bluuebunny/crossref_metadata_2025 huggingface dataset:
The Adaptation and the Relation between Discharge Frequency and Current Strength of Cat Lumbosacral Motoneurones Stimulated by Long‐Lasting Injected Currents
Authors: Kernell Daniel
Published: December 2008

Kernell, D. The adaptation and the relation between discharge frequency and current strength of cat lumbosacral motoneurones stimulated by long‐lasting injected currents. Acta physiol. scand. 1965. 65. 65–73. — Cat lumbosacral motoneurones were stimulated by steady currents injected through the tip of an intracellular micro‐electrode. The results strongly indicate that the majority of undamaged motoneurones are capable of responding to steady currents by long‐lasting and well maintained repetitive discharges. Such discharges from various motoneurones were studied with regard to the adaptation and the slope of the linear relation between discharge frequency and current strength (cf. Granit, Kernell and Shortess 1963 a, b). Measurements were also made of the lowest current strength (in units of rheobase) which was needed for eliciting a steady repetitive discharge. None of these characteristics relating to repetitive firing were found to be correlated with the duration of afterhyperpolarization, the latter being measured by single spike discharges (generally antidromic). The results have been discussed also with reference to earlier findings concerning tonic and phasic repetitive firing of motoneurones stimulated by muscle stretch.
The Limits of Firing Frequency in Cat Lumbosacral Motoneurones Possessing Different Time Course of Afterhyperpolarization
Authors: Kernell Daniel
Published: December 2008

Kernell, D. The limits of firing frequency in cat lumbosacral motoneurones possessing different time course of after hyperpolarization. Acta physiol. scand. 1965. 65, 87–100. — Long‐lasting repetitive discharges were set up in cat lumbosacral motoneurones by steady currents injected through the tip of an intracellular micro‐electrode. The upper and lower limits of discharge frequency of the various motoneurones were significantly correlated with the time course of their afterhyperpolarization the latter being measured from single spike discharges (generally antidromic). From previous work it is known that the relation between discharge frequency and current strength (the “f‐I relation”) is linear over a certain range from the minimal firing rate and upwards (Granit, Kernell and Shortess 1963, Kernell 1965 b). In the present paper it was shown that the maximal discharge frequency within this linear part of the f‐I relation was also significantly correlated with the time course of afterhyperpolarization. The findings are discussed with regard to problems of regulation of muscle tension by repetitive firing on the part of the motoneurones.
The Distribution in the Mammal Body of F18 and P32 from Double‐Labelled Na2PO3F
Authors: Ericsson Yngve , Hammarström Lars
Published: December 2008

Ericsson, Y. and L. Hammarström. The distribution in the mammal body of F18and P32 forn double‐labelled Na2PO3F. Acta physiol. scand. 1965.65. 126–137. — Autoradiographic and quantitative investigations with F18, P32‐labelled Na2PO3F were performed on mice and rats in order to study the fate of the monofluorophosphate ion in the mammal body. Comparisons were made with the distribution of F18 as fluoride ions and P32 as orthophosphate ions. Intravenous injection of the double‐labelled POF ion gave strikingly high concentrations of F18 in the intestinal lumen and of P32 in the intestinal wall. A comparatively high concentration of F18 was found in the liver following the ingestion as the PO3F ion. Fluorine ingested as the monofluorophosphate ion did not pass the placenta to any greater extent than when given as the fluoride ion. The indications of these data for further studies of the site and mechanism of splitting and toxicity of monofluorophosphate are discussed.
The Effect of Ethyl Alcohol on Non‐Gustatory Receptors of the Tongue of the Cat
Authors: Hellekant Göran
Published: December 2008

Hellekant, G. The effect of ethyl alcohol on non‐gustatory receptors of the tongue of the cat. Acta physiol. scand. 1965. 65. 243–250. — Recordings were made of the response in the trigeminal part of the lingual nerve of the cat to the application on the tongue of alcohol, gustatory, thermal and mechanical stimuli. The summated response to alcohol revealed a slowly increasing dischargc after a latency of a few sec. The magnitude of the response increased with increasing alcohol concentrations and attained a maximum at 4 to 5 M alcohol then decreased at higher concentrations. The response of single lingual nerve fibres was also recorded. None of the fibres investigated responded to NaCl, acetic acid or quinine. All fibres responding to alcohol responded also to cooling and mechanical stimulation. The threshold alcohol concentration in the majority of these fibres was about 2.5 M. These fibres displayed a very regular discharge which reached an average maximum frequency of 38 imp/sec at 4.1 M alcohol. A reversible paralysis of the receptors was usually observed at alcohol concentrations of 4.1 M or higher. The conduction velocities of these fibres ranged from 5.7 to 18.0 m/sec. Alcohol did not stimulate myelinated mechanoceptive fibres which responded selectively to light or deep pressure on the tongue (specific mechanoceptive fibres) nor did alcohol stimulate myelinated fibres which only responded to high threshold mechanical or thermal stimulation (specific nociceptive fibres).
Hydrolysis of Adenosinetriphosphate and Creatinephosphate on Isometric Contraction of Vascular Smooth Muscle
Authors: Beviz Andras , Lundholm Lennart , Mohme‐Lundholm Ella , Vamos Nandor
Published: December 2008

