bluuebunny/crossref_metadata_2025 huggingface dataset:
Intestinal Dipeptidases. Development of Dipeptidase Activity in the Small Intestine of the Rat as Related to the Development of the Intestinal Mucosa
Authors: Lindberg Tor , Owman Christer
Published: December 2008

The development of five intestinal dipeptidase activities (L‐alanyl‐L‐glutamic acid, L‐alanyl‐L‐proline, glycylglycine, glycyl‐L‐leucine and glycyl‐L‐valine dipeptidase activity) in the rat from 15 days post coitum up to 3 weeks post partum was investigated and related to the structural development of the rat small intestinal mucosa. Very low enzyme activities were found in the period of mucosal cell proliferation (15 to 18 days post coitum). At 18 1/2 days post coitum the period of mucosal cell differentiation was commencing, and simultaneously the dipeptidase activities began increasing to reach maximal values at parturition, by which time the differentiation was finishing. Within a few hours of birth, when the newborns had suckled, an abrupt and significant fall to the relatively low adult level was observed for four of the dipeptidase activities. The fifth enzyme activity (L‐alanyl‐L‐proline dipeptidase) declined more slowly postnatally and first reached the relatively low adult level during the 3rd week post partum. The relation of the changes in the intestinal dipeptidase activities to the structural characteristics of the mucosa during the development has been discussed.
Catecholamine Excretion in Adreno‐Demedullated Rats Exposed to Gold after Chronic Guanethidine Treatment
Authors: Pouliot M.
Published: December 2008

Adreno‐demedullated rats subjected to a moderate cold exposure showed a significant increase in urinary excretion of noradrenaline (NA) and maintained their thermal equilibrium. Adrenodemedullated rats, chronically pretreated with guanethidine, however, failed to respond with an increase in NA excretion upon exposure to 3° C and all the animals died 7 days later following a fall in urinary NA. These results suggest that the survival of cold stressed adreno‐demedullated animals is dependent upon a peripheral secretion of NA.
Studies on the Ganglionic Site of Action of Sympathetic Outflow to the Stomach
Authors: Jansson G. , Martinson J.
Published: December 2008

In acute experiments on cats anesthetized with chloralose, inhibition of excitatory vagal responses of gastric smooth muscle was produced by reflex or direct activation of an adrenergic nerve fibre system. The reflex that could be elicited by distension of a jejunal loop or stimulation of mesenteric afferents was dependent on intact spinal connections because it was blocked by spinal anesthesia. Activation of the adrenergic nerve fibre system did not inhibit gastric myogenic tone or gastric muscle contraction elicited by the muscarinic action of acetylcholine. It was therefore concluded that the adrenergic outflow responsible for this type of inhibition acts on parasympathetic intramural ganglion cells involved in the excitatory control of gastric motility.
Uptake, Storage and Release of Histamine by Rat Peritoneal Mast Cells in vitro
Authors: Cabut Martha , Haegermark ÖSten
Published: December 2008

Rat peritoneal mast cells, when incubated in histamine‐H3containing medium, were shown to take up and concentrate histamine. The uptake was proportional to incubation time and to extracellular histamine concentration. Metabolic inhibitors did not significantly affect the uptake. The exogenous histamine was bound to mast cell granules in about the same proportion as found for the endogenous. Treatment of mast cells with compound 48/80 released the same relative amounts of both exogenous and endogenous histamine. These results suggest that histamine was taken up by passive diffusion and stored in the mast cell granules. High concentrations of 5‐HT inhibited the histamine uptake, whereas histidine and 5‐HTP did not influence the process.
Effect of Ethionine on the Absorption of Palmitic Acid‐1‐C14in the Rat
Authors: Karvinen Esko , Miettinen Matti
Published: December 2008

Ethionine administration to female rats resulted in significantly lower rate of absorption of ingested palmitic acid‐1‐C14as compared with that of saline‐treated controls.
Chloride and Hydrogen Ion Distribution between Human Red Cells and Plasma
Authors: Funder Jørgen , Wieth Jens Otto
Published: December 2008

Distribution of Cl‐and H+between human red cells and plasma has been studied after variations of plasma pH (induced both by changing pCO2 and changing bicarbonate concentration). The distribution ratio of chloride Cl‐cell/Cl‐plasma = r(Cl‐), and of hydrogen ions H+plasma/H+cell = r[H+], showed the following relations to plasma pH:

r(Cl‐) = 3.319—(0.359 pHplasma)

r[H+] = 3.094—(0.335 pHplasma)

The conception that the distribution of Cl‐and H+is a Donnan distribution, is supported by the distribution of Cl‐and H+found after addition of an impermeant, negatively charged ion (citrate) to the extracellular phase. The normally negative potential difference between cells and plasma may be inverted in the presence of citrate. The effects on ion distribution seen, when normal cells are suspended in isotonic sucrose or glucose, can be explained as being caused by diffusion potentials, which arise because of the much higher permeability of the red cell membrane towards anions than towards cations. Calculation of the water shift to be expected as the osmotic consequence of the redistribution of diffusible anions between cells and plasma (—ΔH2O/ΔpH: 423g H2O/kg RBC solids) was found to agree with the experimentally determined value of 404g H2O/kg RBC solids.
Inhibitory Action of Adrenergic Blocking Agents on Catecholamine Release and Uptake in Isolated Nerve Granules
Authors: Euler U. S. Von , Lishajko F.
Published: December 2008

