bluuebunny/crossref_metadata_2025_split huggingface dataset:
CHANGES IN URINARY WATER AND ELECTROLYTE EXCRETION IN SODIUM‐LOADED SHEEP IN RESPONSE TO INTRAVENOUS INFUSION OF ARGININE VASOPRESSIN
Authors: Scott D. , Morton J. J. 
Published: December 2014

Mature sheep receiving supplements of sodium chloride into the rumen were given intravenous infusions of arginine vasopressin at rates varying from 4·6–23 pmol/min (2–10 mU/min). Infusion of the hormone led to an increase in urine flow and to increases in the amounts of sodium and chloride excreted, the effect on flow was, however, the greater so that the osmolality of the urine fell during the infusions.In sheep given intravenous infusions of a hypertonic sodium chloride solution addition of vasopressin to the infusate led to the formation of a larger volume of urine containing a higher proportion of the infused salt load compared to when the salt solution alone was given. As before the effect on flow was the greater and hence the osmolality of the urine was lower when the hormone was given.In other experiments intravenous infusion of a hypertonic sodium chloride solution at rates providing 2—8 mmol NaCl/min led to increases in urine flow and increases in sodium and chloride excretion, the size of these increases being proportional to infusion rate. Plasma vasopressin levels markedly increased during these infusions, the levels seen being similar to those seen in sheep given vasopressin in amounts which increased both urine flow and electrolyte excretion. This suggests that during hypertonic salt loading vasopressin probably contributes directly to the increases in urine flow and the increases in electrolyte excretion which are seen. Further evidence in support of this was obtained in experiments in which a greater natriuretic response was seen in sheep given a hypertonic sodium chloride solution into the carotid artery as opposed to the jugular vein and where it was shown that plasma vasopressin levels were indeed higher when the solution was given into the artery.
RESPONSE OF THE REGIONAL LYMPHATIC SYSTEM OF THE SHEEP TO ACUTE STRESS AND ADRENALINE
Authors: Shannon A. D. , Quin J. W. , Jones M. A. S. 
Published: December 2014

An acute pain stimulus resulted in elevated lymph flow and output of cells from the popliteal lymph node of the sheep in the first 15 min after the stress. Efferent lymph flow increased by an average of 93% above the mean resting flow and cell output rose by an average of 170% during this period, but by 30 min after the stress, values for both lymph flow and cell output had returned to normal. The cell content of the efferent lymph was significantly higher in the first 15 min after the acute stress and it is suggested that there is a sizeable pool of lymphocytes within the resting popliteal node which can be mobilized into the lymph by an acute stress. A single intravenous injection of 1 mg adrenaline increased the efferent lymph flow in all the sheep examined but gave rise to an increased cell output in only 50% of the sheep. This indicated that there may be other factors, possibly hormonal, involved in the movement of the pool of lymphocytes out of the regional lymph node following acute stress.Both acute pain stress and adrenaline resulted in an increased afferent popliteal lymph flow and output of cells from the regional tissues in the first 15 min after administration. The results are suggestive of a small pool of lymphocytes in the regional tissues which may be readily mobilized by either acute stress or adrenaline.Part of the increases in efferent and afferent lymph flow observed following acute stress and adrenaline appeared to be due to an increased lymph formation, presumably as a result of an increased capillary pressure. Nevertheless, it is considered that the greater part of the increased flow of lymph from both regions resulted from an accelerated movement of performed lymph.
THE EFFECTS OF VASOPRESSIN ON RENAL SODIUM EXCRETION IN PIGS GIVEN INTRAVASCULAR HYPERTONIC SALT LOADS
Authors: Scott D. , Morton J. J. 
Published: December 2014