Beviz, A., L. Lundholm, E. Xiohme‐Lundholrn and N. Vanios. Hydrolysis of adenosinetriphosphate and creatinephosphate on isomdric contraction of vasculur smooth muscle. Actaphysioi. scand. 1965. 65. 268–272. In experiments on isolated bovine mesenteric artery the adenosinetriphosphate (ATP) and creatinephosphate (CrP) contents were determined after isometric contraction by adrenaline. 1 min after addition of adrenaline (1.10‐6) when the rise of tension was one‐half maximum, the ATP content had fallen by 0.16 ± 0.07 μmoie/g of tissue and the CrP content by 0.22 ± 0.07 μmole. At the end of 7 min, when the elevation of tension was maximal, hydrolysis of ATP amounted to 0.37 ± 0.10 μmiole and that of CrP to 0.40 ± 0.09 μmole/g of tissue. There was no definite change of the adenosinediphosphate (ADP) or adenosinemonophosphate (AMP) content. When adrenaline had exerted its action for 60 min and the tension was still at maximal level: the ATP content did not differ from that in the controls, whereas the CrP content was still reduced by 0.52 ± 0.18μmolelg of tissue. Calculation of the P.L/H quotient from the summed hydrolysis of ATP and CrP and the rise in tension during the first minute of contraction, gave a value of 9.5. This value was of similar magnitude to that found on thermoelectric determination of the heat production associated with isometric contraction of striated and smooth muscle.
Effects of Synthetic Angiotensin II on Catecholamine Levels and Biological Activity
Authors: Buckley Joseph P.
Published: December 2008

Buckley, J. P. Effects of synthetic angiotensin II on catecholamine levels and biological activity. Acta physiol. scand. 1965 65. 273–278. – Perfusion of synthetic angiotensin II did not alter the content of catecholamines in the isolated rabbit kidney and did not potentate the vasocon‐strictive effect of tyramine on the isolated perfused rabbit kidney. Angiotensin II did induce slow rhythmic alterations in perfusion pressure having a frequency of 2 to 3 per minute and pressure changes varying from 30 to 120 mm of water. Infusion of angiotensin II to anesthetized rats did not significantly alter the tissue content of catecholamines in the heart and kidney. The administration of angiotensin II via the carotid inflow to the recipient's head in dog cross circulation preparations in which the head was vascularly isolated from the trunk between C‐3 and C‐4 produced approximately a 50 % increase in the urinary excretion of adrenaline and no change in the excretion of noradrenaline in the recipient.
Influence of Dihydroergotamine and Adrenaline on the Concentrations of Glucose‐6–Phosphate, Fructose‐6–Phosphate, Adenosinetriphosphate and Creatinephosphate in Bovine Mesenteric Artery
Authors: Beviz A. , Mohme‐Lundholm E.
Published: December 2008

Beviz, A. and E. Mohme‐Lundholm. Influence of dihydroergotamine and adrenaline on the concentrations of glucose‐6–phosphate, fructose‐6–phosphate, adrenosinetriphosphate and creatinephosphate in bovine mesenteric artery. Acta physiol. scand. 1965. 65. 289–291. ‐ In experiments on isolated mesenteric artery dihydroergotamine (DHE) at a concentration of 1.10‐6. Raised the adenosinetri phosphate (ATP), creatine phosphate (CrP), glucose‐6–phosphate and fructose‐6–phosphate levels in the muscle preparations. On addition of adrenaline at a concentration of 1.10‐6. Following DHE, the muscle relaxed coincidently with a further rise of the ATP, CrP, glucose‐6–phosphate and fructose‐6–phosphate contents. Nethalide inhibited the relaxant effect of adrenaline. In experiments on preparations not treated with DHE, adrenaline contracted the muscle and reduced its ATP and CrP contents. Adrenaline thus appears to have stimulated receptors of two types: a‐receptors linked with arterial muscle contraction and hydrolysis of ATP, and β‐receptors associated with relaxation, synthesis of ATP, and stimulation of carbohydrate metabolism.
Tissue Eosinopenia in the jejunal Villi of the Isolated Loop during Resorption of Histamine, Acetylcholine and Adrenaline
Authors: Räsanen Torw
Published: December 2008

Räsänen,T. Tissue eosiriopenin in the jejunal rilli of the isolaied loop during resorption of histamine. acelylcholine and ndrenaline. Acta physiol. scand. 1963.65. 352–356. — Isotonic sodium chloride, isotonic potassium chloride. acetylcholine. histamine. adrenaline and dexamethasone were injected into the loop of the rat jejunum isolated with 2 ligatures. The circulation of the loop was intact. After an hour, specimens were taken from the isolated and intact jejunum for the count of tissue eosinophilic leucocytes and of the mucosal mast cells. Sodium and potassium chloride and dexamethasone did not cause any changes in the superficial tissue eosinophils of the lamina propria at the tip of the villi or in the basal tissue eosinophils of the lamina propria Superficial tissue eosinophilia decreased during the action of acctylcholine (P < 0.05) and histamine (P ‐<0.02). less markedly during the adrenaline effect. Basal tissue eosinophils inrreased in the free intestinal loop during the influence of rhe last‐mentioned arnine (P < 0.01). No changes occurred in the mucosal mast cell counts. It is suggested that eosinophilic leucocytes participate in the detoxication process with their perosidase enzyme stores and are destroyed.
Hydrogen Ion Concentration in the Gastric Juice after Pylorus Ligation in Dexamethasone‐Treated Rat
Authors: Haikonen Matti , Fäsänen Toimi
Published: December 2008

Haikonen. hf. and T. Räsänen. Hjdmgen ion concentration in the gstiic juice after pylurus ligation in dexamethason‐treated rot. Acta physiol. scand. 1963. 65. 378–382. — Rats were injected with dexaniethasone 3 × 1 mg at 12‐hr intervals before ligation of the pylorus. The hydrogen ion concentration of the gastric secreta. the volume of secretion and the amount of free HCI were measured 2 hrs after tying the ligature. The administration of dexaniethasone for 2 days before ligation of the pylorus inhibited gastric secretion during the ligation and elevated the pH of the secreta. No free HCl was demonstrated in it. Secretion was restored by histamine injected into the rats in connection with the application of the ligature. A single dose of dexamethasone 2 hrs before the application of the ligature caused elevation of gastric secretion.