A series of adrenergic α‐and β‐blockers have been found to decrease the release rate of nor‐adrenaline from a suspension of bovine splenic nerve granules incubated in phosphate buffer at pH 7.5. The same blockers also inhibited the uptake of noradrenaline in partially depleted nerve granules in the presence of ATP—Mg++. It is tentatively suggested that the interactions of the adrenergic blocking agents with uptake mechanisms for noradrenaline in the nerve granules and at the receptor level in effector cells involve certain common features.
Effect of Finnish Bath (Sauna) on the Urinary Excretion of Noradrenaline, Adrenaline and 3‐Methoxy‐4‐Hydroxy‐Mandelic Acid
Authors: Huikko M. , Jouppila P. , Kärki N. T.
Published: December 2008

For the present work the urinary excretion of noradrenaline, adrenaline and 3‐methoxy‐4‐hydroxymandelic acid in 18 healthy young persons during a sauna bath were studied. The average basal excretion of noradrenaline was 30.6 ± 3.4ng/min, and due to the influence of sauna it rose to 46.6 ± 4.1ng/min. Average adrenaline excretion during basal activity was 7.0 ± 0.7ng/min, and in the sauna 9.6 ± 1.1ng/min, while the figures for excretion of 3‐methoxy‐4‐hydroxy‐mandelic acid were 4.2 ± 0.3μg/min and 4.6 ± 0.4μg/min.
The Effect of DOPA on the Spinal Cord 3. Depolarization Evoked in the Central Terminals of Ipsilateral Ia Afferents by Volleys in the Flexor Reflex Afferents
Authors: Andén N.‐E. , Jukes M. G. M. , Lundberg A. , Vyklický L.
Published: December 2008

In unanaesthetized spinal cats, injected with 1‐DOPA, volleys in the flexor reflex afferents (FRA) evoke a long latency, long lasting dorsal root potential (DRP). Measurements of excitability of ispilateral primary afferent terminals show a corresponding depolarization of Ia, but not Ib or cutaneous, afferent terminals. Volleys in the FRA have no effect on Ia afferent terminals in the normal acute spinal cat, presumably because the neuronal pathway transmitting the effect from the FRA to Ia afferents is inhibited by activity in another pathway from the FRA. Results are presented showing that after intravenous injection of DOPA volleys in the FRA can inhibit transmission from the FRA to Ia afferents. It is suggested that this inhibitory effect from the FRA also is responsible for the hyperpolarization of Ia afferent terminals that sometimes is evoked from the FRA after DOPA and is probably caused by a removal of depolarization.
The Effect of DOPA on the Spinal Cord 4. Depolarization Evoked in the Central Terminals of Contralateral Ia Afferent Terminals by Volleys in the Flexor Reflex Aflerents
Authors: Jankowska E. , Lund S. , Lundberg A.
Published: December 2008

After injection of DOPA in unanaesthetized spinal cats volleys in the flexor reflex afferents (FRA) evoke a late long lasting Contralateral dorsal root potential. Measurements of excitability of contralateral afferent terminals show a corresponding depolarization of Ia, but not of Ib or cutaneous afferent terminals. Results are also presented showing that transmission from the FRA to contralateral Ia afferent terminals can be inhibited from the FRA.
Length at Inactivated Contractile Elements, Length‐tension Diagram Active State and Tone of Vascular Smooth Muscle
Authors: Lundholm Lennart , Mohme‐Lundholm Ella
Published: December 2008

Analysis of the mechanical properties of vascular muscle is complicated by the fact that normally it is contracted to a certain degree and has no constant resting length. By total blockade of the energy production of the muscle with monoiodoacetic acid under anaerobic conditions the vessel length at inactivated contractile elements could be measured. With the aid of this length the length‐tension diagram of the vascular muscle in untreated and adrenaline‐treated vessels was studied. The muscle developed a maximal tension (2.100gwt/cm2 cross section) at this length, which therefore probably corresponded to L0 in skeletal muscle. The vascular muscle shortened maximally to 25 per cent of the relaxed length. Both the development of maximal isometric tension and the maximal isotonic shortening were of the same magnitude in vascular as in skeletal muscle. The series‐elastic component (15–20 per cent) was, on the other hand, greater in vascular than in skeletal muscle. No rigor mortis was noted in the vascular muscle. The spontaneous tension of the vascular muscle and tension increase induced by adrenaline could be largely ascribed to an active state. The question of whether a “tonic” or “catch” mechanism is present in vascular muscle, independent of the active state, is discussed.
Cat Retinal Ganglion Cell Responses to Changing Light Intensities: Sinusoidal Modulation in the Time Domain
Authors: Cleland B. , Enroth‐Cugell Christina
Published: December 2008

