The values for the untrained subjects were 715, 167 and 35 respectively. After exercise the concentration of ketone‐bodies in the blood increased progressively in both groups, reaching highest measured values 150 min after exercise. The increase was much smaller for all the racing cyclists. We conclude that post‐exercise ketosis is less in athletes even when they work as hard as or harder than untrained subjects.
EFFECTS OF CROSS‐INNERVATION ON THE MOTOR END‐PLATES OF FAST‐ AND SLOW‐TWITCH MUSCLES OF THE RABBIT
Authors: Dias P. L. R. , Simpson J. A.
Published: December 2014

The surface areas of vitally stained motor end‐plates in normal, cross‐ and self‐innervated fast‐twitch and slow‐twitch skeletal muscles of the rabbit hind limb were measured. The normal slow‐twitch soleus muscle contained motor end‐plates which had a mean surface area significantly larger than those in the ‘fast’ FDL. After cross‐innervation the nerve to soleus forms larger end‐plates on the FDL muscle and its twitch becomes slower, while the FDL nerve forms smaller end‐plates on the soleus muscle and the soleus twitch becomes faster. There is, however, no complete reversal of end‐plate size or of twitch characteristics, but the areas of the end‐plates and the contraction times tend to be intermediate between the two normal types of muscle. The findings suggest that the size of a motor end‐plate is not governed by the type of muscle fibre but by the motoneurone and that the end‐plate area is closely linked with the twitch characteristics of the muscle fibre.
THE EFFECT OF EXOGENOUS PROGESTERONE ON THE RATE OF BLOOD FLOW OF THE UTERUS OF OVARIECTOMIZED SHEEP
Authors: Caton D. , Abrams R. M. , Clapp J. F. , Barron D. H.
Published: December 2014

Progesterone was administered to fifteen ovariectomized non‐pregnant sheep in order to observe its effect on the rate of uterine blood flow (ml./kg/min), and on the relationship between these rates of flow and metabolism, as reflected in estimates of the arteriovenous oxygen difference and the uterine cavity‐aortic blood temperature difference. No effects were observed when only progesterone was administered, but when progesterone was given to ewes already receiving oestrogens, the rate of uterine blood flow fell and coefficient of oxygen utilization and temperature difference increased. The possible significance of these observations to cyclical changes observed during the oestrous cycle is discussed.
SPLANCHNIC MECHANORECEPTORS IN THE DOG
Authors: Floyd K. , Morrison J. F. B.
Published: December 2014

Single unit recordings from the splanchnic nerve of the dog have demonstrated the presence of Aδ and C fibres which respond to mechanical stimuli. The units gave tonic discharges in response to maintained mechanical stimuli and the majority had punctate mechanosensitive sites which occurred at vascular divisions. The receptive fields consisted of between one and eight such mechanosensitive sites. Mechanoreceptors have been found in the body and antrum of the stomach, duodenum and/or pancreas, spleen, greater and lesser omenta, small intestine, ascending and transverse colon, mesenteric root, pre‐renal area and ovary.
ELASTIC FIBRES AND RETICULIN OF MAMMALIAN MUSCLE SPINDLES AND THEIR FUNCTIONAL SIGNIFICANCE
Authors: Cooper Sybil , Gladden Margaret H.
Published: December 2014

