bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Arterial Hypoxemia upon Acid‐Base Parameters in Arterial Blood and Cisternal Gerebrospinal Fluid of the Rat
Authors: MacMillan V. , Siesjö B. K. 
Published: December 2008

AbstractThe effects of hypoxemia on the acid‐base parameters of the arterial blood and CSF were studied in anesthetized constant ventilated rats. The results showed that there was a one to one relationship between the increase in the CSF lactate and the decrease in the CSF bicarbonate concentration over a wide range of arterial Po2 values. However, the decrease in the CSF pH at constant ventilation was much less than could be expected from the decrease in bicarbonate. This was due to a concomitant fall in the CSF CO2 tension, partly caused by a fall in the arterial CO2 tension and partly by a decrease in the Po2 difference between CSF and arterial blood.
Impulse Activity of the Isolated Spindle in Potassium‐Free Solution
Authors: Husmark I. , Ottoson D. 
Published: December 2008

AbstractThe effect of removal of potassium on the impulse activity of the frog muscle spindle was studied in isolated preparations. The spontaneous activity of the spindle increased over the first 30–40 min and then decreased and finally ceased. These changes were accompanied by alterations in configuration and time course of the action potential characterized by a decrease in amplitude and a lengthening of the impulse which developed into a heart‐like action potential. The sensitivity of the spindle to stretch decreased gradually with time and no conducted activity could usually be evoked by stretch 60–90 min after removal of potassium. Following return to normal Ringer the spontaneous activity and the response to stretch reappeared rapidly. The observed changes can partly be attributed to the effect of potassium removal on the conducted activity of the afferent axon and partly to the effect on the transducting function of the mechano‐sensitive endings.
The Effect of a Noradrenaline Liberator (4, alpha‐dimethyl‐meta‐tyramine) on Reflex Transmission in Spinal Gats
Authors: Fedina L. , Lundberg A. , Vyklický L. 
Published: December 2008

AbstractIn unanesthetized acute spinal cats an i.v. injection of 4, α‐dimethyl‐meta‐tyramine (H 77/77), which liberates noradrenaline (NA), depresses short‐latency transmission from the flexor reflex afferents (FRA) to motoneurones, ascending pathways and primary afferent terminals. The effect is similar to that produced by DOPA but the late flexor reflex evoked from the FRA after DOPA is not found after H 77/77. The effect by H 77/77 is reversed by the adrenergic α‐blockers phenoxybenzamine and chlorpromazine. H 77/77 has no effect in animals in which the stores of NA have been depleted by pretreatment with reserpine and a blocker of tyrosine hydroxylase. It is suggested that H 77/77 inhibits reflex transmission by transmitter liberation from noradrenergic terminals. H 77/77 also depresses short‐latency transmission from the FRA in chronic spinal cats after degeneration of the descending fibres. As a possible explanation it is suggested that the receptor sensitivity may have changed in the neurones deprived of NA terminals or that neighbouring glia cells may have taken over some of the functions of the NA terminals.
Inhibition of the Uptake of Biogenic Amines into Mast Cells by Tricyclic Psychoactive Drugs
Authors: Frisk‐Holmberg Marianne 
Published: December 2008

AbstractThe inhibitory effect of tricyclic neuroleptic and antidepressant drugs was investigated on the uptake of14C‐labelled 5‐hydroxytryptamine (5‐HT), dopamine (DA), noradrenaline (NA) and histamine (Hi) by isolated rat mast cells. All drugs inhibited the amine uptake but varied quantitatively and qualitatively in their blocking effects. Results showed that 5‐HT and NA uptake were competitively inhibited by both neuroleptics and antidepressants, whereas DA uptake only seemed competitively inhibited by neuroleptics.
Dipsogenic Effects of Intracarotid Infusions of Various Hyperosmolal Solutions
Authors: Olsson Kerstin 
Published: December 2008

