bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circulatory and Behavioural Effects on Electrical Stimulation of the Sympathetic Vasodilator Areas in the Hypothalamus and the Mesencephalon in Un anesthetized Dogs
Authors: Bolme Per , Ngai S.H. , Uvnäs Börje , Wallenberg Lars R. 
Published: December 2008

AbstractBlood prrssure, heart rate, blood flow to the hind limb and behaviour wcrv studied in conscious dogs during topical stimulation of the sympathetic vasodilator outflow area in the hypothalamus and the mesencephalon. The responses obtained on stimulation were: a rise in blood pressure, tachycardia and also an increasr in hind limb blood flow which could bc abolished by atropinc. The effects on circulation caused by stimulation were essentially the same in the conscious and the anaesthetized dog. The behavioural changes on stimulation were relatively small and consisted of variations in the degree of alertness. In many experiments marked circulatory responscs were obtained on stimulation without any apparent behavioural reactions. Whether these findings indicate that the cholinergic vasodilator system acts more generally in circulatory homeostabis or is restricted to participation in specific situations ase.g. adjustments preparatory to niuacle effort. is discussed.
Projections of the Eye and the Neck Region on the Anterior Suprasylvian Cerebral Cortex of the Cat
Authors: Landgren S. , Silfvenius H. 
Published: December 2008

AbstractThe overlap between projections of visual, auditory, cutaneous and muscle afferents to the cerebral cortex of the anterior suprasylvian sulcus was studied in cats anesthetized with chloralose. The visual projections were found near the junction between the anterior and the middle suprasylvian sulcus. They overlapped in rostral direction with the auditory projection area in the lower bank of the anterior sulcus. The overlap was, however, not complete and large click potentials, but no response to a light flash, were recorded in the lower bank just caudal to the locus of the Group I muscle afferents. Low threshold cutaneous and high threshold muscle afferents from the neck projected to the anterior suprasylvian and ecto‐sylvian gyri and to the upper bank of the anterior suprasylvian sulcus. Low threshold rnuscle and cutaneous neck afferents projected to the postcruciate dimple. A hypothesis concerning the function of this cortical region is discussed.
Formation of Extracellular Adenosine Triphosphate by Yeast Cells
Authors: ÅGren Gunnar , Ronquist Gunnar 
Published: December 2008

AbstractYeast cells were incubated with the necessary substrates and cofactors of the glyceraldehyde‐3‐phosphate dehydrogenase and phosphoglycerate kinase reactions (complete system) and also with an incomplete system lacking the phosphorylaied substrates and cofactors. Ten times more ATP was formed by the yeast cells incubated with the complete system as compared with those incubated with the incomplete system. All the resulting ATP formed by the phosphorylated substrates and cofactors present in the complete system could be recovered in the extracellular medium. Only an insignificant part of this ATP has probably been formed by enzymes of intracellular origin. It is reasonable to assume that most of the ATP present in the extracellular medium has been formed by the enzymes located on the surface of the yeast cells.
Proximal Luminal Volume and Fluid Reabsorption in the Rat Kidney1
Authors: Baines Andrew D. , Gottschalk Carl w. , Leyssac Paul P. 
Published: December 2008

AbstractThe relationship between proximal luminal volume and proximal salt and water reabsorption was studied in 21 non‐diuretic anesthetized male rats. Luminal diameters were measured in enlarged photographs of the surface of the capsulated kidney. Proximal reabsorption rates were estimated from Cin, which changed spontaneously in the range 0.4–1.6 ml/min g kidney weight (k.w.). Cin was further reduced in eight rats by compression of the renal artery. The mean proximal luminal diameter was 18.7 μ without compression of the renal artery and 19.6 μ during compression. There was no consistent relationship between estimated proximal reabsorption rate and proximal luminal diameter. It is concluded that proximal tubular volume was not the prime determinant of proximal salt and water reabsorption rate in rats under the conditions of these experiments.
Formation of Extracellular Adenosine Triphosphate by Human Erythrocytes
Authors: Ronquist Gunnar 
Published: December 2008