It is suggested that the degranulation of the mast cells of the gastric Iiiucosa during dexamethasone therapy leads to inhibition of gastric secretion with the mucosa losing the histamine needed for its stimulation. This loss may he compensated by exogenous histamine. On the other hand. the histamine‐liberating property of dexamethasone enhances secretion when the de‐granulation of the mast cdls begins.
The Alveolar‐Arterial Oxygen Difference: Its Size and Components in Normal Man
Authors: Mellemgaard Kresten
Published: December 2008

Alveolar‐arterial oxygen tension difference and physiological dead space was measured in 80 normal subjects in resting conditions. A significant rise in both parameters with rising age was demonstrated. The composition of the alveolar‐arterial oxygen difference was studied by two independent methods of shunt measurement: Determination of alveolar‐arterial oxygen tension difference during oxygen breathing was used for measurement of the total venoarterial shunt, whereas analysis of the concentration of tritium (hydrogen) in arterial blood after intravenous injection of this gas in physical solution was employed as a measure of right‐to‐left shunt. It is concluded, that of the normal alveolar‐arterial oxygen difference only a small fraction is caused by right‐to‐left “anatomical” shunt in the lungs and less than half is caused by bronchial and thebesian vein drainage to the left side of the heart. The remaining part, which increases with age, must be due to inequalities in the distribution of ventilation/perfusion ratio in the lungs.
Intestinal Dipeptidases. IV. Studies on the Release and Subcellular Distribution of Intestinal Dipeptidases of the Mucosa Cells of the Pig
Authors: Josefsson Lars , Sjöström Hans
Published: December 2008

Dipeptidases are released very quickly (10–20 sec) from the mucosa cells of the pig small intestine when mucosa scrapings are placed into aqueous solution. The release is somewhat slower from intact pieces of the intestine but the enzymes are obtained in equal yields. Much higher values of specific activity are obtained this way than when the mucosa cells are homogenized. Distribution of the dipeptidases in the subcellular fractions of the mucosa cells has been determined. The activities are located in the supernatant fraction. No conclusion can be made about the intracellular location of the enzymes because of their rapid release into the solvent. The physiological interpretation of these findings is discussed.
The Loss of Certain Cellular Components from Human Erythrocytes during Hypotonic Hemolysis in the Presence of Dextran
Authors: Hjelm Magnus , ÖStling S. Goran , Persson A. Erik G.
Published: December 2008

The escape of certain cellular components (catalase, glucose‐6‐phosphate dehydrogenase, hexokinase, lactate dehydrogenase, adenosine‐triphosphate, glutathione) was studied in human red cells suspended in a hemolytic hypotonic salt solution containing dextran. There was in inverse relationship between size of a component and the relative amount of it escaping from the cell.
Dextran‐Induced Release of 5‐Hydroxytryptamine from Rabbit Platelets
Authors: Westerholm Barbro
Published: December 2008

The 5‐hydroxytryptamine (5‐HT)‐releasing activity of certain dextran fractions on rabbit platelets was investigated. Dextrans with the following average molecular weights (M̄w) were found to cause the release of 5‐HT: 42,000, 74,500, 141,000 (Dextran 150) and 267,000. No release was observed following the use of dextrans with average molecular weights of 22,700, 370,000 and 2,000,000. Release by Dextran 150 was found to require the presence of plasma and showed a distinct temperature optimum around 37°C. Heating the platelets to 47°C or the plasma to 56°C produced an irreversible inhibition of such release. Heparin, EDTA, and the enzyme blocking agents ninhydrin (NH2 group inhibitor) and allirin (SH‐group inhibitor) inhibited release. The results indicate that the release of 5‐HT from rabbit platelets induced by Dextran 150 involves the activation of enzymatic processes similar to those involved in the release induced by antigen and glycogen.
Functional Localization in the Cerebellar Cortex Studied by Quantitative Determinations of Purkinje Cell RNA: I. RNA changes in rat cerebellar Purkinje cells after proprio‐and exteroceptive and vestibular stimulation
Authors: Jarlstedt Jan
Published: December 2008

The effects of proprioceptive and exteroceptive stimulation and of vestibular stimulation on cerebellar Purkinje cell RNA content and composition were studied in male albino rats. After stimulation involving extero‐and proprioceptors a significant increase of RNA was found in the vermian part of the lobulus centralis, the pyramis, the copula pyramidis and the parafloculus. No such increase was found in the lateral parts of the lobulus centralis, lateral parts of the culmen, the simplex, crus I or in the nodulus. After vestibular stimulation an increase of RNA content occurred in the lobulus centralis and the nodulus but not in the pyramis, the copula pyramidis or in the paraflocculus. A significant decrease of the purine/pyrimidine quotient was found in the vermian part of the lobulus centralis and in the nodulus of rats receiving vestibular stimulation. A comparison between the neuroanatomical and electrophysiological findings in this field has been presented. The conclusions are drawn that Purkinje cells increase their RNA content upon stimulation and that this condition may be used for studies of functional localization in the cerebellum.
Studies on the Transport and Life‐Span of Amine Storage Granules in a Peripheral Adrenergic Neuron System1
Authors: Dahlström Annica , Häggendal Jan
Published: December 2008