Young pigs of about 25–30 kg liveweight were given intravenous infusions of a hypertonic sodium chloride solution (4·6 mol.l–1) at rates varying from 2–6 mmol. min–1. Such infusions resulted in a marked increase in urine flow and in urinary sodium excretion, the size of these increases being proportional to infusion rate. Circulating vasopressin levels were also markedly increased, the size of these increases being the same as those seen in other pigs given exogenous vasopressin in amounts which were shown to increase urinary sodium excretion. This suggests that vasopressin was probably contributing to the increase in renal sodium excretion seen in those pigs given the intravenous salt loads.Further evidence for this was obtained in experiments in which a greater natriuretic response was found to accompany infusion of a hypertonic salt solution into the carotid artery as opposed to the jugular vein and in which it was shown that circulating vasopressin levels were much higher when the solution was given into the artery. Furthermore, addition of exogenous vasopressin to a hypertonic sodium chloride solution greatly increased the amount of sodium excreted during an infusion compared with when the salt solution alone was given.
THE ABSORPTION OF PHENFORMIN AND ITS EFFECTS ON GLUCOSE AND WATER ABSORPTION IN ISOLATED PERFUSED RAT SMALL INTESTINE
Authors: Gardner M. L. G. , Langslow D. R. 
Published: December 2014

The effects of phenformin on glucose and water absorption from isolated perfused rat small intestine were studied. Luminal phenformin inhibited glucose and water absorption progressively as its concentration was increased from 0·1–1·0 mg.ml‐1. At 0·5 mg phenformin ml‐1, inhibition increased with time of exposure to phenformin up to 15 min and thereafter remained constant. Arterial infusion of phenformin (1·0 mg.ml‐1) produced less inhibition of glucose and water absorption. The site of phenformin's action appeared to be intracellular.Phenformin absorption from a luminal perfusate (0·5 mg.ml−1) was measured. Although it was rapidly absorbed (224 µg.cm intestine−1.h−1) from the lumen, less than 2 µg.cm−1.h−1 appeared at the serosal surface of the intestine. In subsequent phenformin‐free perfusion, only 25% of the absorbed phenformin was recovered in the luminal and serosal effluents.
POST PRANDIAL CHANGES IN PAROTID SALIVARY SECRETION AND PLASMA OSMOLALITY AND THE EFFECTS OF INTRAVENOUS INFUSIONS OF SALINE SOLUTIONS
Authors: Carr D. H. , Titchen D. A. 
Published: December 2014

Parotid salivary secretion, reticular (gastric) contractions and blood osmolality were examined in conscious sheep prepared with re‐entrant parotid duct cannulae and given 1000 g of lucerne chaff daily. Osmolality of blood (portal, carotid and jugular) rose by 2–4 mosmoles. kg‐1 within 5 min of fresh food being given, continued to rise (up to 12–30 mosmoles. kg‐1) over the next 3 h and remained above levels detected before fresh food was given for up to 10 h. The greatest changes were in portal blood which was characteristically hyperosmolal to jugular and carotid blood; a difference which disappeared on fasting for 36 h. Parotid saliva which was 5–20 mosmoles. kg‐1 hyposmolal to jugular blood, increased to up to 6 ml. min—1 within 30 sec of the sheep starting to eat and although they continued to do so for some hours remained at these high levels for only about 30 min.Attempts were made to see whether parotid salivary secretion was affected by changing the osmolality of the blood. Reductions in the rate of parotid salivary secretions and sometimes in the rate of reticular contractions were produced in conscious, anaesthetized and decerebrate preparations by making intravenous infusions of hyperosmolal solutions. The effects were stronger, and the latency shorter, when the infusions were made into the portal vein than when made into the posterior vena cava or a jugular vein. They were reduced by vagotomy and splanchnotomy although not abolished by both.Increases in parotid salivary secretion and frequently, but not invariably, in the rate of reticular contractions followed intravenous infusions of isosmolal and hyposmolal solutions. In 6 experiments (of a total of 12) increases in parotid salivary secretion followed the intravenous injection of arginine vasopressin (0·06 mU.kg‐1), in none was saliva reduced by antidiuretic hormone.The possible involvement of peripheral osmoreceptors in the inhibitory effects, and of receptors sensitive to changes in blood volume in the excitatory effects, is raised in relation to post‐prandial changes which occur in blood composition.
CARDIAC OUTPUT DURING SUBMAXIMAL EXERCISE IN NEW GUINEANS: THE RELATION WITH BODY SIZE AND HABITAT
Authors: Patrick J. M. , Cotes J. E. 
Published: December 2014