Action potentials were recorded from single axons of retinal ganglion cells in adult lightly anesthetized, paralyzed cats (intact eye). A small, sinusoidally time modulated stimulus was located in the most responsive portion of the receptive field center. The mean discharge frequency was monitored on a counter during the experiment and the responses over extended periods of time were recorded on tape and later averaged. Most of the cells were outside area centralis. A series of experiments showed that doses of muscle paralyzing agents several times larger than those commonly used in cat retinal ganglion cell experiments were needed for unfailing long‐lasting eye immobilization. In a second series of experiments the mean discharge frequency of the cell, the peak‐peak amplitude of the averaged response and the stimulus‐response phase difference were studied as: (a) a function of modulation depth at constant frequency, (b) a function of stimulus frequency at constant depth of modulation. Only two of 31 cells exhibited (up to 40 per cent modulation) a mean discharge frequency independent of modulation depth, a response amplitude reasonably proportional to modulation depth, an almost constant stimulus‐response phase difference and an averaged response whose shape was almost sinusoidal. The remaining cells failed to fulfill at least one of these requirements for linearity. For 6 cells modulation sensitivity curves were determined and found to have the same general shape as those subjectively determined in humans.
Extraneuronal Binding of Catecholamines and 3,4‐Dihydroxyphenylalanine (dopa) in Salivary Glands
Authors: Hamberger Bertil , Norberg Karl‐Axel , Olson Lars
Published: December 2008

In vivoandin vitrostudies using the histochemical fluorescence technique of Falck and Hillarp were made on the submaxillary and sublingual glands of the rat after the administration of catecholamines or dopa, or the incubation of slices of the glands with the same drugs. Catecholamines and in all probability also L‐dopa were found to be bound extraneuronally in the salivary gland parenchyma under the conditions of the experiments. It is probable that the present experiments visualize the same type of extraneuronal binding as has been found with biochemical techniques. It appears that a certain activity of the parenchyma is necessary for the binding to occur. Apart from being a source of error in the evaluation of biochemical measurements, extraneuronal binding may be of importance related to transmitter mechanisms.
The Effect of Immunosympathectomy on the Retention and Metabolism of Noradrenaline
Authors: Sjöqvist Folke , Taylor Palmer W. , Titus Elwood
Published: December 2008

The retention of radioactive noradrenaline (NA) was measured in different organs of immunosympathectomized (I.S.) mice 30 min after i.v. injection of dl‐NA‐7–3H (17.9 or 1.79μg/kg, S.A. 4.7 C/mmole). A striking decrease in the capacity to retain NA‐3H was observed in the heart (1.6 per cent of controls) and the submaxillary gland (4.1 per cent of controls). Immunosympathectomy was only partially effective in the intestine and colon (33 and 47 per cent of normal retention, respectively). By contrast, the retention of NA in the I.S. vas deferens was almost doubled. These data support previous investigations indicating that immunosympathectomy has a differential effect on adrenergic neurons located in different organs. A chromatographic analysis of the distribution of3H among the various NA‐metabolites was undertaken in the submaxillary gland, heart and vas deferens. Metabolites, for the most part methylated, accounted for a larger precentage of the total3H in the extracts from tissues of I.S. animals compared to controls. In the I.S. submaxillary glands of both the mouse and the rat the radioactivity retained after injection occurred mostly in the form of metabolites. Normetanephrine (NM) was predominant in the mouse, while both NM and acid metabolites were significant components in the rat gland. Oxidation to acid metabolites was more extensive in the I.S. heart of the rat compared to the mouse. The chromatography of the retained metabolites in the I.S. vas deferens was not qualitatively different from that of the normal organ.
Incorporation in Vivo of Acetate‐1–14C into Liver and Serum Lipids in Hemorrhagic Lipemia in the Rat
Authors: Hirvisalo E.‐L. , Louhija Antti
Published: December 2008

Hemorrhagic anemia and lipemia was produced in 18 rats by daily bleedings of about 2 ml per 100 g of body weight during 6 days. Seventeen sham‐bled rats served as controls. In the bled rats the serum triglycerides increased to about twice their initial values during the experiment and a slight tendency of fat accumulation in the livers was observed. Radioacetate was injected i.p. on the 7th day of the experiment, and the recovery of the label in liver and serum total fatty acids and in triglyceride and phospholipid fractions, separated by thin layer chromatography, was estimated 45 min and 3 hrs after the injection. Significantly less radioacetate was incorporated into liver and serum total fatty acids in the bled rats than in the sham‐bled controls, but there were no remarkable differences between the bled and the sham‐bled groups in the relative distribution of the label in the triglyceride and phospholipid fractions of the liver and serum. This study, which is an extension of previous studies of the lipid metabolism in hemorrhagic lipemia, shows that an increased de novo synthesis of fats can probably be ruled out as a cause of hemorrhagic lipemia.
The Effect of High Pressure Air or Oxygen with and without Carbon Dioxide Added on the Catecholamine Levels of Rat Brain
Authors: Haggendal Jan
Published: December 2008

The noradrenaline and dopamine levels in brain have been studied biochemically after exposure of rats to pure oxygen, oxygen and carbon dioxide, air, air and carbon dioxide at increased pressure up to 6 to 7 ata. After exposure to air with or without carbon dioxide added the catecholamine levels were unchanged, except for a tendency to decreased levels after about 5 hrs exposure to air without carbon dioxide at 7 ata. The behaviour of the rats during the exposure was unchanged. After exposure to oxygen decreased noradrenaline levels were found. Also the dopamine levels seemed to be decreased, but with carbon dioxide added to the oxygen the dopamine levels appeared to increase. During the oxygen exposure most rats developed convulsions. The onset of the convulsive state appeared earlier in rats exposed to oxygen with carbon dioxide added.