AbstractThe formation of extracellular adenosine triphosphate by human erythrocytes was studied. The red cells were incubated with (32P)‐orthophosphate, together with all necessary substrates and co‐factors of the glyceraldehyde‐3‐phosphate dehydrogenase and phosphoglycerate kinase reactions (complete system), and also with an incomplete system lacking the phosphorylated substrates and cofactors. Finally, the red cells were incubated with the complete system lacking only one phosphorylated cofactor. All incubations were performed under isotonic conditions.At I min incubation, three times more AP32P was formed by the red cells incubated with the complete system than with those incubated with the incomplete system. All the resulting AP32P formed by the added phosphorylated substrates and cofacton present in the complete system could be recovered in the extracellular medium. Only an insignificant part of this AP32P was probably formed by enzymes which were eluted out into the surrounding medium. It is therefore reasonable to infer that most of the AF32P present in the extracellular medium was formed by the enzymes located on the surface of the red cells. No AP32P was found in the extracellular medium of red cells incubated with the incomplete system, nor with the complete system lacking only one phosphorylated cofactor. Thus, none of the intracellular ADP, NAD+ or glyceraldehyde‐3‐phosphoric acid could be utilized in ATP formation on the red cell surface.
Some Factors Influencing the Stimulatory Effect of Ethanol on Gastric Acid Secretion during Antrum Application1
Authors: Elwin Carl‐Eric 
Published: December 2008

AbstractVariations in gastric secretory response to antral application of ethanol were studied in Heidenhain and Pavlov pouch dogs with isolated, innervated antral pouch, to disclose the influence of instillation pressure, temperature, concentration, pH and ion composition. Secretory response increased in 2 of 5 dogs and remained unchanged in 3 dogs during rise of installation pressure from 0 cm H2O to 20–30 cm H2O. Secretory responses were essentially alike, whether alcohol solutions were administered at room temperature or at body temperature. Threshold stimulatory concentration was 2–4% (v/v), optimal effect occurred at 8–16%, a decrease was usually observed at 32%. Antrum pouches were perfused with buffered ethanol solutions at pH values between 7.0 and 1.0. No significant difference of the stimulatory effect was noted within the pH range 7.0–3.0. At pH 2.0 the stimulatory action was decreased by about 40% and at pH 1.0 almost totally suppressed. The slope of the pH curve seems to be independent of the ethanol concentration. The pH curves for the stimulatory effect of alcohol in the antrum and for vagus stimulation are almost identical. The ethanol effect was inhibited by high concentrations of K+ and Ca++ but uneffected by corresponding concentrations of Na+ and Mg++.
Three Different Systems of Monoamine‐Storing Cells in the Gastrointestinal Tract of Fetal and Neonatal Rats
Authors: Håkanson R. , Owman Ch. , Sjöberg N.‐O. 
Published: December 2008

AbstractThe development of three monoamine‐storing cell systems in the wall of the duodenum, glandular portion of stomach, and ileum has been followed histochemically in fetal and newborn rats, and compared with the number and characteristics of such cells in adults. 5‐Hydroxy‐tryptamine can be demonstrated in mast cells and enterochromaffin cells already a few days before birth. Part of the mast cell population, i.e. the one which in adult animals is found as “atypical” mast cells near the mucosal surface, is able to take up high amounts of L‐DOPA. “Enterochromaffin‐like” cells, exclusively found in the oxyntic gland area of the gastric mucosa, are also able to take up and, probably decarboxylate, L‐DOPA already at birth. Their number increases progressively in the following stages. Gastric DOPA decarboxylase activity is high already at a stage when the capacity to store monoamines has not yet developed in the enterochromaffin‐like cells, the system of monoamine cells quantitatively dominating in the stomach wall. The finding suggests that DOPA decarboxylase occurs also in other cell systems, such as mast cells and enterochromaffin cells, which are capable of storing monoamines earlier than the enterochromaffin‐like cells. The activity of gastrointestinal DOPA decarboxylase reaches adult levels already by the time of birth, and is probably primarily associated with the two systems of enterochromaffin and enterochromaffin‐like cells.
Vago‐Vagal Reflex Relaxation of the Stomach in the Cat
Authors: Jansson Gunner 
Published: December 2008