Cardiac performance in moderate bicycle exercise has been measured in five groups of New Guineans (N = 161). Men and women in both coastal and highland (2000 m) locations were studied, as well as a group of highland men after migration to the coast. The results have all been standardized to an oxygen consumption of 1 l.min−1.Cardiac output values are similar to those previously quoted for Europeans; a significant positive correlation with body size is found, and resident highlanders appear to have slightly larger cardiac outputs (+4%) and larger stroke volumes (+10%) after adjustment for body size, but this is not because they have larger hearts. The highland migrants at sea‐level share none of the ‘altitude’ characteristics of the highland residents and, after size‐adjustment, correspond with the lowlanders. The cardiac frequencies of the lowland women are higher than the other groups (+15 beats. min−1) after adjustment for differences in body size. Their values are close to those found previously for moderately active Europeans, while all the other New Guinean subjects have lower cardiac frequencies probably because of their greater habitual activity.
THE EFFECT OF INTRAVENOUS HYPERTONIC SALINE INFUSION ON RENAL FUNCTION AND VASOPRESSIN EXCRETION IN SHEEP
Authors: Yesberg Nancy E. , Henderson Myrna , Budtz‐Olsen O. E. 
Published: December 2014

Conscious Merino ewes were given an intravenous hypertonic sodium chloride load of 4 mmol. min−1 for 100 min. This resulted in increases in urine flow, sodium and potassium excretion and plasma sodium concentration and osmolality. Urinary vasopressin output and solute‐free water reabsorption increased and plasma renin activity declined. Renal plasma flow and glomerular filtration rate (GFR) rose, as did the solute clearance. The change in urinary osmolality was related to the initial urine osmolality such that when the initial urine osmolality was high the urine became more dilute, and vice versa. Tubular sodium reabsorption increased but the fractional reabsorption rate fell.It is suggested that the increase in GFR was at least partly due to the increase in AVP and that the electrolyte loss can be accounted for by the increase in GFR without necessarily involving AVP or other hormonal effects at the tubular level.
PORTAL CIRCULATIONS AND THEIR RELATION TO COUNTERCURRENT SYSTEMS
Authors: Henderson J. R. , Daniel P. M. 
Published: December 2014

We have reviewed the distribution of portal circulations throughout the animal body; they are commoner than is generally supposed. Most portal circulations consist of two serial capillary beds connected by one or more larger vessels. We have called these ‘convergent’ portal circulations: examples are hepatic portal, placental, hypophysial, renal, ovarian and testicular circulations, as are parts of the lymphatic circulation. A second type of portal circulation, which is less common, consists of two serial capillary beds that are not connected by larger vessels. These we have called ‘continuous’ portal circulations: adrenal and pancreatic circulations are examples of this type.When a countercurrent concentrating mechanism exists in the body it is always part of the primary or secondary bed of a convergent portal circulation, though some convergent portal circulations are not associated with countercurrent mechanisms.
SERUM ENZYME LEVELS DURING EXPERIMENTAL HYPOTHERMIA IN MAN
Authors: Marcus P. , Edwards R. 
Published: December 2014

Deep surgical and accidental hypothermia cause elevations in serum enzyme levels, probably because of ultrastructural cell damage. Many variables hinder work on this problem in the clinical situation and the mechanism is obscure. Accordingly, enzymes and other physiological parameters were monitored in four subjects cooled four times, under controlled conditions in the labotarory, to a mean auditory canal temperature of 35·0°C. Mild hypovolaemia and acidosis occurred.Serum enzyme levels did not change significantly and it is concluded that elevations due to hypothermia cannot be studied in laboratory experiments on heathly volunteers who can only safely be cooled to 35°C.
Vagus Nerves and the Gastric Tissue Histamine Concentration in Pylorus Ligated Albino Rats
Authors: Ganguly A. K. , Gopinath P. 
Published: December 2014