The distribution of elastic fibres and reticulin of muscle spindles of man, cat and rat was studied by light and electron microscopy. The elastic fibres form a continuous network, arranged longitudinally around the intrafusal fibres; this is connected to a much finer elastic fibre network among the extrafusal muscle fibres. In general there are many more elastic fibres around nuclear bag fibres than around nuclear chain fibres and it seems unlikely that the ‘elasticity’ of nuclear chain fibres observed experimentally can be due to the few elastic fibres which surround them. A comparison of the arrangement of elastic fibres on nuclear bag fibres in their extracapsular regions and in the lymph space suggests that nuclear bag fibres are more easily extensible within the lymph space: different portions of the same nuclear bag fibre may therefore also differ mechanically. In human muscle spindles two types of nuclear bag fibre are distinguished: in one type the elastic fibres are concentrated on either side of the equatorial region, whereas in the other type they are more evenly distributed along the length of the fibre. This suggests that these bag fibres may be subjected to different mechanical stresses, possibly due to different motor innervation. Most of the elastic fibres in the region of the primary sensory ending ramify among the inner capsule cells immediately surrounding the intrafusal bundle. This may be a mechanism of bridging the coils of the primary sensory ending while maintaining or increasing the mechanical strength of the region. Each individual intrafusal fibre has a reticulin covering along its length and the sensory nerve terminals lie between the intrafusal fibre and its reticulin covering. In the equatorial region the entire intrafusal bundle is bound together by an additional covering of reticulin. It is suggested that when intrafusal fibres are stretched the sensory endings may be compressed between the intrafusal muscle fibre and the reticulin and/or elastic fibres with resultant distortion and depolarization of the sensory endings.
THE MOVEMENT OF AN UNEMULSIFIED OIL TEST MEAL AND AQUEOUS‐AND OIL‐PHASE MARKERS THROUGH THE INTESTINE OF NORMAL AND BILE‐DIVERTED RATS
Authors: Brand S. J. , Morgan R. G.H.
Published: December 2014

An unemulsified oil test meal containing aqueous‐ and oil‐phase markers (PEG and 3H labelled triether) was fed to control and bile fistula rats. PEG moved ahead of the lipid phase in all groups, and was of limited value as a marker for the test meal. Triether was an excellent marker for studies of gastric emptying. An unexpectedly high correlation was seen between the triether and the test meal and its digestion products in the intestine. The results suggest that triether is a valid marker for following the movement of lipid through the bowel under the conditions of this study. Triether/fat ratios indicated that fat absorption occurred largely from the upper small bowel in control animals and from the lower small bowel in the absence of bile.

Bile diversion resulted in more rapid gastric emptying initially, but very slow gastric emptying of the last part of the oil test meal. Intestinal transit of test meal or either marker was not significantly affected by bile diversion. No evidence for a direct effect of bile diversion on gastrointestinal motility was found.
THE INCIDENCE AND PROPERTIES OF β AXONS TO MUSCLE SPINDLES IN THE CAT HIND LIMB
Authors: McWilliam P. N.
Published: December 2014

The distribution of β axons to muscle spindles in the tenuissimus and abductor digiti quinti medius (A.D.Q.M.) muscles of the hind limb of the cat was determined by testing the action of single motor axons, capable of producing extrafusal contraction, isolated in the ventral spinal roots on the discharges of individual muscle spindle primary sensory endings recorded in the dorsal spinal roots. The proportion of spindles with β innervation was 41% in A.D.Q.M. and 30% in tenuissimus. The proportion of fast motor axons that were β axons was 28% in the A.D.Q.M. and 11% in tenuissimus; usually each , β axon innervated a single spindle while no spindle received more than two β axons. The β axons were dynamic in nature and those to any one muscle tended to have slightly lower conduction velocities than the α axons though some overlap did occur.

The extent to which β axons can account for the fact that in isolated spindles axons selective to either nuclear bag or nuclear chain fibres are found in about equal proportions whereas a ratio of three static to one dynamic γ axons is found electrophysiologically is discussed. An explanation for the low incidence of β innervation previously found electrophysiologically and the considerably higher incidence found histologically is given.
THE TERMINAL HEPATIC MICROCIRCULATION IN THE RAT
Authors: Koo Anthony , Liang Isabella Y. S. , Cheng K. K.
Published: December 2014

The hepatic microcirculation was observed microscopically in the transilluminated liver of the rat. The portal and hepatic venous microvessels were classified into four orders according to their branching hierarchy, and the hepatic sinusoids into branching, direct and interconnecting types according to their topographic arrangements. The diameters of the various orders of microvessels and types of sinusoids were measured by serial photomicrography, and the velocity of the erythrocytes in these various microvessels and sinusoids by the dual‐slit photometric technique. The microvascular volume flows were calculated from these data. In both portal and hepatic venous systems, the erythrocyte velocity and the volume flow significantly decreased in successive orders of the microvessels in apparent relation to the cross‐sectional areas. The diameters of the three types of sinusoids did not significantly differ, but the velocity of the erythrocytes in the direct sinusoid was significantly faster than that in the branching sinusoid while that in the inter‐connecting sinusoid fluctuated widely.
THE EFFECTS OF VAGOTOMY ON VENTILATION AND BLOOD GAS COMPOSITION IN DOG, SHEEP AND RABBIT
Authors: Kashani Monir , Haigh A. L.
Published: December 2014

