bluuebunny/crossref_metadata_2025_split huggingface dataset:
The intestinal absorption of pig and bovine immune lactoglobulin and human serum albumin by the new‐born pig
Authors: Pierce A. E. , Smith M. W. 
Published: December 2014

1. Homologous and heterologous colostral immune globulins and human serum albumin were fed to new‐born pigs and an attempt was made to estimate the amounts appearing subsequently in serum.2. All three proteins, fed separately in large amounts to different pigs, appeared in the serum in low concentration about 45 min after feeding, and then rose quickly to a high level. No difference could be detected between the amounts absorbed when equal amounts had been fed but there was a wide variation between pigs. Previous dialysis of pig colostrum against bicarbonate saline did not affect the rate or amount of pig immune globulin absorbed after feeding.3. When pig and bovine colostral IgG were fed together at equal concentrations in bovine colostrum, the absorption of pig IgG was greater than that of bovine IgG. Human serum albumin, added to bovine colostral IgG in bovine colostrum, was absorbed readily and this did not interfere significantly with the absorption of bovine colostral IgG.4. The efficiency with which the pig intestine absorbed bovine colostral IgG depended on the dose and/or concentration fed, increasing as the dose fed was increased to 2 g and remaining constant for higher doses.5. Some of the absorbed immune globulin was shown to exist in a partly degraded form.6. The process of protein transfer across the intestine of the new‐born pig may select, to a limited degree, between different proteins, but the digestion of protein shown to take place and the large variation between individual pigs makes interpretation of these results uncertain.
The in vitro transfer of bovine immune lactoglobulin across the intestine of new‐born pigs
Authors: Pierce A. E. , Smith M. W. 
Published: December 2014

1. Everted sacs of pig intestine, used soon after birth, maintained transmural potentials and transferred water and glucose to the serosal surface.2. Immune globulin, fed as bovine colostrum to the new‐born pig, appeared in the serosal fluid of everted sacs during incubation in bicarbonate saline. The particular segment showing maximum transferring ability varied between limits and appeared to depend on the amount or concentration of colostrum fed to the pig. Sacs from unfed pigs incubated in bovine colostrum also transferred colostral IgG to the serosal fluid. This transfer was dependent on the concentration of colostral IgG in the incubation medium and became more pronounced in the middle third of the small intestine.3. Human serum albumin inhibited the transfer of colostral IgG and about twenty molecules of albumin were transferred for every molecule of colostral IgG, when both were presented together in equal concentration on the basis of weight, to the middle segment of the small intestine.4. Some of the immune globulin collected in vitro after feeding bovine colostrum was found in a degraded form, but the amounts present could not be estimated. There was no apparent degradation of immune globulin in the purely in vitro experiments.5. The in vitro transfer of bovine colostral IgG showed selectivity between molecules of albumin and colostral IgG, the nature of which warrants further study.
The distribution of [14C]sucrose within the skeletal muscle of the rat in vitro
Authors: Law R. O. 
Published: December 2014

1. The distribution of [14C]sucrose within the plantaris muscle of the rat has been examined by suspending muscles in oxygenated Ringer containing this marker and subsequent analysis of the muscle.2. Histological examination of sections of muscle treated in this way indicates considerable distortion of muscle fibre pattern; this has been held to cast doubt upon the validity of such a method as a means of extracellular space examination.3. The rate of K+ loss from muscles under these conditions has been examined by flame photometry. Up to 50% of the original muscle K+ has been shown to be lost by efflux within approximately 1 hr from the commencement of soaking.4. It is considered that these findings indicate severe deterioration in the physiological condition of the muscle, and it is suggested that tissue hypoxia is chiefly responsible for this.
Studies on the mechanism of kinin formation in inflammation
Authors: Zachariae H. , Malmquist J. , Oates J. A. , Pettinger W. 
Published: December 2014