Gastric tissue histamine concentration was determined, 6 and 16 hours after pylorus ligation in vagus intact and vagotomized albino rats and the results were compared with those of respective control animals, sacrificed, 6 and 16 hours after ether anaesthesia alone. The gastric tissue histamine concentration of rats subjected to none of the experimental situations was also determined and taken into comparison.The results show that the stress of pylorus ligation reduced the gastric tissue histamine concentration, the reduction being more with increased duration of stress. On the other hand, subdiaphragmatic vagotomy preserved the histamine concentration of gastric tissue irrespective of the duration to which the animals were exposed following pylorus ligation. It appears that increase in vagal discharges during stress leads to increased liberation of histamine from the gastric wall, thereby, reducing the gastric tissue histamine concentration; the reduction being proportional to the duration of stress and increase in vagal discharges, whereas, in the absence of vagal impulses following subdiaphragmatic vagotomy, the gastric tissue histamine concentration is preserved in spite of the stress to which the animals were exposed.
A New Technique for Maintaining and Monitoring Conscious, Stress‐free Rabbits in a Steady State: Its Use in the Determination of Glucose Kinetics
Authors: Atkins Gordon L. 
Published: December 2014

1. A new technique is described for maintaining and monitoring conscious rabbits in a steady state. Solutions were infused and blood samples were withdrawn without major surgery and without causing stress. Cannulation, for infusion and blood sampling, was via the ear veins and arteries.2. The validity of the technique is discussed with special reference to: the amount of blood removed from the animal; the use of a plasma substitute solution; the use of heparin; and assessing whether the animal was in a steady‐state with respect to glucose.3. The technique was used to determine glucose kinetics in the fasted rabbit after an injection of [2–3H] glucose with subsequent blood sampling over 2 h. A two compartment model was used to calculate certain physiological values, the two principal ones being the glucose uptake rate (3·30±0·24 (13) mg.kg–1. min–1) and the initial volume of distribution (74·8±7·8 (13) ml.kg–1).4. The accuracy and precision of the results obtained from this study are discussed and shown to be more reliable than other published values.
Efferent Fibres to the Aortic Bodies: A search for Their Cell Bodies in the Brainstem of the Cat and Rabbit
Authors: Kidd C. , McWilliam P. N. 
Published: December 2014

An attempt has been made to determine where in the lower brainstem the cell bodies of nonsympathetic efferent fibres in the aortic nerve of the cat and rabbit are located. Horseradish peroxidase (HRP) was placed on the central end of the right cut aortic nerve of anaesthetized animals and, after an appropriate time, sections of the brainstem encompassing the rostral and caudal limits of the dorsal vagal motor nucleus and nucleus ambiguus were examined microscopically for retrogradely transported HRP. Cell bodies labelled by exogenous HRP were not found in any of the cats or rabbits exposed to HRP although reaction product, due to an endogenous response, was observed. Appropriate control experiments were performed to show that the sensitivity of the technique for demonstrating HRP in our hands was adequate.We conclude that the cell bodies of efferent fibres, of non sympathetic origin, in the aortic nerve are likely to be located outside the central nervous system.
The Arrangement of Endocrine and Exocrine Pancreatic Microcirculation Observed in the Living Rabbit
Authors: Fraser P. A. , Henderson J. R. 
Published: December 2014

1. The microcirculation of the pancreas in the anaesthetized rabbit was examined by in vivo microscopy and micro‐cinephotography.2. The islets of Langerhans were identified by their appearance following the systemic injection of diphenylthiocarbazone.3. Arterial injection of Evans blue demonstrated the arrangement of vessels within the pancreas. Blood leaving the islets passed via capillaries into the capillary meshwork; no islet was ever seen to be drained directly by a vein.4. The significance of this portal arrangement is discussed.
Physical Fitness Training in Patients
Authors: Newell J. P. , Kappagoda C. T. , Linden R. J. 
Published: December 2014

Patients recovering after heart valve surgery are not in an optimum state of ‘cardiorespiratory fitness’. To examine this proposition a controlled trial of physical training was undertaken in patients recovering from the replacement of a single heart valve.Patients were allocated to a test or control group two weeks after operation. Each patient performed a submaximal exercise test at entry, and twelve and twenty‐four weeks after this test. The Canadian Air Force exercise programme was undertaken by the test group, while the control group continued normal activities for the twenty‐four weeks between the first and last exercise test. A regression line of submaximal heart rate on oxygen consumption was calculated from the data of each exercise test in each patient. Alterations in this line were used as an ‘index’ of changes in ‘cardiorespiratory fitness’.The individual results showed a consistent improvement in ‘cardiorespiratory fitness’ over the first 12 weeks in both groups. Only patients in the test group continued to improve between 12 and 24 weeks. Thus the exercise programme modified the recovery of ‘cardiorespiratory fitness’ after operation.A physical fitness rehabilitation programme may help these patients gain maximum benefit from corrective surgery.
EFFECTS OF PREGNANCY ON THE FEBRILE RESPONSE IN SHEEP
Authors: Heap R. B. , Silver Ann , Walters D. E. 
Published: December 2014