The accumulation of noradrenaline (NA) above a ligation of the rat and cat sciatic nerve and the NA content of the adrenergic fibre system derived from this nerve were estimated. From the data obtained the rate of transport of amine storage granules and their life‐span were calculated. For the rat the rate of transport was found to be 5–6 mm per hr and the life‐span to be about 35 days. The corresponding values for the cat was 9–10 mm per hour and about 70 days, respectively.
Changes in Rat Pineal Stores of 5‐Hydroxytryptamine after Inhibition of its Synthesis or Break‐Down
Authors: Falgk B. , Owman Ch. , Rosengren E.
Published: December 2008

The formation and break‐down of 5‐HT in the rat pineal gland during daylight conditions has been investigated with a combination of fluorescence microscopic and fluorimetric methods. 5‐HT occurs in large and equal amounts in the pinealocytes and in the intrapineal sympathetic nerve fibres. Inhibition of 5‐HT synthesis either at the hydroxylation or at the decarboxylation step causes parenchymal 5‐HT to disappear within one to two hours, while little change is found in the nervous indole level. This indicates a turn‐over rate for 5‐HT in the pinealocytes considerably higher than in the intrapineal nerves. An intact sympathetic innervation of the pinealocytes is not essential for the 5‐HT turn‐over. Although monoamine oxidase is active in the degradation of pineal 5‐HT, inhibition of the enzyme does not increase pineal 5‐HT levels overtly, nor does it interfere with the turnover rate in the pinealocytes. Various explanations for this are offered.
Uptake of Metaraminol by the Adrenal Medullary Granules
Authors: Lundborg Per
Published: December 2008

Metaraminol is taken up by the adrenal medullary granules in vitro by displacing the endogenous catecholamines from their storage sites. This uptake is not blocked by reserpine. Metaraminol inhibits the ATP‐Mg++ ‐dependent uptake of adrenaline but does not utilize this mechanism for uptake. There thus seem to exist two uptake mechanisms in the amine granules, i.e. one ATP‐ Mg++‐dependent mechanism sensitive to reserpine, and the other acting by displacement of endogenous amines. Dopamine is capable of utilizing both, and metaraminol only the latter mechanism.
A Versatile Device for Microscopic Spectrofluorometry
Authors: Thieme Georg
Published: December 2008

To facilitate a close study of nerve varicosities, cell fractions etc. by means of histochemical fluorescence techniques, an inexpensive microspectrofluorometer has been constructed. A fluorescence microscope with a strong light source is combined with a sensitive photometer and two motor‐driven grating monochromators. The equipment allows recording of excitation, emission and absorption spectra from areas about 1 μ in diameter.
Surface Properties of Lung Extracts
Authors: Adams Forrest H. , Enhörning Göran
Published: December 2008

The importance of surface properties in the layer lining the alveoli is now well established. For measuring these properties a dynamic model of the alveolus has been constructed. It has the following advantages over previous techniques used to study the surface tension of biological fluids including lung extracts:

It more closely simulates the physiologic changes in rate and area that occur in the lungs during respiration.

Only a small volume of fluid (0.2 ml) is required.

The surface tension can be determined in 30 min or less.

It is suggested that the Viscoelastic properties of the alveolar surface film may be important as well as the surface tension in determining the response to compression and expansion.
Body Protein and Fat, Blood Glucose and Free Fatty Acids in Various Strains of Mice
Authors: Larsson Stig
Published: December 2008

Carcass composition was determined in the NMRI, CBA, Swisse and DBA strains, and in NMRI X Swisse made obese by injection of goldthioglucose. Fasting for 24 hrs resulted in different degrees of weight loss depending on the strain. At the same time analysis of carcass composition revealed strain differences with regard to protein and fat. The changes of glucose and FFA in plasma after 24 hrs without food also varied among the strains.
Cardiovascular Effects of Acute and Chronic Stimulations of the Hypothalamic Defence Area in the Rat
Authors: Folkow B. , Rubinstein E. H.
Published: December 2008

In experiments on rats long‐term intermittent stimulations of the hypothalamic defence area have been performed after that the characteristic responses to such stimulations had been explored in acute experiments. Weak topical stimulations of the defence area in rats induced an alerting response which was regularly accompanied by blood pressure and heart rate increases, increased muscle blood flow and decreased renal and gastrointestinal blood flows. When such weak intermittent stimulations of the hypothalamic defence area were continued for 12 hours daily during about four months the ‘resting’ blood pressure of a stimulated group of rats gradually rose, to become significantly different from that of a control group, which had been identically treated in all respects with exception of the intermittent hypothalamic stimulations. On the basis of these results it is discussed whether episodes of mental stress, which are often repeated during prolonged periods of time and which normally seem to excite the hypothalamic defence area, may act as an efficient “trigger” mechanism for gradually inducing a stage of chronic hypertension.
Some Properties of the Thalamic Relay Cells in the Spino‐Cervico‐Lemniscal Path
Authors: Andersen P. , Andersson S. A. , Landgren S.
Published: December 2008