1. Injection of autologous plasma into the subcutaneous space leads to kinin formation in man. Kinin formation was also observed after similar injections of homologous plasma in the rat, dog and guinea‐pig. The material withdrawn from the subcutaneous tissue following the injection of plasma was characterized as kinin by inhibition of its formation with trasylol, by inactivation with chymotrypsin and by its pharmacologic effects.2. Kinins were also demonstrated in subcutaneous tissue following injections of compound 48/80, a histamine liberator.3. A slightly acid pH greatly favours the accumulation of kinins in subcutis.4. Human plasma kallikrein was not activated in vitro by histamine, serotonin, nicotonic acid or endotoxin. Human polymorphonuclear leukocytes initiated the formation of kinins in plasma.5. It is suggested that in inflammation, ‘primary mediators’ such as histamine, do not activate plasma kallikrein directly, but rather increase vascular permeability, permitting plasma to enter the extravascular space where conditions for activation exist. Kinin accumulation is enhanced in inflammation where pH is slightly lowered.
Release of neurophypophysial hormones in vitro
Authors: Daniel A. R. , Lederis K. 
Published: December 2014

1. The rate of release of neurohypophysial hormones in vitro, using isolated, halved neural lobes of the rat in an incubation medium containing excess K+ and Ca2+, was measured. The highest average rate of release was observed between 10 and 20 min after commencement of incubation.2. Incubation of isolated, halved rat neural lobes in the presence of acetylcholine, with or without eserine, did not stimulate hormone release. When complete isolated hypothalamo‐neurohypophysial systems were incubated in a suspension medium containing 10−7 mg/ml. acetylcholine a significant increase in the release of oxytocin occurred (P < 0·01); the increase in vasopressin release was less pronounced (P < 0·05).3. Uptake of O2 by the isolated, halved neural lobes and the hypothalamo‐neurohypophysial systems continued for 2‐3 hr, i.e. in excess of the experimental incubation time.4. During the first 40 min of incubation the control halved neural lobes increased in weight; the neural lobes incubated in buffer containing high potassium and calcium showed no increase in weight.5. Neural lobes incubated in buffer containing excess K+ and Ca2+ contained about 3 times as much potassium as controls. The sodium content was not affected significantly.6. Factors involved in the process of neurohypophysial hormone release are discussed.
The effect of infusions of glucose, acetate and amino acids in hourly milk yield in fed, fasted and insulin‐treated goats
Authors: Linzell J. L. 
Published: December 2014

1. Experiments have been carried out in lactating goats milked hourly to assess the value of this technique in studies of milk secretion.2. On refeeding 24 hr‐fasted goats there was an increase in arterial concentration and mammary uptake of volatile fatty acids within an hour, but little increase in hourly milk and lactose yield until the mammary uptake of glucose had also increased (after 2‐3 hr).3. Intravascular infusions of acetate had no effect on milk secretion in 24 hr‐fasted goats but glucose infusions increased milk yield by 62 ± 5% and lactose yield by 87 ± 12% within 3 hr, with no effect on fat secretion. The addition of acetate or acetate plus amino acids had no more effect than glucose alone.4. The yield of milk and lactose could be reduced within an hour by insulin (2 u./kg
I.V.) and this was prevented or reversed by injecting glucose. In one goat, where in spite of a fall in blood sugar, mammary arteriovenous difference and blood flow did not fall, there was little or no fall in milk yield.5. In fasted or insulin treated goats an increase in milk and lactose secretion could be obtained within an hour by infusing glucose into the artery of one gland autotransplanted to the neck, which responded before the control gland in situ, thus showing that the effect of glucose is directly on the mammary tissue.6. In two normally fed goats with a low blood sugar, glucose infusions increased the milk or lactose yield by 30% within 3 hr.7. It is concluded that frequent milking, using minimal doses of oxytocin, is a valid method of studying factors controlling milk secretion and that, in the lactating goat, the availability of glucose to the mammary gland can be a limiting factor for maximum milk secretion.
The relation between spontaneous activity, metabolic rate and the 24 hour cycle in mice at different environmental temperatures
Authors: Mount L. E. , Willmott Jane V. 
Published: December 2014