The effects on the catecholamine levels are discussed with respect to e.g. the convulsions. Some symptoms at exposure to these gases at high pressure are suggested being due to effects on catecholamine or monoamine containing neurons in the brain.
The Transport of Noradrenaline Between two Simultaneously Performed Ligations of the Sciatic Nerves of Rat and Cat
Authors: Dahlström Anica
Published: December 2008

The behaviour of noradrenaline (NA) in double ligated rat and cat sciatic nerves was studied histo‐chemically, using the fluorescence method of Hillarp and coworkers, and biochemically using the trihydroxyindole method. It was found that a large amount of the NA in thc nerve betwcen the two ligations was transported down to the part just above the low ligation. By both method:; it was shown that during the first hours after the ligation the course of accumulation of NA in the nerve just proximal to the low ligation was about the same as the accumulation curve for the nerve (connected to the cell bodies) above the high ligature. Thereafter no further changes were found to occur in the nerve between the constrictions, whereas in the part above the high ligature the accumulation of NA continued as described earlier. The total NA content in the nerve between the two ligatures did not exceed the amount of a normal nerve of the same length. It was concluded that the transport mechanism in the adrenergic fibres is mainly independent of the cell hody (and the nerve terminals) and that no increase in the NA content in the axons occurs after a ligation of the nerve. Furthermore, the present study gives support to the earlier obtained data for the transport of amine granules in the sciatic nerve of rat and cat.
Carbon Dioxide Excretion and pH‐Variations in Diving Ducks after Carbonic Anhydrase Inhibition
Authors: Andersen Harald T. , Hustvedt Bo‐Egil
Published: December 2008

Acetazolamide (Diamox®), was administered intravenously to domestic ducks in doses of 10–100 mg/kg b.w. The smallest dose of acetazolamide required for maximal inhibition of blood carbonic anhydrase in the duck is approximately 50 mg/kg b.w. Inhibition of carbonic anhydrase produced no decrease in total‐CO2 of arterial plasma in the pre‐diving period despite acidosis and hyper‐ventilation (pH 7.25). Asphyxia with severe acidosis was induced in diving experiments of 6 min duration. Total‐CO2 in arterial plasma and pH in arterial blood were determined before, during and after the dive. Inhibition of carbonic anhydrase caused a reduced buffering capacity in the blood. This was particularly noticeable in the post‐diving period during which the arterial pH decreased to about 6.95 (normal value 7.10–7.15). The excretion of CO2 due to post‐diving hyperventilation reduced the arterial total‐CO2 from approximately 25 meq/l to approximately 15–20 meq/l whereas it normally falls to about 9–10 meqll upon emersion.
Effect of Circulatory Disturbance of the Testis on the Rectum‐Testis Temperature Difference in the Rat
Authors: Kormano Martti
Published: December 2008

Circulatory disturbance in the rat testis was produced by injecting 0.03 mmoles/kg cadmium chloride subcutaneously or by ligating the vessels of one testis. Temperatures were recorded with thermocouple needles without anaesthesia. Neither acute nor chronic cadmium damage to the testes, nor even vascular ligation, significantly changed the normal temperature difference between rectum and testis. The reactions to heating and cooling of ligated and normal testes were very similar. It is suggested that the vascular mechanisms in the adult rat testis prevent excessive heat from being carried into the testis by the internal spermatic artery, but that the scrotum as such is capable of maintaning the testicular temperature low enough in the absence of arterial blood flow.
The Effect of Adrenaline on the Carbohydrate Metabolism in Striated Muscle
Authors: Beviz Andras , Mohme‐Lundholm Ella , Svedmyr Nils
Published: December 2008

Adrenaline increased the concentration of, and changed the relationship between different hexose phosphates in isolated rat diaphragm. This indicated that adrenaline did not only influence the carbohydrate metabolism in striated muscle by activating the enzyme phosphorylase and stimulating the glycogenolysis. An increased glycogenolysis was probably the most significant effect of adrenaline but an activation of the reactions: glucose‐1‐phosphate → glucose‐6‐phosphate; fructose‐6‐phosphate + ATP → fructose‐1–6‐phosphate → ADP also seemed to be of importance.
Renal Blood Flow, Circulation Times and Vascular Volume in Normal Man Measured by the Intraarterial Injection —External Counting Technique
Authors: Ladefoged Jørgen , Pedersen Fritz
Published: December 2008

In six normal young men renal blood flow and renal mean circulation times for red cells and plasma were measured by external counting after injection into the renal artery of Xe‐133, Cr‐51 labelled red cells and 1–131 labelled albumin. Simultaneously the clearances of inulin and PAH and the blood pressure in aorta were measured. Inulin clearance was in average 122 ml/min. 1.73 m', PAH clearance 663 ml/min. 1.73 m2, renal cortical blood flow 5.4 ml/g. min., mean renal blood flow 4.6 ml/g. min., mean circulation time for erythrocytes 4.7 sec., mean circulation time for plasma 5.5 sec. and mean blood pressure in aorta 89 mm Hg. The renal cortical vascular volume was 46 mli 100g. The data on renal blood flow obtained by the external counting technique correlated well with those obtained from the clearance measurements. The mean circulation times were shorter than those measured by other investigators using indicator dilution techniques. The cortical vascular volume, which includes the blood in the renal veins and arteries, was greater than previously found in animal kidneys.
The Effect of Calcium on the Mechanical Response of Single Twitch Muscle Fibres of Xenopus Laevis
Authors: Frankenhaeuser Bernhard , Lännergren Jan
Published: December 2008