AbstractThirst in response to intracarotid and intravenous infusions (1.5 ml/min) of various hypertonic, equi‐osmolal solutions was studied in the goat. Intracarotid infusions of 1 M NaCl and of 2 M fructose induced conspicuous cumulative drinking. The amount of water drunk during intracarotid infusions of 2 M urea and glycerol was only about a third of that consumed during the corresponding infusions of NaCl and fructose. During intracarotid infusions of 2 M galactose and glucose drinking was inconsistent. Of the intravenous infusions only hypertonic NaCl had a consistent dipsogenic effect. However, the amount of water consumed was considerably smaller and the latency time for drinking much longer than during the intracarotid infusions of NaCI. It is concluded that intracarotid infusions of hypertonic solutions act as considerably stronger thirst stimuli than corresponding intravenous infusions, and that the most pronounced dipsogenic effect is obtained by intracarotid infusions of those hypertonic solutions which also most effectively release antidiuretic hormone in the hydrated goat. The possibility is discussed that intracarotid infusions may stimulate the thirst mechanism indirectly via a rise in the Na+ concentration of the cerebrospinal fluid.
Sex Differences in the Catecholamine Output of Children
Authors: Johansson Gunn 
Published: December 2008

AbstractUrinary excretion of catecholamines was studied in 240 normal, healthy children 12 years of age during a passive condition (film exposure) and an active condition (arithmetic test) at school. No sex differences in catecholamine excretion were found during the passive condition, whereas, during the work period, boys excreted significantly more adrenaline and noradrealine than girls. A comparison is made between catecholamine excretion levels of the children and adult subjects examined in other studies.
Increased Renal Excretion of Noradrenaline in Rats after Treatment with Prostaglandin Synthesis Inhibitor Indomethacin
Authors: Junstad Marianne , Wennmalm ÅKe 
Published: December 2008

AbstractThe renal excretion of noradrenaline (NA) during prolonged treatment with the prostaglandin synthesis inhibitor indomethacin (Indomée®) was studied in the rat. The excretion of NA was increased by about 50% during treatment with 0.5–2.0 mglkg b.w. of indomethacin, with a slight dose dependence. The results support the hypothesis, based on studies in isolated perfused organs, that thein uivorelease of NA from adrenergic nerve endings is limited by an endogenous, prostaglandin mediated braking system.
The Influence of Chlorpromazine on the Uptake of Biogenic Amines by Rat Mast Cells in vitro
Authors: Frisk‐Holmberg Marianne , Uvnäs Börje 
Published: December 2008

AbstractRat mast cells were incubated with14C‐5‐hydroxytryptamine (5‐HT),14C‐dopamine (DA),14C‐noradrenaline (NA) or14C‐histamine (Hi). The influence of amine concentrations, temperature and metabolic inhibitors indicate that carrier‐mediated transport mechanisms are involved in the uptake of the amines. Chlorpromazine (CPZ) in concentrations of 0.1–10 μM inhibited the uptake of 5‐HT, DA and NA competitively and reduced the uptake of Hi. Ca++ decreased the effects of CPZ. The results suggest that Ca++ may play an important part in the mechanism of action of CPZ.
Release of Acetylcholine in the Parotid Gland of the Dog during Stimulation of Postganglionic Nerves
Authors: Holmberg Jan 
Published: December 2008

AbstractIt has been found recently that the dog's parotid is supplied with postganglionic secretory fibres which travel not only in the auriculo‐temporal nerve but also outside this nerve in the adventitia of the internal maxillary artery. In the present experiments acetylcholine was found to appear in the perfusate from the gland when the auriculo‐temporal nerve was stimulated. When both this nerve and the fibres on the internal maxillary artery were excited, the yield of acetylcholine was doubled. It is concluded that the auriculo‐temporal nerve and the nerves on the internal maxillary artery contain cholinergic nerves in about equal amounts.
Effects of Malate and Oxaloacetate in Canine Subcutaneous Adipose Tissue
Authors: Fredholm Bertil B. 
Published: December 2008

AbstractThe effect of malate and oxaloacetate infusions was studied in the isolated canine subcutaneous adipose tissue. It was found that oxaloacetate (4–7 mM) reduced the venous lactate/pyruvate ratio, whereas malate (6–12 mM) increased it. During and following sympathetic nerve stimulation approximately equimolar amounts of glycerol and free fatty acids (FFA) were released. When oxaloacetate was infused the amount of FFA released increased, whereas the glycerol release was essentially unchanged. Malate, on the other hand, reduced the FFA release in spite of an essentially unchanged glycerol release. Both anions caused an increased uptake of glucose. The changes in re‐esterification induced were similar to that produced by the lactate/ pyruvate couple. The results are taken as circumstantial support for the concept that the degree of re‐esterification can be altered with the intracellular red‐ox state.
Reactions within Consecutive Vascular Sections of the Small Intestine of the Cat during Prolonged Hypotension
Authors: Haglund Ulf , Lundgren Ove 
Published: December 2008