1. Oxygen consumption rates and levels of spontaneous activity were recorded simultaneously for mice, both singly and in groups, over 24 hr periods at temperatures ranging from 8 to 37° C.2. There was marked 24 hr variation in both metabolic rate and activity, with maxima during the night; the amplitude of the variation diminished at the lower environmental temperatures.3. At 28‐33° C environmental temperatures, increased activity was associated with an increased oxygen consumption rate.4. At 8 and 15° C, increased activity was accompanied by only a small increase in oxygen consumption.5. These results show that thermogenesis from spontaneous activity can take the place of thermoregulatory heat production in the cold.
Penetration of sugars across the blood—brain barrier
Authors: Eidelberg E. , Fishman J. , Hams M. L. 
Published: December 2014

1. A cerebral perfusion method was used to measure the net uptake of arabinose from the circulatory system in cats.2. There was found to be discrimination between the optical isomers of this substance, with apparently greater uptake of the (—)‐form.3. The uptake process was highly temperature dependent, with a Q10 of 3·0.4. The uptake of arabinose was partially inhibited by 1 m
M ouabain perfused concurrently. It was not significantly inhibited by dinitrophenol or phlorrhizin.5. Glucose inhibited competitively the uptake of (—)‐arabinose.6. We conclude that the mechanism involved is of the carrier‐mediated or of the active transport type, and that at least part of it is shared with glucose and probably other sugars.
The relation of blood volume to body weight and arterial haemoglobin levels in rabbits
Authors: Mott Joan C. 
Published: December 2014

1. Relative blood volume (ml./kg) of rabbits calculated from total circulating haemoglobin and blood haemoglobin concentration decreases rapidly during the first few weeks of life and more slowly thereafter.2. In anaemic rabbits over 1 kg body weight, relative blood volume is significantly increased.3. Rabbits under 1 kg body weight have larger blood volumes than would be expected from their anaemia alone, were the relationship deduced in rabbits over 1 kg in body weight applicable. Blood volume was not related to haemoglobin concentration in these immature rabbits.
Further studies of the metabolism of thyroxine and 3,5,3′‐triiodothyronine in the guinea‐pig
Authors: Brown-Grant K. 
Published: December 2014

1. Thyroxine labelled with 125I and triiodothyronine labelled with 131I have been administered simultaneously to guinea‐pigs and their metabolism studied by whole body counting and measurement of radioactivity in urine, faeces, and blood.2. The half‐life of triiodothyronine in the body is about 19 hr, significantly less than that of thyroxine (41 hr).3. After triiodothyronine administration, an unidentified iodinated compound appears in the blood which complicates the estimation of the half‐life of this hormone by measurement of the radioactivity in peripheral blood.4. A previous report, based on measurements of blood radioactivity, that the half‐lives of the two hormones are similar in the guinea‐pig was not confirmed.
Impulse frequency in secretory nerves of salivary glands
Authors: Emmelin N. , Holmberg J. 
Published: December 2014

1. In dogs under pentothal anaesthesia the submaxillary duct was exposed in the neck and a polythene tube tied into it. During the following days the dogs were examined repeatedly, standing in a frame. The highest rates of submaxillary secretion evoked by introducing various foodstuffs or rejectable substances into the mouth were estimated. Finally, the dogs were anaesthetized and the rates of salivary flow recorded during electrical stimulation of the chordalingual nerve at different frequencies.2. The frequency—response curve for electrical stimulation has a steep slope up to a frequency of 10/sec, where a salivary flow at a rate of about 90% of the maximal is evoked.3. The fastest secretion that is obtained reflexly on feeding corresponds to a flow which in different experiments varies between 4 and 8 shocks/sec. The very rapid secretion caused by rejectable substances can be reproduced by stimulating at 10‐30/sec.4. In similar experiments on the parotid gland foodstuffs were often, and rejectable substances always found to cause a salivary flow at a rate which exceeded that obtained on maximal stimulation of the auriculotemporal nerve. This supports the view expressed by previous investigators that additional secretory fibres reach the parotid gland of the dog by anatomically unknown routes.
Confirmation from choline acetylase analyses of a massive cholinergic innervation to the rat hippocampus
Authors: Lewis P. R. , Shute C. C. D. , Silver Ann 
Published: December 2014