The effect of altered external calcium concentration on potassium‐induced contractures in single twitch muscle fibresof Xenopus laeziswas studied. It was found that an increase in [Ca] shifted the curve relating peak tension to membrane potential to lower potential values and that the rate of relaxation was decreased. Decreased [Ca]°shifted the peak tension‐membrane potential curve in the opposite direction and made relaxation quicker. The relation between inactivation of the contractile system and membrane potential was also affected by changes in [Ca]°; increased [Cal]°shifted the curve towards more positive potential values and decreased [Ca]°caused a large shift in the opposite direction. Small effects of altered [Ca]°were seen on the recovery of twitches after a preceding contracture in 190 m M‐K The refractory period was shortened by an increase in [Ca]°and lengthened by a decrease in [Ca]°The rate of action of altered [Ca]°was found to be high, both on twitch amplitude and contracture height, the effects of a change in [Ca]°being seen in less than one second. The results can be satisfactorily explained by assuming that the site of action for these calcium effects is the cell membrane.
Effect of Asphyxia on the Cortical Steady Potential in Adult and Fetal Sheep
Authors: Eidelberg E. , Kolmodin G. M. , Meyerson B. A.
Published: December 2008

The effect of asphyxia on the steady potential measured between the cortical surface and bone has been studied in adult and fetal sheep. During asphyxia the steady potential changed from positivity to increasing negativity and the rate of change was on average five times slower in the fetus than in the adult. This effect has tentatively been attributed to the ability of the fetus to utilize anaerobic sources of energy. although differences in rate of maturation of nerve and glial cells, serving as generators of the SP, may play an important role.
Ionic Binding of Histamine in Mast Cell Granules
Authors: ÅBorg Carl‐Hugo , Novotny Josef , Uvnäs Börje
Published: December 2008

Histamine‐containing granu!es were isolated from rat mast cells by differential centrifugation. The histamine was released on suspension of the granules in a medium containing sodium. By using radioactive sodium (22Ta) the release of histamine was shown to be due to an exchange with sodium at ionic sites in the granules. The affinity of histamine was calculated to he about 10 times that o sodium. The pH dependence of the release of histamine and the uptake of sodium agrees with an ionic binding to weak acid groups [carboxylic groups] and not to strong acid groups (sulphate groups) as previously stated. Whether these hindins groups belong to the heparin or the protein in the granules remains to be decided.
Coagulation Factors and Defibrination Syndrome in Anaphylaxis
Authors: Blombäck Margareta , Johansson Stig‐Arne , Sjöberg Hans‐Erik
Published: December 2008

Coagulation factors were studied in rabbits with induced anaphylaxis and in control rabbits. In the anaphylactic group a decrease in platelets, coagulation factors V, IX, II+VII and fibrinogen was noted as well as an increase in antithrombic activity. In the control group an increase in factor IX was noted. The other factors were unchanged. We believe that increased intravascular coagulation is the cause of the changes in the coagulation factors and that it might at least in part contribute to the pathophysiology of the anaphylactic syndrome. Heparin treatment of conditions with consumption of coagulation factors is discussed.
The Series Elasticity of Active Taenia Coli in Vitro
Authors: ÅBerg A. K. Gunnar
Published: December 2008

The series elastic components (SEC) of the smooth muscle taenia coli of the guinea‐pig have been investigated.

The rate of isotonic shortening after release of an isometrically contracting taenia coli showed that the muscle behaved like a model with contractile elements in series with elastic components. Thus taenia coli has SEC in the same sense as it has been described for striated muscles and heart muscles. At 37°C and full isometric tension the SEC in taenia coli in vitro were measured to be extended on the average 13.1 ± 2.7 per cent of Lo. Maximum “isometric” work developed during an isometric contraction was approximately 30 per cent of the maximum work that the muscle could perform during an isotonic shortening.
Contractures of Single Slow Muscle Fibres of Xenopus Laevis Elicited by Potassium, Acetylcholine or Choline
Authors: Lännergren Jan
Published: December 2008

Contractures were induced in single slow muscle fibres of Xenopus laevis by step increases in external potassium concentration or by application of solutions containing acetylcholine or choline. [K]o needed to evoke a contracture was lower in slow fibres (about 15 mM‐K) than in twitch fibres (about 25 mM‐K). In [K]o near the mechanical threshold tension developed rapidly after a long initial delay. The relation between [K]o and peak tension was extremely steep. Evidence was obtained that the steepness is not due to a regenerative process. In contrast to contractures caused by an increase in [K]o ACh‐ and choline‐induced contractures started without a delay and they were smoothly graded with concentration of the stimulating agent. The differences in the response can be explained if it is assumed that ACh and choline cause a longitudinal potential gradient whereas potassium depolarizes the cell membrane uniformely.
Fibre Components and Cortical Projections of the Elbow Joint Nerve in the Cat
Authors: Andersen H. T. , Körner L. , Landgren S. , Silfvenius H.
Published: December 2008