AbstractIn acute experiments on chloralosed cats gastric motility was recorded with a rubber balloon system kept at constant intragastric pressure under experimental conditions not requiring abdominal surgery.‐Electric stimulation of the central end of either a small vagal branch at the level of the diaphragm or of one vagal nerve at the level of the neck, while the opposite vagal nerve was left intact produced profound reflex relaxation of the stomach. Also the efferent pathway of the relaxatory reflex was in the vagal nerves.‐The reflex relaxation persisted after administration of atropine, which shows that it was not due to reflex suppression of prevailing activity of the vagal cholinergic motor fibres. It was also independent of adrenergic mechanisms, since it persisted after administration of guanethidine in doses known effectively to block the adrenergic intestino‐gastric inhibitory reflex. This vago‐vagal relaxatory reflex response thus showed the same characteristics as the gastric response elicited by efferent stimulation of the high‐threshold vagal relaxatory fibres.‐It is concluded that this vago‐vagal reflex originates, at least partly, from abdominal structures, with the efferent pathway consisting of the relaxatory, high‐threshold fibres producing pronounced gastric relaxation. This vago‐vagal relaxatory reflex may be involved in receptive relaxation of the stomach.
Effects of Bicarbonate and Thiocyanate on Fluxes of Na and K, and on Glucose Metabolism of Actively Transporting Human Red Cells
Authors: Wieth Jens Otto 
Published: December 2008

AbstractIt has been shown in a previous work that sodium influx is trebled, whereas potassium efflux is slightly reduced, when erythrocytes are suspended in a 142 mM bicarbonate medium containing ouabain. The present work deals with the active transport of sodium and potassium occurring in the presence of 142 mM bicarbonate (38° C, pH 7.40). Sodium influx and potassium efflux were unaffected by the removal of ouabain, whereas sodium efflux, potassium influx, and glucose metabolism were all strongly stimulated. The relation between ouabain sensitive ion transport and the calculated extra formation of ATP was 3.1 moles Na/mole ATP and 2.3 moles K/mole ATP, in agreement with values previously found on red cells transporting Na and K in plasma. Red cells incubated in the bicarbonate medium accumulated potassium until extracellular potassium concentration had been reduced to 1.8–2 mM. The normal volume regulation of the cells was severely interfered with, because accumulation of sodium and potassium was accompanied by a net flux of water of 6 g per meq cation. All effects observed could be interpreted to be secondary to the increased sodium influx, leading to an increase of intracellular sodium concentration, which in turn stimulated active cation transport, thereby accelerating the rate of ATP turn‐over. The properties of the ouabain sensitive transport mechanism were not affected by the presence of bicarbonate.Both potassium efflux and sodium influx are increased by 200–300 per cent in the presence of 120 mM thiocyanate. It was found, however, that active cation transport is not stimulated in a 120 mM thiocyanate medium. On the contrary the ouabain sensitive ion transport was steadily decreasing during incubation in spite of conditions otherwise favouring transport of Na and K, i.e. increasing extracellular potassium and intracellular sodium concentrations.
A Sound‐Attenuating, Electrically Shielded Chamber for Experiments in Sensory Physiology
Authors: Bergström R. M. , Blåfield R. , Fruhstorfer H. , Hytönen Y. , Jauhiainen T. 
Published: December 2008

AbstractThe construction of a sound‐attenuating, electrically shielded chamber for experiments in sensory physiology is reported in short. The values of sound attenuation are given. Electrical shielding and connection to the laboratory computer are explained.
Tubular Sodium Reabsorption and the Regulation of Renal Hemodynamics. The Effect of Hypertonic Saline Infusion on Renal Vascular Resistance
Authors: Aperia Anita C. , Liebow Averill A. , Roberts Lathrop E. 
Published: December 2008

AbstractThe hemodynamic response following saline loading was found to differ from that induced by the saluretic agent, chlorothiazide, which causes vasoconstriction. When hypertonic NaCl was infused into the renal artery until a profuse sodium diuresis was obtained, and the infusion then interrupted, CNa/CIn remained elevated for 60–80 min. During this period the renal vascular resistance did not change significantly and the glomerular filtration rate tended to rise as compared with the control periods. This is contrary to what has previouly been found during chlorothiazide administration, where renal vascular resistance was significantly correlated with CNa/CIn. A hypertonic saline load blocks Na reabsorption in the proximal tubules, chlorothiazide mainly in the distal tubules. It was therefore concluded that it is a reduction of movement of Na into the distal tubule cells, specifically the macula densa, rather than the increased Na concentration of the distal tubular fluid that is responsible for the vasoconstrictive effect of chlorothiazide.
Relationship between Aortic Diameter and Aortic Baroreceptor Activity in Normal and Hypertensive Rabbits
Authors: Aars Harald 
Published: December 2008