1. Unilateral lesions were made in the fimbria of adult rats with a stereotaxically‐applied, radio‐frequency current. After 3‐23 days survival, fresh, unfixed, transverse sections were cut of the forebrain. Half the sections were stained histochemically to show the distribution of acetylcholinesterase (AChE) activity. From the other sections, small, anatomically defined areas were dissected out and assayed for choline acetylase (ChAc) activity (acetyl‐CoA: choline‐O‐acetyltransferase EC2.3.1.6).2. In the fimbria, anterior to the lesion, ChAc activity rises sharply and is still approximately twice the normal after 7 days. In the hippocampus, ChAc activity falls: in most experiments activity on the operated side was 20‐40% of that on the control side, but in some experiments values below 10% were obtained. These changes closely parallel those observed in the staining for AChE.3. The results go far towards proving that the hippocampus receives a massive cholinergic innervation via the fimbria. The fibres concerned appear to be those which stain characteristically for AChE and it seems likely that other pathways showing the same histochemical behaviour are also cholinergic.
Electrophysiological study of the intestinal smooth muscle of the guinea‐pig
Authors: Kuriyama H. , Osa T. , Toida N. 
Published: December 2014

The membrane properties of single cells of intestinal smooth muscle of duodenum, jejunum, ileum, caecum and rectum of guinea‐pig have been studied.1. The membrane potentials of longitudinal muscles of the duodenum, jejunum, ileum, caecum and rectum varied from 54 to 56 mV and those of circular muscles of jejunum, ileum, caecum and rectum varied from 57 to 60 mV. The ablated longitudinal muscle had a slightly lower value (50 mV) than the intact one.2. The longitudinal muscle generated spontaneous discharges but these were rare in the circular muscles of the intestine except for the caecum. Overshoot potentials could be observed in all regions of the intestine. The maximum rate of rise of the spontaneously discharging longitudinal muscles varied from 11 to 18 V/sec.3. Not all of the slow potential changes (but at least some) were generated by the nervous elements distributed between the muscle layers and in them.4. The conduction velocities measured from the longitudinal muscles of jejunum and rectum in the presence of tetrodotoxin were 2·1 cm/sec and 4·0 cm/sec respectively.5. Chronaxies of the longitudinal muscles of jejunum and rectum were 2‐5 msec and 5‐18 msec respectively.6. Intracellular stimulation of the single cells of the duodenum and caecum could trigger a spike, similar to that observed in the taenia coli. The spikes were mostly graded ones; a spike of full size was rarely elicited. When the spikes were triggered, the after‐hyperpolarization appeared consistently presumably caused by the increased potassium conductance.7. The effective membrane resistance and the time constant were measured for the longitudinal muscles of the jejunum and rectum. When spikes were generated by intracellular stimulation the observed values were 40‐50 MΩ and 3‐5 msec in both tissues. These values were the same as those observed in the taenia coli.8. When the time constant of the membrane was measured by the extracellular polarizing method, the longitudinal muscles of the jejunum especially and the rectum had smaller time constants than the taenia coli.9. The differences of conduction velocity and chronaxie of the different regions of the intestine are discussed in relation to the cable properties of the tissues which are directly influenced by the morphological arrangements of the tissues.
The partition of sodium fluxes in isolated toad oocytes
Authors: Dick D. A. T. , Lea E. J. A. 
Published: December 2014

1. The rate constant for Na efflux from the oocyte calculated from (d/dt) (ln [Na*]i]) is only approximately 52% of that calculated from (d/dt)[(ln(d[Na*]i)dt)]. The difference may be interpreted by supposing that 48% of the internal Na of the oocyte is either bound to proteins or sequestered in cell organelles.2. The mean rate constant for Na efflux was 6·4 × 10−3 min−1 corresponding to an apparent Na efflux rate of 13·3 p‐mole/cm2.sec. When this is corrected for the increase in surface area produced by microvilli the true efflux rate is 1·1‐1·3 p‐mole/cm2.sec.3. The action of ouabain (1‐5 μ
M) appears to involve two different effects: (a) there is 48‐65% inhibition of the membrane Na pump, and (b) there is a release of some of the sequestered Na in the cell.4. Removal of external K causes a 40% reduction in Na efflux although this value may be an underestimation owing to the presence of K which has leaked from the cell and may be retained near the cell surface.5. Raising the external K concentration to 15 m
M reduces the inhibitory effect of ouabain by approximately a half.6. It was concluded that the Na pump in the toad oocyte may have a slightly lower level of activity than that in frog muscle, but that its general properties are similar to those in frog muscle and some other animal cells.
A search for pulmonary arterial chemoreceptors in the cat, with a comparison of the blood supply of the aortic bodies in the new‐born and adult animal
Authors: Coleridge Hazel , Coleridge J. C. G. , Howe A. 
Published: December 2014