Cells in nucleus ventralis posterolateralis thalami, lateral to the relay cells of the hindlimb component of the dorsal column pathway, have been studied with extra‐and intracellular recordings in cats anaesthetized with pentobarbital sodium. The cells in this part of thalamus are characterized by a considerable convergence, many cells being excited from the hindlimb component of the spinocervico‐lemniscal (SCLT) and the dorsal column (DC) pathways as well as from forelimb nerves. The synaptic action of an afferent volley was strong, and large unitary EPSPs were frequently observed, particularly when the SCLT was stimulated. Many of the cells were relay cells and could be antidromically invaded from the ipsilateral cortical areas S I and S II. A number of cells were antidromically invaded from both S I and S II, indicating that these cells project to cortex with a divided axon. Many cells showed an inhibition of the recurrent type.
Effect of Cholecystokinin on Small Intestine
Authors: Hedner Pavo , Person Henry , Rorsman Gunne
Published: December 2008

The effect of highly purified cholecystokinin on gall‐bladder and intestine was investigated in vivo and in vitro. The following results were obtained: The contraction of small intestine elicited b! cholecystokinin preparations is due to the hormone itself and not to impurities in the preparations; this intestinal effect of cholecystokinin is mediated by another mechanism of action than the effect of the hormone on the gall‐bladder; cholecystokinin in low concentrations seems to have a specific effect on the proximal part of the intestine. It is possible that the hormone may play a role in the regulation of intestinal motility.
Isolation of a Mast Cell Degranulating Polypeptide from Ascaris suis
Authors: Uvnäs B. , Wold J. K.
Published: December 2008

Ascaris suis was extracted with 60% ethanolin dilute formic acid after previous removal of fat with organic solvents. After dialysis, the extract was further purified by ammonium sulphate precipitation, treatment with Amberlite IRC‐50 (XE‐64), chromatography on CM‐ cellulose and gel filtration on Sephadex G‐25. The purified product with a molecular weight probably within the range 2000–3000, had basic character with an isoelectric point ca 12.3 in 0.05 M borate buffer. It behaved as a nearly homogeneous compound on paper electrophoresis and on gel filtration. Nitrogen content: 16.7%. Fifteen amino acids were identified by paper chromatography after acid hydrolysis: alanine, arginine, cystine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine and valine. The purified product was degradrd and inactivated by the proteolytic enzymes papain, pronase, trypsin, α‐chymotrypsin and partially by pepsin. The polypeptide caused degranulation of rat mesentery mast cells, even such cells from germ free animals, indicating that the mast cell respome was the result of a direct action of the Ascaris principle on the mast cell and not due to an antigen antibody reaction.
Spread of Excitation in the Smooth Muscle of the Rat Portal Vein
Authors: Johansson Börje , Ljung Bengt
Published: December 2008

The longitudinal musculature of the rat portal vein is characterized by spontancous, rhythmic contractions indicating effective intercellular conduction in this vascular smooth muscle. The present study was done in order to evaluate the relative importance of neurogenic and myogrnic mechanisms for the spread of excitation in an isolated preparation of this vessel. A local anesthetic agent, in concentrations which blocked impulse transmission in autonomic nerves, failed to interfere with conduction in the smooth muscle of the portal vein whereas hyperosmolarity. which is considered to preclude electro tonic spread of action potentials between muscle cells (Barr. Dewey and Rerger 1965), caused desynchronization of the contractile activity. It is concluded that conduction in this vascular smooth muscle is myogenic in nature. The fact that the portal vein, in contrast to most other vessels, is equipped with a “double plexus” of adrenergic nerve fibres (Fuxe. personal communication) does not seem to be important for coordination of its spontaneous contractions. The influence of the hyperosmotic environment on the electrical and mechanical activity of the portal vein is illustrated by experiments with a sucrose‐gap technique. The mode of action of hyperosmotic solutions is discussed.
The Effect of DOPA on the Spinal Cord 5. Reciprocal organization of pathways transmitting excitatory action to alpha motoneurones of flexors and extensors
Authors: Jankowska E. , Jukes M. G. M. , Lund S. , Lundberg A.
Published: December 2008

In unanaesthetized spinal cats, injected with L‐DOPA, volleys in the flexor reflex afferents (FRA) evoke a long‐latency, longlasting discharge in ipsilateral flexor and contralateral extensor motoneurones. It is postulated that this discharge is transmitted by a neuronal pathway which is inhibited in the normal acute spinal cat, presumably from the pathway, which in this state transmits the shortlatency effect from the FRA to motoneurones. The organization of the pathway released by an injection of DOPA has been analyzed by recording the discharges in efferents to flexors and extensors and with intracellular records from motoneurones. Combined stimulation of ipsilateral and contralateral FRA reveals a reciprocal organization in that either flexor or extensor motoneurones are activated. Transmission from the ipsilateral FRA to flexor motoneurones can be inhibited by volleys in the contralateral FRA, and transmissiqn from the contralateral FRA to extensor motoneurones by volleys in the ipsilateral FRA. These inhibitory effects are neither produced postsynaptically in the motoneurones nor presynaptically by depolarization of primary afferents and are hence exerted at an interneuronal level. The organization of reciprocal innervation at an interneuronal level is discussed in relation to the primary afferent depolarization evoked in Ia afferent terminals after DOPA and to rhythmic alternating movements.
Uptake and Release of u‐Methyl‐Noradrenaline in Vitro after Reserpine Pretreatment A Histochemical Study
Authors: Hamberger Bertil , Malmfors Torbjörn
Published: December 2008