AbstractA plethysmography technique was utilized to investigate the reactions within consecutive vascular sections of the small intestine of the cat during and after a 2–3 h local arterial hypotension at approximately 55 or 30 mm Hg produced by graded arterial occlusion. The sympathetic nerves to the intestine were cut. The resistance vessels were dilated during hypotension, the dilatation being more pronounced the lower the perfusion pressure. In the early phase of hypotension this autoregulation of intestinal blood flow was probably mainly “myogenic” while it was predominantly “metabolic” in the late part of hypotension. When releasing the arterial occlusion, blood flow returned to control after a 55 mm Hg hypotension, while a marked prolonged vasodilatation was observed after the 30 mm Hg hypotension. The capillary filtration coefficient was not changed from control during a hypotension at 55 mm Hg while it was enhanced at 30 mm Hg. Mean capillary hydrostatic pressure seemed to increase in the latter half of most experiments performed at this level. An additional, transient augmentation of capillary pressure seemed to occur after the hypotension. Upon releasing the arterial clamp after a 30 mm Hg hypotension the whole cardiovascular system seemed to derange progressively to judge by a decline of arterial blood pressure.
Uptake of 3H‐Atropine in the Pancreatic Islets and the Parafollicular Cells of the Thyroid in Mice Shown by Microautoradiography
Authors: Slanina Premysl , Tjälve Hans 
Published: December 2008

AbstractMale albino mice were injected with 3H‐atropine and killed 5 min, 30 min and 2 h after the injection. The distribution of radioactivity in the pancreas and the thyroid was then studied with a microautoradiographic technique for isotopes in water soluble form. In the pancreas the highest radioactivity was found in the pancreatic islets. In the thyroid the radioactivity was most strongly accumulated in cells with a distribution corresponding to the parafollicular cells. A method for a combination of monoamine fluorescence with microautoradiography was also used to show that the cells of the pancreatic islets and the parafollicular cells of the thyroid, which are capable of monoamine accumulation after monoamine‐precursor injection, also are capable to accumulate atropine.
The Oxygen Supply to the Retina, I. Effects of Changes in Intraocular and Arterial Blood Pressures, and in Arterial PO2 and Pco2 on the Oxygen Tension in the Vitreous Body of the Cat
Authors: Alm Albert , Bill Anders 
Published: December 2008

AbstractThe Po2 in the vitreous body close to the retina, PvrO2, was determined continuously with an O2 electrode. In cats with a mean arterial blood pressure of 176±7 cm H2O, a PaO2 of 98±2 mm Hg, a PaC02 of 27.0±1–2 mm Hg and a pH of 7.43±0.16 units the mean PVr02 was 18.9±1.5 mm Hg. Stepwise increments in the eye pressure had no effect on PVrO2 at perfusion pressures above 50–100 cm H2O. At lower perfusion pressures PvrO2 decreased. Changes in perfusion pressure caused by hemorrhage and retransfusion gave similar results. At low Paco2 levels PvrO2 decreased; at high PaCo2 levels values of 40–60 mm Hg were observed. Reductions in Pao2 decreased Pvro2, increments gave either no change or a rise in Pvr02‐ Hypercapnia combined with high Pao2 in several cases resulted in PVr02 values between 100 and 150 mm Hg. The results indicate that the blood flow through the retina is very efficiently autoregulated, that oxygen tends to induce vasoconstriction in the retinal blood vessels, that hypocapnia gives vasoconstriction and hypercapnia marked vasodilatation.
Storage of 5‐Hydroxytryptamine in Rat Mast Cells. Evidence for an Ionic Binding to Carboxyl Groups in a Granule Heparin‐Protein Complex
Authors: Bergendorff Anders , Uvnas Borje 
Published: December 2008

AbstractBergendorff, A. and B. Uvnas.Storage of 5‐hydroxytryptamine in rat mast cells. Evidence for an ionic binding to carboxyl groups in a granule heparin‐protein complex.Acta physiol. scand. 1972.84.320–331.Basophil granules were isolated from rat peritoneal and thoracic mast cells. The granules were depleted of their endogenous Hi and 5‐HT and the amine storing properties of these depleted granules were studied. The influence of pH, the uptake capacity, the releasing action of sodium ions and the competitive uptake of Hi and 5‐HT by the granule stores all support the hypothesis that the granule stores have the properties of a weak cation exchange resin. It appears that 5‐HT release, as we previously showed for Hi‐release, is due to a cation exchange occurring on mast cell degranulation, when the amine‐containing granules become exposed to cations of the extracellular milieu.
The Influence of the Crowding Phenomenon on the Oxygen Consumption of Blood Cells as Determined by the Cartesian Diver Technique
Authors: Talstad Ingebrigt 
Published: December 2008