A method is described for dissection and identification of the afferent elbow joint branch of the musculocutaneus nerve. Conduction velocities of three components in the compound action potential of the joint nerve were determined. Their average conduction velocities were 58–83, 43–57 and 22–42 m/sec. The diameters of the myelinated axons of the elbow joint nerve were measured. The average content of fibres in the nerve was 94. Out of these 6 per cent had diameters between 10 and 13.5 μ, 32 per cent between 7 and 9.9 μ, 29 per cent between 5 and 6.9 μ, 20 per cent between 3 and 4.9 μ and 13 per cent were thinner than 3 μ. On analogy with the observations on the knee joint afferenh it was concluded that the 6 per cent group consisted of fibres from Golgi endings in the joint ligaments and the 32 per cent group of fibres from Ruffini endings in the joint capsule. Cortical potentials were generally evoked in response to electrical stimulation of the Ruffini afferents. Stimulation of the Golgi afferents evoked cortical activity only in some of the preparations. The extent of the cortical projection areas of the elbow joint nerve was mapped. The rôle of the two receptor groups in the neural mechanism of kinesthesis is discussed.
Pressure Relationships in the Bone Marrow Vascular Bed
Authors: Michelsen Kåe
Published: December 2008

The bone marrow tissue pressure was measured indirectly in anesthetized rabbits by measurement of the intramedullary venous pressure through a vein from the bone marrow of the tibia. It varied between 10 and 80 cm of saline and pulsated in synchrony with the arterial blood pressure. The socalled bone marrow pressure was measured through a needle inserted blindly into the bone marrow. It was equal to the venous pressure, but the procedures performed for measurement of the bone marrow pressure, often led to an increase in the venous pressure. Alterations in the arterial pressure and the venous pressure outside the bone caused changes in the same direction in the bone marrow tissue Pressure. Noradrenaline caused a drop, acetycloline a rise in this pressure. The bone marrow tissue was found able to maintain a considerable pressure difference in the long axis of the bone. It seems that the bone marrow cavity, as for the pressure relationships, can be considered as a part of the circulatory system, coupled in between the arterioles within the bone marrow and the veins draining the bone.
The Negative Inotropic Effect of Vagal Stimulation on the Heart Ventricles of the Duck
Authors: Folkow B. , Yonce L. R.
Published: December 2008

Experiments on anesthetized ducks show that the contractility of the heart ventricles of this diving species can be powerfully depressed by the vagal nerves. This vagal negative inotropic effect shows the same characteristic frequency‐response relationship as the vagal negative chronotropic effect and may, at high “physiological‘”discharge rates, reduce contractile force to less than half the control. This vagal negative inotropic influence, as combined with the reflex inhibition of the sympathetic positive inotropic influence, that also occurs when awake ducks dive, can reduce stroke volume below control despite the often profound rise in central venous pressure seen during submersion (Folkow, Nilsson and Yonce 1967).
Protection of the Gastric Mucosa against the Lesions Caused by Reserpine through Degranulaton of Mucosal Mast Cells
Authors: Räsänen Toimi , Taskinen Eero
Published: December 2008

The ulcerating effects of reserpinisation in the gastric mucosa of rats were studied by special observation of the function of the gastric mucosal mast cells and the changes in mitotic activity of the epithelial cells. The significance of degranulation of the mucosal mast cells for the ulcerating effect of reserpine was also studied after the pretreatment of rats with dexamethasone. Immediately after the dexamethasone treatment there was a pronounced decrease in mitotic count of the gastric mucosal epithelium which 2—3 days later when the mast cells of the gastric mocusa were almost completely degranulated was followed by a 2—3 fold increase in mitotic activity as compared with controls. 10 and 20 days later the mitotic count in the gastric mucosal epithelium decreased below the controls values, the mucosal mast cells being re‐granulated over the control values. The changes in mitotic count in the epithelium of duodenum. ileum and colon under the same conditions were scanty. The degranulation of the mast cells was markedly slighter in the intestinal than in the gastric mucosa. In the reserpinized rats the number of mitoses in the gastric epithelium decreased simultaneously with the degranulation of the mast cells. The degranulation of the mast cells in the duodenal mucosa was slighter and no changes in mitotic activity occurred in the duodenal epithelium. Lesions appeared during reserpinisation in the ventricular mucosa. Reserpinisation after the dexamethasone treatment did not cause ulcer formation in the gastric mucosa, nor did it in this phase cause inhibition in the mitotic activity, typical of which was an overshooting 2—3 days after dexamethasone treatment. The mechanism of gastric mucosal ulceration is discussed.
Effect of Ouabain on Glucose Metabolism and on Fluxes of Sodium and Potassium of Human Blood Cells
Authors: Funder Jørgen , Wieth JensOtto
Published: December 2008

A technique for the study of red blood cell (RBC) metabolism, ensuring control of pH, is presented. Ouabain caused a significant reduction of glucose utilization (‐15 per cent) and of lactate production (‐17 per cent) of human RBC incubated at 38d̀ C and a pH of 7.40. 80–85 per cent of potassium influx and 60–70 per cent of sodium efflux were abolished in the presence of ouabain. The amounts of Na and K, normally transported by an ouabain sensitive transport mechanism were compared with the reduction of metabolism, which was found in the presence of ouabain. The reduction of adenosine triphosphate turnover (as estimated from the decrease of lactate production) was found to be equivalent to a movement of 3 moles Na and of 2.5 moles K per mole ATP.
Distribution of Injected L‐3, 4‐Dihydroxyphenylalanine (L‐dopa) in the Adult Rat Testis and Epididymis
Authors: Kormano Martti
Published: December 2008