The reserpine‐rcsistent uptake and storage of α‐methyl‐noradrenaline in vitro were investigated in thr adrenergic nerves of the rat iris. After reserpine pretreatment, an effective accumulation of α‐methyl‐noradrenaline took place intraneuronally. The amine remained intraneuronally for several hours ivhen incubated in amine‐free medium at 37°C. The morphological appearancc changed during the incubation in a manner suggesting that part of the amine was bound to an intraneuronal structure, which might be the amine storage granules. Interference with energy generation in the ˜ncdiurn, as well as chemical depolarization by increasing potassium ion concentration in the inediuin, inhibited accumulation and caused a rapid release of α‐methyl‐noradrenaline. Protriptyline inhibited the uptake of α‐methyl‐noradrenaline efficiently, and also enhanced the disappearance of accumulated amine. Although (+)‐amphetamine was less potent in preventing uptake. it produced a rapid rclease of the amine.
The Role of Gastric Mucosal Mast Cells during Triton WR‐1349 Lipemia of Rats
Authors: Haikonen Matti , Räsänen Toimi , Taskinen Eero
Published: December 2008

Rats were intraperitoneally injected with 1 × 50 mg and 3 × 50 mg of Triton WR‐1339. There occurred steep increase in esterified fatty acids and cholesterol, and the plasma proteins decreased. The mucosal mast cell count and the metachromatic granulation of these cells increased, after a primary decline, in the gastric and jejunal walls under the effect of Triton. The bearing of the phenomenon on hyperlipaemia is considered in the discussion, bringing up the potential inhibition of heparin release.
The Effects of Hypercapnia and Hypoxia on the Distribution of Capillary Blood Flow in the Denervated Intestinal Vascular Bed
Authors: Svanvik Joar , Tyllström Jöran , Wallentin Ingemar
Published: December 2008

Experiments are described which demonstrate that both hypercapnia and hypoxia exert a potent relaxing influence on the resistance vessels of the denervated intestine. The effects on the capillary fluid exchange capacity, as indicated by the capillary filtration coefficient (CFC), are, however, more complex. During local hypoxia CFC increases considerably, probably reflecting a direct relaxing influence on the precapillary sphincter section. In contrast, during hypercapnia CFC decreases in spite of an augmented blood flow. This is assumed mainly to be due to an increased myogenic activity in the same sphincter section, elicited locally by a raised transmural pressure and blood flow. Functional implications of the results are briefly discussed. They suggest that neither high Pco2 accompanied by a low pH, nor low Po2 are of major importance for a functional intestinal hyperemia during digestion.
The Effect of Some Neutral Macromolecules on the Pattern of Hypotonic Hemolysis
Authors: Davies Howard G. , Marsden N. V. B. , ÖStling S. Göran , Zade‐Oppen A. M. M.
Published: December 2008

Three neutral polymers, ficoll, dextran and polyethyleneglycol, all inhibit hemoglobin liberation in hypotonic electrolyte solutions. If red cells are suspended in a hypotonic solution which, in the absence of a polymer, would hemolyse all the cells, only a part of the hemoglobin is liberated. The polymer does not alter the fragility but only the amount of hemoglobin liberated from the individual cells. The inhibitory effect is proportional to the weight concentration of the polymer and independent of the mol. wt. within wide limits. The inhibitor molecules must presumably have a critical minimal size since the trisaccharide raffinose did not inhibit hemoglobin liberation under similar conditions. From the data on the lowest molecular weight dextran fraction it was concluded that the lower limit for dextran was below a molecular weight of about 1700. Complete inhibition of hemoglobin liberation was never obtained and from the evidence available it is suggested that the first 20 per cent, at least, of the hemoglobin may escape with a bulk outflow. The colloid osmotic relationships of the cell during and after hemolysis are discussed and it is concluded that cannot be decided whether the polymer effect is colloid osmotic in nature.
Intracellular Distribution of Lipolytic Enzymes in the Rat Pancreas
Authors: Arnesjö Bo , Filipek‐Wender Helena
Published: December 2008

Intracellular distribution of lipase (glycerolester hydrolase EC 3.1.1.3.), cholesterol esterase (sterol ester hydrolase EC 3.1.1.13.), phospholipase (EC 3.1.1.4.) and of carboxylic ester hydro‐lases (EC 3.1.1.1.) has been studied using isopycnic gradient centrifugation of rat pancreatic homogenates. The identity of the fractions obtained has been established using phase contrast and electron microscopy. Zymogen granules equilibrated at a mean density of 1.224 in aqueous sucrose gradients, mitochondria and cytomembranes at a mean density of 1.19 and 1.16–1.14, respectively. The zymogen fraction accounted for 25–45 % of the total activities of lipase, cholesterol esterase and phospholiphase. The specific activities (activity per mg protein) in the zymogen fraction were 5–7 times higher than those of the other cell fractions. A bile salt stimulated carboxylic ester hydrolase was found concentrated to the zymogen granules. The membrane and cell sap fractions accounted for almost all of the remaining lipolytic enzyme activities.
Changes in Dynamic Sensitivity of Primary Endings of Muscle Spindle Afferents Induced by DOPA
Authors: Bergmans J. , Grillner S.
Published: December 2008

In the spinal unanesthetized cat, muscle spindle afferents from primary endings originating in the tenuissimus muscle were studied during a ramp stretch to the muscle with intact efferent nerve supply before and after an intravenous injection of DOPA. It was demonstrated that the peak and mean frequency during stretch was decreased after DOPA, when there also occurred firing during release of stretch. The results indicate that there is after DOPA a decreased spontaneous activity in dynamic y‐motoneurones and a concomitant increase in static fusi‐motor activity. The findings support the idea that descending noradrenergic fibres control, in a reciprocal fashion, the spontaneous activity in static and dynamic y‐motoneurones to flexors.
Role of Uptake and Oxidation of Plasma Free Fatty Acids by the Liver in the Development of the Ethanol‐Induced Fatty Liver
Authors: Fex Göran , Olivecrona Thomas
Published: December 2008

Groups of fasted female rats were tube fed ethanol (6 g/kg b.w.), an isocaloric amount of glucose, or nothing. Half of the rats in each group were given hourly s.c. injections of nicotinic acid. 6 hrs after the feeding, 9–10‐H3 oleic acid complexed to serum albumin was injected intravenously. 5 min later the rats were killed and concentrations of plasma free fatty acids and of liver glycerides and labeling of liver and carcass lipids was determined.