AbstractStudies of aortic nerve activity (Aars 1968a), and the load/length relationship of strips from the aortic wall (Aars 1968b), have suggested that the hypertensive resetting of baroreceptor activity is due to changes in the aortic wall. In nine normal and four hypertensive rabbits, diameter of the ascending aorta, measured with an ultrasonic gauge, was therefore recorded together with aortic baroreceptor activity. Aortic nerve activity was closely related to aortic diameter in individual rabbits, but wide variations in pressure/diameter relationships made it difficult to compare diameter and activity in a group of rabbits. Assuming that stretching of the receptor area would be almost equal in all rabbits at the inflexion point of their pressure/diameter curves, the diameter corresponding to inflexion point of the curve for dynamic elastic modulus was used as reference diameter. Plotted against per cent of this diameter, the nerve activity showed acceptable uniformity in the group of normal rabbits, and observations in hypertensive rabbits showed less deviation from the normal. The uniformity was further improved by allowing for variations in diameter pulsations. It was therefore concluded that the hypertensive resetting of aortic baroreceptor activity was predominantly due to altered distensibility of the aortic wall.
Electrical Stimulation of a Human Ventrolateral‐Subventrolateral Thalamic Target Area
Authors: Johansson Gunnar G. 
Published: December 2008

AbstractA ventrolateral‐subventrolateral thalamic target area was electrically stimulated in connection with stereotaxic neurosurgery in 20 alert Parkinsonian patients and in 4 patients with hereditary intention tremor. The study forms part of a larger investigation concerned with the effect of different stimulus parameters on the clinical responses evoked by stimulation. Here unidirectional square wave pulses with a constant peak current and repetition frequencies ranging from 1 to 200 pulses per second were applied. The stimulation was kept at the threshold for clinical responses by balancing the different repetition frequencies with the pulse duration. Stimulation elicited motor and “sensory” responses. The character of the responses depended on the pulse repetition frequency used. The localization in the body of the projected threshold responses, on the other hand, depended on the pulse duration used. The pulse duration‐pulse repetition frequency relationship at the threshold for evoking clinical responses is shown. The results are discussed.
Effect of Acid in the Duodenal Bulb on Gastric Secretory Responses to Insulin Hypoglycemia1
Authors: Nilsson Göran 
Published: December 2008

AbstractGastric acid secretion was stimulated by insulin hypoglycemia in Pavlov pouch dogs with isolated pouches of the duodenal bulb. Perfusion of the duodenal bulb with 0.1 N HCI abolished the secretory response to a low dose of insulin (0.2 I.U. per kg b.w.), whereas the responses to higher doses (0.4 and 0.8 I.U. per kg b.w.) were only partially inhibited. It is suggested that the bulbar mechanism inhibits secretory responses to insulin hypoglycemia by interference with the stimulatory action of gastrin.
Evidence for a Hypothalamic Control of Renal Sodium Excretion
Authors: Andersson B. , Dallman M. F. , Olsson K. 
Published: December 2008

AbstractSlow infusions (7.5 μl/min) of hypertonic NaCl into the 3rd brain ventricle of goats maintained on a NaCl‐supplemented diet provoked natriuresis reaching maximum about 70 min after onset of the infusions. The natriuresis was less pronounced in animals receiving no dietary NaCl‐supplementation. The magnitude of the natriuretic response was dependent on the molarity of the NaCl infused and on infusion duration. A much smaller relative increase in K excretion, reaching peak values 20 min before maximum natriuresis, also occurred. Aldosterone treatment did not prevent the natriuretic response and it could be elicited in diabetes insipidus animals, showing that release of posterior pituitary hormones was not essential. Determinations of inulin clearance (CIn) indicated that glomerular filtration rat (GFR) increased and that relative reabsorption of Na+ decreased during the natriuresis.Similar intraventricular infusions of hypertonic NH4Cl resulted in greatly diminished renal Na+ excretion lasting for about 2 hrs. Such infusions also delayed by 90 min the normal natriuretic response to an intravenous NaCl load. CIn determinations indicated that a diminished GFR may have contributed to this reduction in renal Na+ excretion. The results indicate that renal Na+ excretion is under hypothalamic control in the goat. Possible mechanisms for this control are discussed.
Transient Transmembrane Water Movements in Crayfish Axons Detected by Transmitted Light Interference Microscopy
Authors: Lieberman E. M. 
Published: December 2008