The influence of vagotomy on resting arterial blood gases (PaCO2 and PaO2) and on the ventilatory responses to hypercapnia and hypoxia was studied in three different species of anaesthetized animals. After bilateral cervical vagotomy resting PaCO2 generally declined. In the dog, where this was studied more fully, resting PaCO2 declined significantly (8·13±0·67 mm Hg) over several hours, but PaO2 changes were not significant.

After vagotomy tidal volume (VT), but not frequency (f), increased with increasing chemical drive. It is concluded that the increase in frequency in response to increased CO2 or decreased O2 is dependent on the vagal mechanisms.

Minute volume, fractional inspiratory CO2 (VE, FICO2) and minute volume, fractional inspiratory O2 (VE, F102) relationships have been determined. Although vagotomy may not decrease the response of minute volume of ventilation in the lower part of VE, FICO2 curves (mild hypercapnia), it flattened the upper parts of the curves in sheep and rabbits, and to a lesser extent in dogs; it seemed that there was little species difference in this respect. Ventilatory responses to graded hypoxia were close to or slightly higher than pre‐vagotomy values throughout the VE, FIO2, curves in all animals.
ACTIVITIES OF MIXED FUNCTION OXIDASES, UDP‐GLUCURONYL TRANSFERASE AND SULPHATE CONJUGATION ENZYMES IN GALLIFORMES AND ANSERIFORMES
Authors: Bartlet A. L. , Kirinya L. M.
Published: December 2014

The activities of certain drug metabolizing enzymes have been measured in liver and kidney slice preparations from domesticated birds. Aminopyrine demethylase activity was significantly lower in liver slices from the duck (Aylesbury x Pekin, Khaki‐Campbell) than from the rat (Wistar), and in the Aylesbury x Pekin duck lower than in the turkey (Triple 6 FLX), chicken (Brown Leghorn, Rhode Island Red x Light Sussex) and goose (Emden x Doulouse). The microsomal cytochrome P—450 was lower in duck liver (Aylesbury x Pekin) than in rat liver, and the aniline hydroxylase and aminopyrine demethylase activities in a 10,000 g supernatant fraction of liver were lower in duck preparations (Aylesbury x Pekin, Khaki‐Campbell) than rat preparations. These observations suggest that the duck is likely to be susceptible to drugs which are metabolized by the cytochrome P‐450 containing mono‐oxygenases.

UDP‐Glucuronyl transferase activity was not detectable in liver and kidney slices from two mature geese. This observation was not the outcome of a deficiency of UDP‐glucuronic acid, rapid breakdown of glucuronide by β‐glucuronidase or the presence of a substance inhibitory to UDP‐glucuronyl transferase. Liver slices from geese, ducks (Aylesbury x Pekin) and chickens contained low UDP‐glucuronyl transferase and high sulphate conjugation enzyme activities, whereas the reverse was found in Khaki‐Campbell ducks. The activities of UDP‐glucuronyl transferase and the sulphate conjugation enzymes were both relatively high in liver slices from the turkey and rat.

The kidney contained lower enzyme activities than the liver except in the duck (Aylesbury x Pekin), in which low activities of aminopyrine demethylase and UDP‐glucuronyl transferase were present in slices of both organs.

In liver slices from chickens and geese the activities of aminopyrine demethylase and the sulphate conjugation enzymes were similar in mature and immature birds, and the activity of UDP‐glucuronyl transferase was considerably higher in chicks and goslings than in mature birds of the same species.

In the chick the activities of aminopyrine demethylase, UDP‐glucuronyl transferase and the sulphate conjugation enzymes were higher in the duodenum than the remainder of the alimentary tract. The activities of these enzymes in pieces of duodenum were as high as those in slices of liver.