Plasma free fatty acid concentrations were similar in the ethanol fed and the fasted rats but lower in the glucose fed rats. In all groups nicotinic acid lowered plasma free fatty acid concentration.

Liver glyceride concentration was elevated in the ethanol fed rats. In all groups nicotinic acid lowered the liver glyceride concentration.

Total liver radioactivity was highest in the ethanol fed rats, intermediary in the glucose fed rats and lowest in the fasted rats. The liver radioactivity was not significantly changed by nicotinic acid. It is suggested that the differences in liver radioactivity between the groups reflects differences in the oxidation of plasma free fatty acids taken up by the liver and that a major cause of the ethanol induced fatty liver is a decreased hepatic oxidation of plasma free fatty acids taken up at a normal rate.
Possible Functional Differentiation between the Stores from which Adrenergic Nerve Stimulation, Tyramine and Amphetamine Release Noradrenaline
Authors: Obianwu Hopé O.
Published: December 2008

Effects of inhibition of monoamine oxidase and tyrosine hydroxylase on the contraction of rat lower eyelid and pressor response to tyramine, amphetamine and adrenergic nerve stimulation have been studied. Inhibition of MAO markedly enhanced both the peak and the duration of response of the eyelid to tyramine and amphetamine while only moderately augmenting the durations of pressor response to tyramine. Contraction of the eyelid to nerve stimulation was not affected.

Inhibition of tyrosine hydroxylase abolished the contraction of the eyelid to amphetamine while only slightly reducing that to tyramine. The contraction of the eyelid to nerve stimulation was not affected.

The results suggest that nerve stimulation, tyramine and amphetamine release noradrenaline from different stores. The nature of these stores is discussed.
Intracellular Distribution of Lipase in Comparison to Trypsinogen, Amylase and Immediately Measureable Trypsin Inhibitor(s) in the Rat Pancreas
Authors: Arnesjö Bo , Grubb Anders
Published: December 2008

The intracellular distribution of lipase (glycerol ester hydrolase EC 3.1.1.3.), trypsinogen (EC 3.4.4.4.), amylase (EC 3.2.1.1.) and immediately measurable trypsin inhibitor(s) has been studied using isopycnic gradient centrifugation of rat pancreatic homogenates. A modified method for the measurement of trypsinogen is presented and a micromethod for the estimation of trypsin inhibitory activity is described. By comparison with lipase smaller proportions of the total trypsinogen and amylase activities were recovered from the zymogen fractions. The total immediately measurable trypsin inhibitory activity was mainly localised in the cytomembrane fractions, while virtually no activity was found in the zymogen granules. The specific activity (activity per mg protein) for both amylase and trypsinogen was high in the zymogen and in the cell sap fractions. For lipase and immediately measurable trypsin inhibitory activity, however, the specific activity was high only in the zymogen granules and cytomembranes, respectively.
Ventilation Hypoxia and Pulmonary Vascular Resistance Effects of Changes in Plasma Potassium Concentration
Authors: Hauge Anton
Published: December 2008

The effects of stepwise rises in plasma potassium concentration on the pressor responses to short (less than 3 min) periods of ventilation hypoxia and to vasoconstrictor agents, were investigated in isolated blood‐perfused rat lungs. Both hypoxia‐responses and drug‐responses were potentiated. Plasma potassium ion concentrations above 17.0 to 18.8 meq/l caused dose‐dependent sustained elevations of pulmonary vascular resistance (PVR). Ventilation hypoxia superimposed on such high PVR did still cause brisk pressor responses. Potassium‐induced vasoconstriction were obtained also in periods with no pressor responses to ventilation hypoxia i.e. by cooling of the perfusate or late in a perfusion. The results suggest that a reduction of the vascular smooth muscle cell ratio [K+]i/[K+]0 by hypoxia‐induced transcellular leakage of potassium‐ions is not the sole mechanism for the pressor response to acute ventilation hypoxia.
Effects of Increased Intracranial Pressure on Cerebral Blood Flow and on Cerebral Venous pO2, pCO2, pH, Lactate and Pyruvate in Dogs
Authors: Kjällquist Å. , Siesjö B. K. , Zwetnow N.
Published: December 2008

The effects of increased cerebrospinal fluid (CSF) pressure on cerebral blood flow and on cerebral venous pO2, pCO2, pH, lactate, and pyruvate were studied in dogs by infusing an artificial CSF into the cisterna magna. With moderate and rapid increases in the CSF pressure, which did not lower cerebral perfusion pressure below 60–70 mm Hg, the cerebral blood flow was not measurably lowered, although there were sometimes detectable metabolic changes in cerebral venous blood suggestive of a transient reduction of the cerebral blood flow. That is, cerebral venous pO2 and pH decreased slightly, and there were increases in the cerebral venous pCO2, in the lactate and pyruvate concentrations, and in the lactate/ pyruvate ratios, indicating an anaerobic glucolysis. When the pressure was released there was usually no reactive hyperemia, and no persisting metabolic changes in the cerebral venous blood. When the CSF pressure was markedly increased, and the cerebral perfusion pressure accordingly reduced to 30–50 mm Hg there were marked metabolic changes in cerebral venous blood, the pO2 often approaching 10 mm Hg. In this case, a sudden reduction of the CSF pressure was almost invariably followed by a significant reactive hyperemia, which was paralleled by an arterialization of cerebral venous blood with a high pO2 and a low pCO2. The changes in pO2 usually expressed the changes in flow. During and after the reactive hyperemia there were no lactate/pyruvate changes to indicate the preceding period of anaerobic glucolysis.
Studies of Blood‐pressure Regulation
Authors: ÖBerg P. Å. , Sjöstrand U.
Published: December 2008