AbstractTalstad, I. The influence of the crowding phenomenon on the oxygen consumption of blood cells as determined by the Cartesian diver technique. Acta physiol. scand. 1972. 84. 332–337.The tendency of decrease in oxygen (O2)‐consumption per cell with increase in cell concentration during measurements (crowding phenomenon) was studied with the Cartesian diver technique. The theoretical linear relationship between O2‐consumption and the number of ceils was found for polymorphonuclear leukocytes (PMN), lymphocytes and platelets with the standard divers, the capillar) type of divers giving the same results as standard divers. However, marked crowding phenomenon occurred at high numbers of PMN, lymphocytes or platelets per diver. An explanation for the crowding phenomenon is probably deficient O2‐equilibration during measurements and not a peculiar phenomenon of PMN or lymphocytes as has so far been suggested.
The Glomerular Filterability of Inulin and of Different Molecular Weight Preparations of Polyethylene Glycol in the Rabbit
Authors: Jorgensen K. E. , Møller J. V. , Sheikh M. I. 
Published: December 2008

AbstractJorgensen, K. E., J. V. Møllerand M. I. Sheikh. The glomerular filterability of inulin and of different molecular weight preparations of polyethylene glycol in the rabbit. Acta physiol. scand. 1972. 84. 408–414.It has been claimed on the basis of clearance experiments that inulin is incompletely filterable through the glomerular membrane of the rat kidney (Berglund 1964, 1965). In the present study the renal excretion in the rabbit of inulin and different preparations of polyethylene glycol has been compared during constant infusion of these substances. Identical clearance values were obtained for inulin and polyethylene glycol, having molecular weights of 1500 (PEG–1500) and 4000 (PEG–4000). The ratio of the clearances between polyethylene glycol of a molecular weight of 6000 (PEG–6000) and inulin was smaller than unity (0.89±0.03). Gel filtration analysis of plasma and urine samples indicated unrestricted filtration of inulin through the glomerular membrane of this species. Furthermore, gel filtration and ultrafiltration experiments indicated that the molecular size of inulin and PEG–1500 is similar, while the molecular dimensions of PEG–6000 exceed that of the most high molecular weight fractions of inulin. It is concluded that the clearance of inulin, PEG–1500, and PEG–4000 may be used as a measure of the glomerular filtration rate in the rabbit, whereas the glomerular filtration of PEG–6000 is restricted to some extent. The incomplete filterability of PEG–6000 is attributed to the relatively larger molecular size.
Convergence of Large Muscle Spindle (Ia) Afferents at Interneuronal Level in the Reciprocal Ia Inhibitory Pathway to Motoneurones
Authors: Hultborn H. , Udo M. 
Published: December 2008

AbstractIt has earlier been established that in a number of motor nuclei la inhibition can be evoked from several muscles. It has now been investigated if this convergence takes place already at the interneuronal level or if the la inhibition from the different muscles is exerted through separate interneuronal pools which then converge at motoneuronal level. With intracellular recording from motoneurones and utilizing the technique of spatial facilitation it has been demonstrated that when activity in la afferents from several muscles can evoke inhibition in a given motoneurone a convergence of these la afferents does occur onto common interneurones.
Cerebrospinal Fluid Clearance of Choline and Some Other Amines
Authors: Aquilonius Sten‐Magnus , Winbladh Birger 
Published: December 2008

AbstractThe elimination from CSF of the quaternary ammonium compounds choline, methylatropine and decamethonium and the tertiary amine atropine has been investigated by ventriculo‐cisternal perfusion in anesthetized dogs and rabbits. The elimination of the amines from the perfusate was partly concentration dependent. Further, in the rabbit experiments they decreased the elimination of each other. In the dog 63 per cent of the infused choline was eliminated between the lateral ventricle and cisterna magna at an infusate concentration of 5·10‐‐6M and a rate of 150 μl/min. The corresponding figure for the rabbit was 78 per cent at 30 μl/min. Brain drug concentrations after the experiments revealed that diffusion into the brain contributed to the elimination only to a minor extent. Results were compared to invitrostudies on choroid plexa. A correlation was found between the rate of removal from perfusate for the quaternary drugs and their uptake characteristicsin vitro. The conclusion was drawn that the investigated amines are eliminated from CSF partly by a carrier mediated process. One important site of this process is probably the choroid plexus.
Utilization of Yolk Cholesterol in the Developing Chick Embryo
Authors: Jain Shashi Kumar , Lindahl Per Eric , Svanberg Olof 
Published: December 2008