1. Electrophysiological and histological techniques have been employed to search for pulmonary arterial chemoreceptors in kittens and cats.2. In cats, impulses were recorded from vagal fibres arising from chemoreceptors in the aortico‐pulmonary region. The receptors were identified by their response to hypoxia, and their location was investigated by comparing the effects of injecting drugs at various sites in the pulmonary and systemic circulations. In only one of a large number of experiments did a chemoreceptor appear to receive pulmonary rather than systemic arterial blood.3. No chemoreceptor impulses were evoked when a segment of the pulmonary artery was perfused as described by Duke, Green, Heffron & Stubbens (1963).4. The vasculature of the aortico‐pulmonary bodies was displayed by micro‐dissection following injection of coloured gelatin masses, and the bodies were examined histologically. In the new‐born kitten, the pulmonary artery invariably furnished a branch to some aortic bodies but the vessel frequently anastomosed with systemic arteries. As post‐natal development proceeded the vessel became occluded, and in most kittens more than a month old and in forty‐one of forty‐three cats the aortic bodies were supplied wholly by systemic arteries.5. It was concluded that a pulmonary arterial supply to aortic bodies in the adult animal is an uncommon variation owing to the abnormal persistence of a foetal condition.6. Results indicated that the nomenclature introduced by Howe (1956) is, with slight modification, a useful method of classifying the various groups of aortic bodies according to their position, blood supply and innervation.
The effect of heating and cooling the hypothalamus on behavioural thermoregulation in the pig
Authors: Baldwin B. A. , Ingram D. L. 
Published: December 2014

1. Pigs were trained to push a switch with their snouts in order to obtain a short burst of infra‐red heat on the skin.2. When the preoptic region of the hypothalamus was cooled by means of an implanted thermode, the rate at which the heaters were turned on increased at environmental temperatures ranging from 0 to 25° C. At 30 and 35° C cooling sometimes had no effect.3. The preoptic region was warmed either by means of a thermode or using radio‐frequency heating from implanted electrodes. Warming the preoptic region decreased the rate at which the infra‐red heaters were turned on, but the effect was not as obvious as the increases observed during cooling.4. Pigs placed in a cold or neutral environment did not learn to push a switch in order to obtain radio frequency heating of the preoptic region.
The demonstration of luteinizing hormone releasing factor in hypophysial portal blood of pro‐oestrous and hypophysectomized rats
Authors: Fink G. , Nallar R. , Worthington W. C. 
Published: December 2014

1. A method for the routine collection of hypophysial portal blood from rats under direct vision has been described.2. This method has been used to obtain portal blood from adult female rats in pro‐oestrus and adult female rats which had been hypophysectomized at least 14 days before collection.3. The pooled plasma from this blood was assayed for activity, resembling that of luteinizing hormone releasing factor (LRF), by the ovarian ascorbic acid depletion method.4. The portal plasma from both groups of donor animals exhibited significant activity when compared to peripheral plasma controls.5. It is concluded that the ovarian ascorbic acid depleting activity of portal plasma was due to LRF.6. The possibility that some of the activity exhibited by portal plasma from pro‐oestrous rats was due to contamination of the samples by LH containing backflow blood from pituitary sinusoids is discussed.7. The possibility that the ovarian ascorbic acid depleting activity of the hypophysial portal plasma was due to either vasopressin or a nonspecific factor has been excluded.