A method has been worked out by which one of the closed control circuits in the blood‐pressure‐regulating system of the dog can be reversibly opened and closed again with the aid of an on‐line analog computer. This makes it possible to study the regulatory properties of the carotid‐sinus reflex, as regards the baroreceptor function, in the regulation of the systemic blood pressure. Proportional characteristics in the analog produce marked instability in the blood‐pressure regulation, while with increasing proportional‐plus‐derivative characteristics the stability is increased. The electronic analog can be given characteristics that produce the same step‐function response in the systemic pressure as the biological reflex.
The Influence of Arterial PO2 on Renal Tissue PO2
Authors: Aperia Anita C.
Published: December 2008

When arterial PO2 is increased to supra‐atmospheric tensions approximating 500 mm Hg in the dog, the PO2 of the renal cortex rises from under 50 mm Hg to the range of 130 mm Hg, in contrast with that of the outer medulla which may even fall; there is little absolute change in the already extremely low PO2 of the inner medulla. These observations are interpreted to support the idea of a homeostatic mechanism operating to regulate medullary blood flow as already suggested by observations of urine PO2 at various arterial O2 tensions. This mechanism helps to maintain the hypoxic state of the medulla appropriate to its relatively anaeroboic metabolism.
Neurogenic Adjustments of Muscle Blood Flow, Cutaneous A‐V Shunt Flow and of Venous Tone during “Diving” in Ducks
Authors: Djojosugito A. M. , Folkow B. , Yonce L. R.
Published: December 2008

The effect of “diving” on the vascular response in skeletal muscle, the web and the veins was studied in experiments on ducks. Muscle blood flow completely stopped during submersion due to neurogenic vasoconstriction of the resistance vessels, at the same time as the constrictor fibres to the systemic veins were excited. As a contrast, web blood flow changed only little during submersion, unless the duck was excited. In this latter case it decreased, whether the animal was submerged or not. The profound muscle vasoconstriction helps to conserve the oxygen stores for the “essential” tissues, the heart and the brain. The preserved web blood flow, on the other hand, primarily passes through A‐V shunts and, in conjunction with the venous constriction, it pushes blood from the considerable, oxygen‐containing venous depots to the heart without causing peripheral oxygen “losses” from the blood. Such mechanisms serve to make the total venous oxygen stores available for subsequent cardiac output to the brain and the myocardium.
Adrenergic Neuron Blockers and Transmitter Release after Sympathetic Denervation Studied in the Conscious Rat
Authors: Lundberg Dag
Published: December 2008

13 to 15 hrs after excision of the superior cervical ganglion the postdenervation ptosis in the rat is reversed for about 12 hrs due to release of transmitter from degenerating nerve terminals. This degeneration contraction has been studied in unanesthetized rats. A special apparatus with an image splitting eyepiece was constructed for the measurement of the palpebral aperture at a distance. The time course of the degeneration contraction was found to correlate well with that of postdenervation transmitter depletion earlier found by other workers using biochemical and histochemical methods. Earlier findings that postdenervation depletion is delayed by bretylium were fully confirmed. It was also found that the neuron‐blockers beta‐TM 10 (10–50 mg/kg), bethanidine (10–50 mg/kg) and BW 392C60 (10–75 mg/kg) caused much less delay than bretylium at 1 to 50 mg/kg. The delayed degeneration contraction has a normal appearance and magnitude. There is no correlation between the neurone blocking action of the drugs and their “delaying effect”.
Electrical Stimulation of a Human Ventrolateral‐Subventrolateral Thalamic Target Area
Authors: Johansson Gunnar G.
Published: December 2008

A ventrolateral‐subventrolateral thalamic target area was electrically stimulated in connection with stereotaxic neurosurgery in 20 alert patients with Parkinson's disease, in 5 patients with hereditary intention tremor and in 1 patient with an atypical congenital tremor. The purpose of the investigation was to study whether an altered pulse duration had any effect on the projected clinical responses evoked by the stimulation. Unidirectional square wave pulses with durations ranging from 0.1 to 25 msec and a repetition frequency of 1 pulse per second were therefore applied. The stimulation threshold for clinical responses was maintained by balancing every pulse duration tested with the peak current. The responses consisted mainly of muscular jerks or twitches projected to various contralateral parts of the body. The localization of the threshold responses depended on the pulse duration used. The motor character of the responses remained unchanged with all pulse durations tested. The peak current‐pulse duration relationship for the threshold responses was studied. The results are discussed.
A Cyclic Variation in the Exfoliation of Cells from the Urethra of the Male Mouse
Authors: Jäurnebrand K. , Kihlströum J. E.
Published: December 2008

Five different types of exfoliated cells, representing different stages of cornification, have been observed in daily urethral smears from male mice. The frequencies of the cells belonging to two of these types vary cyclically. The mean duration of the cycles is about 3.5 days.