Previous studies have shown that adult and puberal rat testis is very weakly stained shortly after administration of some vital dyes, while the excurrent ducts are heavily stained (Kormano 1967). These observations suggest the existence of barrier mechanisms in the testis which prevent some substances from being carried into the seminiferous tubules and to a great extent even into the intestitial tissue.
133Xenon‐Radiospirometry in Rabbits with Some Observations on Unilateral Hypoxia
Authors: Dale Knut
Published: December 2008

The application in the rabbit of a radiospirometric technique using133Xenon and external detectors is described. The ventilation and the perfusion could be measured separately for each lung. In unilateral hypoxia the method revealed a reduced perfusion of the hypoxic lung.
Effects of Some Monovalent Anions on Fluxes of Na and K, and on Glucose Metabolism of Ouabain Treated Human Red Cells
Authors: Funder Jørgen , Wieth Jens Otto
Published: December 2008

The present work deals with the effects of the anions Cl, Br, NO3, I, SCN, and HCO3on Na and K fluxes, and on glucose metabolism of human red cells suspended in isotonic electrolyte media at 38d̀ C and pH 7.40 in the presence of ouabain. When 120 m M Cl of the isotonic medium was substituted by the anion concerned, Na influx and K efflux were unaffected by Br, increased about 30 per cent by NO3and I, but increased 200 to 250 per cent in the presence of SCN. Substitution of 120 mM Cl by HCO3increased Na influx into red cells by 250 per cent. In contradistinction K efflux was reduced by 25 per cent. The increase of Na influx was linearly related to HCO3concentration at pH 7.40.

At intracellular Na concentrations between 10 and 35 meq/kg cell water the rate constant of Na efflux was close to 0.15 h‐1in the presence of all 6 anions studied. At external K concentrations from 5 to 7.6 meq/l potassium influx into ouabain treated cells suspended in a chloride medium was thrice as big as the influx calculated from the flux ratio equation M1/M0=K0/K1. exp (‐zEF/RT). A similar condition was found in the presence of Br. In all other media studied (NO3.l, SCN, and HCO3) the ratio between the measured fluxes of potassium agreed with the calculated values of flux ratio for passive, independent fluxes.

A net flux of water into the cells was observed in cells suspended in SCN and HCO3media. In the same media the gain of Na in cells exceeded K loss. The relation of water net flux to the net gain of cations was 6.5–7.3 g water per meq. The rate of glycolysis was unaffected by the substitution of Cl by HCO3, was reduced by 15 per cent in the presence of Br, NO3, and I, and decreased by 30 per cent in the presence of SCN.
Interference of Light on the Determination of Low Glucose Concentrations with Glucose Oxidase
Authors: ÅBerg Bo
Published: December 2008

A method for measuring glucose concentrations down to 10 μM/L is described. This is a modification of a method based on a commercially available glucose‐oxidase reagent. Some factors which are important for good reproducibility were investigated. Most important is the light sensitivity of the chromogenic reaction. The absorbance decrease which results from illumination is, however, reversible in the dark. If the samples are kept in darkness until the absorbance is measured and a suitable photometer is used, the method has a good reproducibility and is simple to perform.
A Possible Role Played by Central Monoamine neurones in Thermo‐Regulation
Authors: Corrodi Hans , Fuxe Kjell , Hökfelt Tomas
Published: December 2008

The effect of a cold and warm environment on the activity of the central catecholamine (CA) and 5‐hydroxytryptamine (5‐HT) neurones has been studied with the help of a combined biochemical and histochemical approach using inhibitors of the tyrosine and tryptophane hydroxylase. The central noradrenaline (NA) and 5‐HT neurones of rats kept at: 40d̀ C were found to increase their state of neuronal activity. whereas the 5‐HT but not the CA neurones of rats kept at ± 3d̀ C showed a decreased neuronal activity. These results indicate that the central NA and 5‐HT neurones participate in thermo‐regualtion.
Effects of Acetylcholine and Biogenic Amines on Pulmonary Smooth Muscle in the African Lungfish, Protopterus Aethiopicus
Authors: Johansen Kjell , Reite Ola B.
Published: December 2008

Smooth muscles from the glottis sphineter and pulmonary parenchyma were excised from freshly killed specimens of the African lungfish,Protopterus aethiopicus, and mounted in a bath of Ringer solution while responses to pharmacological agents were studied. Both muscle preparations gave qualitatively similar responses. Acetylcholine caused contraction which was abolished by pretreatment with atropine. Histamine and serotonin also contracted the muscles, their effects being diminshed by mepyramine and methysergide. Adrenaline and noradrenaline relaxed the muscle preparations. Neither regitine nor propranolol affected this response. Isoproterenol had a slight relaxing effect. Anoxia and hypercapnia did not influence the contractile state of the muscles.
Studies on the Time Course of Histamine Release and Morphological Changes Induced by Histamine Liberators in Rat Peritoneal Mast Cells
Authors: Bloom Gunnar D. , Fredholm Bo , Haegermark ÖSten
Published: December 2008

The histamine release process in rat peritoneal mast cells, exposed to histomine liberators, can be terminated by the addition of ice‐cold salt solution. This was taken advantages of for studies on the time course of histamine release and concomitant morphological changes induced by compound 48/80, bee venom and n‐decylamine. After addition of compound 48/80 or bee venom, histamine was released in about 10 sec at 37/dG C and about 30 sec at 22/dG C. independently of the liberator concentration. AT 22/dG C the release was preceded by a lag period, which was shorter with higher liberator concentrations. The enzyme inhibitors potssium cyanide and N‐ethylmaleimide did not alter the duration of the reaction induced by compound 48/80 or bee venom, although they lowered the final release. The release curve showed a different shape when histamine was released by n‐decylamine. The morphological changes, studied both in the light and electron microscope, were found to be correlated to the histamine release.
Histamine Release from Isolated Rat Peritoneal Mast Cells Induced by Adenosine‐5‘‐Triphosphate
Authors: Diamint Bertil , Krüger Per Göran
Published: December 2008