AbstractTransmitted light interference microscopy is shown to be a sensitive technique for detecting email transient changes in optical path differences of axons during and following electrical stimulation. It is tentatively concluded that water enters the axon during and following tetanizing stimulation and that this event is in accord with earlier findings concerning opacity changes under similar experimental conditions. It was further demonstrated that the membrane of the axon is normally under a hydrostatic pressure difference of approximately 2 cm of H2O and this may be a contributing factor to the optical properties of the axon during the excitation process.
Descending Monosynaptic and Reflex Control of γ‐Motoneurones
Authors: Grillner S. , Hongo T. , Lund S. 
Published: December 2008

AbstractThe supraspinal and reflex control of γ‐motoneurones has been studied with intra‐ and extracellular recording from lumbosacral γ‐motoneurones in the cat. Monosynaptic EPSPs were recorded in some γ‐motoneurones on stimulation of the brain stem. These effects were evoked from the Deiters' nucleus and from fibres descending in the medial longitudinal fascicle probably originating in the pontine reticular formation. Previous investigations have revealed monosynaptic connections to α‐motoneurones from these regions and our results suggest parallel effects to α‐ and part of the γ‐motoneurone population supplying one muscle. Indirect evidence suggests that this monosynaptic effect is exerted only on static γ‐motoneurones, thus implying a linkage between the descending monosynaptic control of α‐ and static γ‐motoneurones via these pathways. The reflex effects to γ‐motoneurones have been studied with graded electrical stimulation of ipsi‐ and contralateral hindlimb nerves. Five γ‐motoneurones, presumably all belonging to extensor motor nuclei, were found to receive IPSPs from group I afferents and it is suggested that only static γ‐motoneurones are influenced. It has not been possible to decide if these IPSPs are evoked from Ib or Ia afferents. The reflex effects from group II and III muscular afferents, joint and cutaneous afferents seem to conform to the effects evoked in α‐motoneurones from these afferents.
Brain Monoamines in the Temperature Acclimation of Mice
Authors: Harri M. , Tirri R. 
Published: December 2008

AbstractThe brain 5‐hydroxytryptamine (5‐HT) and noradrenaline (NA) levels were determined fluorimetrically from mice during prolonged exposure to cold or heat. The NA level did not change until at extreme ambient temperatures, in which cases, especially in heat, a marked decrease was observed. In cold environment the 5‐HT level decreased after an initial short increase. However, within one day the initial control level was reached again. In warm environment the changes were reversed. Some depletion experiments, where an inhibitor of 5‐HT synthesis was used, showed that the activity of brain 5‐HT neurons decreased for some days in cold, but returned gradually to the control level after the animals had acclimated to cold.
Cerebrospinal Fluid Perfusion, A Method for the Study of Neurosecretory Organs
Authors: Hirvonen J. , Karlsson L. K. J. , Salorinne Y. 
Published: December 2008

AbstractThe cerebrospinal perfusion method was applied for the study of the hypothalamo‐neurohypophyseal secretory system and subcommissural organ in the cat and rat. The artificial cerebrospinal fluid was introduced into the lateral ventricle and taken out of the suboccipital cisterna. Hyperkalemic (8 meq/1) perfusion fluid effected a decrease of the aldehyde‐fuchsin‐positive material in the subcommissural organs of the cats and rats. Hyperosmotic perfusion fluid had such an effect neither on the neurohypophysis nor the subcommissural organ. The method seems usefull for the study of the cellular reactions of the neurosecretory organs in vivo.