The inclusion of sulphate in the incubation medium produced a significant increase in the synthesis of p‐nitrophenyl sulphate in liver slices and not kidney slices except those from the duck. The kidney slices seemed to produce sufficient sulphate for the reaction of the sulphate conjugation enzymes to proceed at the maximum rate, but the liver slices did not do so.
THE EFFECT OF VASOPRESSIN UPON THE EXCRETION OF CALCIUM BY THE SHEEP
Authors: Beal A. M. , Clark R. C. , Cross R. B. , French T. J.
Published: December 2014

Vasopressin (140 µU/min) was infused intravenously into 12 conscious merino ewes for 2 hr. Urine flow rate and free water clearance were consistently reduced. There was no effect upon renal plasma flow, glomerular filtration rate or the rate of excretion of sodium, potassium, magnesium, chloride or phosphate. Although all animals received 75 mmol calcium chloride into the rumen on the previous day, five commenced the experiment with calcium excretion rates of less than 1 µmol/min. In these, vasopressin further decreased calcium excretion. In seven animals with calcium excretion rates between 2 and 20 µmol/min vasopressin had no effect upon either total calcium or free ionized calcium excretion rate.
RESPIRATORY RESPONSES TO CO2‐REBREATHING IN NIGERIAN MEN
Authors: Patrick J. M.
Published: December 2014

In 36 young Nigerian men, ventilatory capacity and the changes in ventilation, tidal volume and tidal Pco2 during oxic CO2‐rebreathing have been measured. CO2 response lines and breathing rhythms have been determined and analysed in relation to the anthropometric and lung function data. Previous findings that Nigerian men have a substantially lower ventilatory capacity than Europeans at a standard height and age are confirmed. Breathing rhythms in Nigerians appear to be the same as in other ethnic groups studied. CO2‐sensitivity varies with FVC, as found previously in Europeans and New Guineans. However, at a standard FVC of 4 l, Nigerian men have the same CO2‐ sensitivity as Europeans, and not a lower value like New Guineans.
THE DISTRIBUTION AND CLEARANCES OF HORMONES AND METABOLITES IN THE CIRCULATION OF THE FOETAL SHEEP
Authors: Jones Colin T. , Rurak Dan
Published: December 2014

Plasma hormone and metabolite concentrations have been measured in the plasma of blood collected simultaneously from the femoral artery, umbilical vein and carotid artery of the exteriorized foetal sheep. The concentration of vasopressin and catecholamines was consistently lower and of glucose, lactate and corticosteroids consistently higher in the umbilical vein compared with the femoral artery. ACTH concentrations showed no consistent pattern and fluctuated widely at each site, but during synacthen infusion the concentration in the umbilical vein was consistently lower than in the femoral artery. For corticosteroids the concentration in the carotid artery was much lower than that in the umbilical vein; the converse was true for catecholamines. Concentrations in the carotid and femoral artery were similar for all compounds investigated. These results indicate that the placenta is a major site of vasopressin, catecholamine and ACTH clearance and of glucose, lactate and corticosteroid production. The foetal liver is probably a major site of corticosteroid and catecholamine clearance.
VARIATIONS IN PERMEABILITY ALONG INDIVIDUALLY PERFUSED CAPILLARIES OF THE FROG MESENTERY
Authors: Michel C. C. , Levick J. R.
Published: December 2014

When single capillaries in the exposed transilluminated frog mesentery were perfused with solutions containing patent blue V (molecular radius 0·7 nm), unbound T1824 (molecular radius 1·3 nm) and T1824‐albumin (molecular radius 3·6 nm), the coloured molecules initially appeared to enter the extracapillary tissues more easily at some places than at others along the length of the vessels. Three patterns of extravascular distribution were observed: (1) High frequency unevenness: patent blue V and unbound T1824 first appeared outside the capillary as spots, bars or bands set at intervals 30—80 µm apart along the length of the vessel. (2) Low frequency unevenness: at later times, the extravascular dye was seen to be unevenly distributed on a much larger scale, with lengths of vessel of up to 400 µm surrounded by little extravascular dye separating similar lengths around which much dye had accummulated. This pattern of distribution was seen for all three solutes. (3) Arteriovenous gradient: perfusions with all three solutes resulted in more extracapillary colouration accumulating around the venous ends of the capillaries. Reasons are given for believing that the distribution of extracapillary solute reflected the distribution of permeability along the length of the capillary. The variations in permeability were attributed to an uneven distribution of small pores along the capillary rather than to presences of large pores.
THE EFFECTS OF BRADYKININ ON AFFERENT UNITS IN INTRAABDOMINAL SYMPATHETIC NERVE TRUNKS
Authors: Floyd K. , Hick Verity E. , Koley Juthika , Morrison J. F. B.
Published: December 2014