Pyrogens were injected into unshorn pregnant and non‐pregnant Soay and Clun Forest sheep and the effects on rectal temperature and thermoregulatory mechanisms monitored. Plasma concentrations of unconjugated oestrogens, progesterone and cortisol were measured in the sheep tested in late pregnancy. The effect of pyrogens was also examined in ovariectomized ewes treated with oestrogen and with oestrogen plus progesterone.In contrast to reports of work on shorn sheep all sheep developed a fever even when close to term but the increase in peripheral vasomotor tone normally induced by pyrogens was attenuated in the pregnant Clun Forest ewes.The hormone‐treated ovariectomized animals developed normal fevers and provided little indication of a possible relation between peripheral levels of ovarian steroids and the degree of fever.The question of whether an endogenous antipyretic substance is present in pregnant sheep is discussed.
ROLE OF ANGIOTENSIN II AND BRANDYKININ IN THE DIURESIS CAUSED BY STIMULATION OF ATRIAL RECEPTORS
Authors: Knapp M. F. , Linden R. J. , Mary D. A. S. G. , Pearson M. J. 
Published: December 2014

M. F. KNAPP, R. J. LINDEN, D. A. S. G. MARY & M. J. PEARSONQuarterly Journal of Experimental Physiology (1980) 65, 335–347.The paper is reprinted in full because neither of its tables appeared in the original version. When quoting this paper as a reference the original citation (as above) should be used.
SOME EFFECTS OF DIET ON THE MITOTIC INDEX AND THE CELL CYCLE OF THE RUMINAL EPITHELIUM OF SHEEP
Authors: Goodlad R. A. 
Published: December 2014

The mitotic index of the ruminal epithelium increased rapidly when the diet of sheep was changed from one based on roughage to a concentrate‐based diet. After several days the mitotic index declined to a new level which was slightly higher than that observed initially. Autoradiography of sections of rumen epithelium was used to construct percent labelled mitoses curves, from which the duration of the phases of the cell cycle was determined. The duration of the cell cycle was about 24 hr but decreased to 17 hr when cell proliferation was stimulated by changing the diet of the sheep from roughage to concentrate. The decrease in cell cycle time was mainly the result of the decreased duration of the phase of DNA synthesis (S phase).Data obtained from measurement of the cell cycle, together with the labelling index, were used to calculate the turnover times of the basal cell layer, and to estimate ‘turnover’ times for the entire epithelium. The mean turnover time for the epithelium was 16·5 days when sheep were fed a roughage‐based diet, 10·9 days when fed a concentrate basal diet and 4·3 days when the sheep were in transition between the roughage and the concentrate diets.
RENAL RESPONSE TO HYPOTONIC SALINE LOAD IN FETAL AND NEW‐BORN PIGS
Authors: Alt J. M. , Colenbrander B. , MacDonald A. A. , Forsling M. L. 
Published: December 2014

Kidney function has been studied in pig fetuses (105–109 d of gestation) and neonates (5–7 d old). Urine was collected by catheterization of the ureter. Inulin clearance, the excretion of electrolytes and the osmolality of urine and plasma were measured. In addition the response of the fetal neurohypophysis and fetal and neonatal kidney to a reduction of plasma osmolality was studied. The results show that the inulin clearance increases rapidly in the perinatal period, at a rate greater than would be expected from the gain in body weight.The re‐absorption of Na and K is well developed. The fractional sodium excretion in fetuses is 2% and is 0·1% in the new‐borns. The urine osmolality is high, probably due to high plasma lysine vasopressin levels persisting throughout the experiment. The infusion of hypotonic saline results in a significant decrease of plasma osmolality but only three out of nineteen animals showed an increase in urine flow. Although lysine vasopressin concentrations fell in some animals the urine stayed hyperosmotic as compared with plasma. The results show that fetuses and neonates may react to volume load but in the conditions of these experiments the regulation of plasma osmolality was inadequate.