Abstract 14C‐4‐cholesterol was injected into fertilized hens' eggs after different incubation times. The embryos were removed after various times and subjected to auto radiographic examination. By tracing the label at subsequent stages of development, the time sequence for the utilization of the pre‐formed yolk cholesterol has been determined. Up to the 8th day of incubation the cholesterol from the yolk was homogeneously distributed in the embryo, with a slightly higher concentration in the peripheral parts of the spinal cord and in the some areas of the brain. Two days later a slight elevation of the liver 14C‐cholesterol concentration occurred, followed by a rapid increase after the 15th day. Bile was first secreted on the 11th‐12th day. The incorporation of 14C‐cholesterol into the central nervous system was partly restricted after the 8th day. From the 15th day hardly any labelled cholesterol was incorporated in the brain and spinal cord; a specific blood‐brain barrier had been established. The peripheral nerves, however, were intensively labelled by the 19th day. By this time the adrenals and the gonads contained more labelled cholesterol than other tissues.
Increased Activity in Left Ventricular Receptors during Hemorrhage or Occlusion of Caval Veins in the Cat. ‐ A Possible Cause of the Vaso‐vagal Reaction
Authors: ÖBerg Bengt , Thorén Peter 
Published: December 2008

AbstractImpulse activity in vagal afferent fibres and changes in heart rate were simultaneously recorded during rapid hemorrhage or blood pooling in cats in order to elucidate whether the sudden reflex bradycardia, sometimes evoked with the mentioned interventions, was correlated to an increased activity in any type of heart receptors. The results show that the slowing of the heart, resulting from an emptying of the central blood reservoirs was correlated to, and preceded by, an increased activity in receptors located in the left ventricle and signalling in non‐medullated afferents. The receptors were found to be activated also by obstructions of the ascending aorta and mechanical stimulation of the heart, and therefore seem to operate as mechanorecepton, stimulated by a “distortion” of the myocardium. ‐ It is conceivable that with rapid bleeding or pooling of blood, the receptors are excited by an improper squeezing of the myocardium when the ventricles contract vigorously around an almost empty chamber, and then induce a reflex bradycardia. This reflex mechanism, resembling the so‐called vaso‐vagal syncope reaction in man, may therefore serve as a protective system causing a break on the heart and allowing for an improved diastolic filling in situations when venous return is critically reduced.
The Influence of Deep Barbiturate Anesthesia upon the Regulation of Extra‐ and Intracellular pH in the Rat Brain during Hypercapnia
Authors: Messeter Kenneth , Pontén Urban , Siesjö Bo K. 
Published: December 2008

AbstractIn order to study the influence of deep barbiturate anesthesia upon the regulation of extra‐ and intracellular pH in the brain, hypercapnia was induced in rats anesthetized for maximally three hrs with either 200–250 mg/kg of phenobarbital, or with 0.6 % halothane. There were no differences in the regulation of the CSF pH between the groups studied. However, both at 15 min at and 3 h the phenobarbital anesthesia was associated with a less efficient regulation of the intracellular pH'. At 15 min the regulation observed came close to that expected on the basis of pure physicochemical buffering. It is concluded that deep phenobarbital anesthesia, probably due to its effect on metabolism, can interfere with the mechanisms which regulate intracellular pH' during hypercapnia.
Hemodynamic Responses of Relaxed, β‐Blocked and Shivering Dogs during Hypothermia
Authors: Halkola Lauri , Koivikko Antti , Länsimies Esko 
Published: December 2008

Abstract7 dogs were anesthetized only, ten dogs anesthetized and relaxed. Additionaly three dogs were anesthetized, relaxed and β‐blocked. All dogs were ventilated by oxygen. Hypothermia was produced by ice‐water immersion. The oxygen consumption decreased in all but the shivering group. Initially, the cardiac output increased in the shivering group, decreased in the β‐blocked group but an unexpected slight increase was observed in the relaxed group. The reason for this observation is being discussed.