The effects of intra‐arterial injections of bradykinin on afferent discharges in the splanchnic and hypogastric nerves have been studied. All units which were excited by the peptide were mechano‐sensitive. Following i.a. bradykinin, the slowly adapting mechanoreceptors associated with the bladder showed increased discharge rates which appear to be related to changes in intravesical pressure. When the effects of bradykinin on the bladder were blocked by cord cooling, the afferents were not excited. It is concluded that bradykinin causes discharges in the slowly adapting mechano‐receptors around the bladder because it causes bladder contractions, and not because of any chemosensitivity of the nerve ending.
ON THE EXISTENCE OF PARASYMPATHETIC MOTOR NERVES TO THE SUBMAXILLARY GLAND OF THE DOG
Authors: Emmelin N. , Gjörstrup P. , Thesleff P.
Published: December 2014

Duct pressure and salivary flow were recorded in submaxillary glands of anaesthetized dogs, to study whether parasympathetic stimulation caused effects referable to activity in myoepithelial cells. At fairly low frequency of stimulation, e.g. 3 Hz, the pressure curve had two distinct components, with an initial steep and a secondary gradual rise. It resembled that obtained on sympathetic stimulation, where the first phase is ascribed to myoepithelial contraction, the second phase to secretion. When parasympathetic stimulation ceased, there was first a steep fall, then a more gradual decline of the pressure. The steep fall was of the same magnitude as the steep rise; both increased with the frequency of stimulation. The size of the initial fall was fairly independent of the pressure level from which it started. Such a steep fall did not occur subsequent to parasympathetic stimulation if the myoepithelial cells were already in a state of strong contraction caused by sympathetic impulses or bradykinin. The phase of steep fall was inferred to be due mainly to relaxation of contracted myoepithelial cells, the following decline to back‐flow of fluid into the gland.

The salivary flow rate was highest at the beginning of a period of parasympathetic stimulation, particularly if the duct system was well filled and the saliva thin. It was concluded that myoepithelial contraction had initially expelled saliva. A brief period of parasympathetic stimulation while a slow basal secretion at constant rate was going on was found to accelerate this flow, and afterwards there was a transient deceleration of the flow. Acceleration was attributed partly to myoepithelial contraction, mainly to superimposed secretion; retardation to myoepithelial relaxation. The effect appeared independently of the way in which the basal flow was evoked, and the retardation resembled that seen after sympathetic stimulation or bradykinin.
TEMPORAL EFFECTS IN THE ESTIMATION OF PULMONARY DIFFUSING CAPACITY
Authors: Kindig Neal B. , Hazlett David R.
Published: December 2014

Steady state estimates of the pulmonary diffusing capacity for carbon monoxide (DLco) require measurement of the uptake and the average alveolar partial pressure of carbon monoxide (PACO). The expired alveolar sample obtained by different experimental methods and/ or breathing patterns rarely represents the actual PACO. It is widely accepted that nonuniform distribution of ventilation, diffusion and perfusion causes discrepancies in the measurement of diffusing capacity. An additional source of error in choosing PACO arises in the sampling time chosen by the experimental method. A theoretical study of a ramp‐with‐pause and a square breathing pattern demonstrates that the sample‐time error exists even in the homogeneous lung. The study shows for the homogeneous lung that the correct fractional concentration of alveolar carbon monoxide ( FAV) occurs at a time ( TAV), one‐half of a breathing period after the effective inspiration time ( TI) for the two very different breathing patterns. T, is well‐defined in relation to any breathing pattern which can be approximated by ramps and pauses. If TAV and the sample time chosen by the experimental method are known, then the measured DLCO can be corrected to the actual diffusing capacity (DL). The theory agrees with experimental results and computer simulations of inhomogeneous lungs from the literature. This agreement suggests that the theory for the homogeneous lung is also relevant to the inhomogeneous lung.
INFLUENCE OF RUMINAL AND PLASMA OSMOTIC PRESSURE ON SALIVARY SECRETION IN SHEEP
Authors: Warner A. C. I. , Stacy B. D.
Published: December 2014

The osmotic pressure of the rumen contents and also of the blood was altered by intraruminal administration of water or hypertonic solutions. It was found that alterations in osmotic pressure were accompanied by inverse changes in the flow rate of mixed saliva. Intravenous infusion of hypertonic solutions, causing elevation of the osmotic pressure of the blood without affecting that of the rumen, also caused a reduction of salivary secretion rate. The flow rates of both parotid and residual saliva were affected.

When strongly hypertonic solutions of sodium or potassium salts were infused into the rumen, or sodium salts or urea were infused into the blood, the concentration of those substances increased in the saliva. Other treatments had little effect on salivary composition.
A STUDY OF CHEMICALLY INDUCED ACUTE INFLAMMATION IN THE SKIN OF THE RAT
Authors: Kiernan J. A.
Published: December 2014

Oedema due to application of benzene to the skin was reduced following prior sensory denervation and in animals systemically pre‐treated with capsaicine (which is known to confer resistance to chemical irritants) or compound 48/80 (which depletes the body of mast cells). Increased degranulation of mast cells in the benzene‐treated skin was unaffected by denervation but did not occur after treatment with capsaicine.

Antidromic stimulation of a cutaneous nerve caused oedema and degranulation of mast cells, both of which were less severe than the corresponding effects of topically applied benzene. These effects were completely prevented by prior treatment with capsaicine and the oedema was less severe in 48/80‐treated rats. Hence, the presence of mast cells was necessary for full development of the effects of antidromic stimulation.

These observations indicate that axon reflexes in sensory fibres contribute to, but are not entirely responsible for, the development of oedema in chemically irritated skin. The prophylactic action of capsaicine may be due to the prevention of degranulation of mast cells rather than to a direct effect on cutaneous nerve endings. These conclusions are embodied in an hupothesis purporting to explain the involvement of axon reflexes, mast cells and various humoral mediators in chemically induced acute inflammation.
ADRENERGIC MECHANISMS IN THE HEPATIC MICROCIRCULATION IN THE RAT
Authors: Koo Anthony , Liang Isabella Y. S. , Cheng K. K.
Published: December 2014

The in vivo hepatic microvascular bed of the rat was observed microscopically in the transilluminated liver and the diameter of the hepatic sinusoids was measured by serial photomicrography. Intraportal infusion of tyramine induced concentration‐dependent constriction of the hepatic sinusoids, but also dilatation of the sinusoids when the dose was small. These effects were attributed to the release of endogenous noradrenaline which activated either alpha‐ or beta‐adrenergic receptors and caused constriction, or dilatation, of the sinusoids respectively. Adrenaline and noradrenaline induced similar changes in the hepatic sinusoids as tyramine, while phenoxybenzamine induced dilatation, and propranolol constriction, of the sinusoids. All the above responses were abolished by pretreatment with reserpine. A possible noradrenaline‐mediated basal vasomotor tone in the hepatic sinusoids for autonomic control of the blood flow in the sinusoids was postulated.
INFLUENCE OF LEVEL OF HABITUAL ACTIVITY ON PHYSICAL WORKING CAPACITY AND BODY COMPOSITION OF POST‐PUBERAL SCHOOL BOYS
Authors: Watson A. W. S. , O'Donovan D. J.
Published: December 2014

The relationships between level of habitual activity, physical working capacity at a heart rate of 170 beats per minute (PWC170), % fat and body size, have been investigated in 85 post‐puberal males aged 16 to 18. Percentage of fat was estimated from the sum of four skinfold thicknesses and body size characterized by: height and weight; arm, chest, calf and thigh circumferences; biacromial and bi‐iliac diameters. PWC170 was found to be significantly related to level of habitual activity and to most measures of body size; multiple regression analysis indicates that level of habitual activity and size respectively account for 34% and 37% of the variance in PWC170. When differences in the body weight of the subjects were statistically removed, % fat was related positively to arm circumference, and negatively to height and bi‐iliac diameter. There was no relationship between % fat and level of habitual activity. The possible significance of these results is discussed.