Histamine release from isloated rat mast cell is induced by ATP (10‐5— 3 × 10‐5M). The activity found in an ADP‐perepatation was shown to be due to contamination with ATP, purified ADP has no activity. AMP, 3′ 5′ AMP, PCr and PEP were without histamine releasing activity. Histamine release induced by ATP was compared with that caused by compound 48/80 with respect to the influence of Ca++, Mg++, Zn++, ouabain, DNP, oligomaycin and glucose. The results are interpreted to indicate that ATP and compoundf 48/80 release histamine by mechanisms that in certain respects differ from each other. The histamine releasing effect of ATP is discussed in relation to the enery‐requiring mechanism that iis known to be involved in histamine release by compound 48/80.
Degranulation and Histamine Release, Two Consecutive Steps in the Response of Rat Mast Cells to Compound 48/80
Authors: Thon I. L. , Uvnäs B.
Published: December 2008

Isolated rat peritoneal mast cells were exposed to compound 48/80 in A isotonic salt solution and in B isotonic sucrose solution. In both cases degranulation and histamine release occurred. In A all the released histamine appeared dissolved in the suspension medium, the discharged granules having lost their histamine. In B the discharged granules were show to retain histamine. These granules released their histamine when suspended in a NaC1‐containing medium. Depleted granules could be refilled with histamine by suspension in a histamine‐containing medium and again depleted of the amine by exposure to sodium chloride. The proposal is made that the histamine release induced by compound 40/80 is a two stage process, a primary energy‐requiring transport of histamine‐containing granules to the outside of the mast cell and a secondary nonenergy‐requiring physico‐chemical process, an extracellular cation exchange in the shed granules between histamine and cations, mainly sodium in the tissue fluid.
Gastric and Duodenal Ulcers in Cats Following Reserpine
Authors: Emås Sverre , Fyrö Bengt
Published: December 2008

The incidence of gastric and duodenal ulcers following reserpine was studied in cats. A single injection of 0.10 mg/kg of reserpine produced the highest incidence of antral ulcers (89 per cent) after 12 hrs and of duodenal ulcers (50 per cent) after 24 hrs. No ulcer was detected 8 days or more after the single injection. Reserpine injected every 24 hr for 2 to 4 days produced a lower incidence of antral ulcers than a single injection. In cats injected daily with reserpine for 6 days or more no ulcer was detected. Reserpine produced no ulcer in the oxyntic gland area. The ulcerogenic effect of reserpine remained after adrenalectomy. Truncal vagotomy or pretreatment with reserpine reduced the incidence of ulcers and also the acid response to reserpine. 0.10 mg/kg of reserpine was more effective to produce ulcer and to stimulate acid secretion than 0.03 mg/kg/. The results suggested that the transient ulcerorgenic effect of reserpine was related to its effect on acid secretion.
A Micromethod for the Determination of Choline Acetylase in Individual Cells
Authors: Buckley G. , Consolo S. , Giacobini E. , McCaman R.
Published: December 2008

A micromethod is described for the determination of choline acetylase in single cells. The method involves the use of [14C] acetyl CoA adn choline as suvstrates giving rise to [14C] acetylcholine which is quantitatively precipitated as a reineckate. After washing the reineckate to remove the residual radioactivity of the substrate, the labelled reineckate is dissolved in acetone and counted in a scintillation counter. The method is suitable for the quantitative determination of enzyme activities in 50–100 individual cells per experiment. The sensitivity of the method is 10‐13 moles of [14C] acetylcholine/hour.
Intracellular Variations of Na and K in Isolated Nerve Cells
Authors: Giacobini Ezio , Hovmark Stefan , Kometiani Zurab
Published: December 2008

The variations of intracellular Na and K content in isolated crustacean sensory neurons were examined in different experimental conditions with the help of a sensitive microflamephotometric technique. In the experiments with physiological solution, after the isolation of the sensory neuron, the ionic events can be divided into two periods. During the first period, the initial period, a continuous recovery from the initial distortion of the ionic contents is going on. The intracellular cationic content is influenced during this period by at least two processes acting simultaneously and counteracting each other; one depending on the manipulation of the cell, the other on the active transport. If the active transport mechanism is inhibited, (e.g.under the effect of ouabain or in K free or Na free medium) the recovery does not take place. The second period starts about 1 hr later and is characterized by stationary levels of Na and K which—in Van Harreveld's solution—are close to physiological levels. This period may continue during at least 5 hrs. Tetrodotoxin (0.0167 μg/m1) glucose (1 mM) and shortlasting physiological stimulation (about 30,000 impulses) do not significantly change the intracellular Na or K.
Thermoregulatory Responses to Arm Work, Leg Work and Intermittent Leg Work
Authors: Nielsen Bodil
Published: December 2008

Nielsen, B. Thermoregulatory responses to arm work, leg work and intermittent leg work. Acta physiol. scand. 1968. 72. 25–32.

The increase in esophageal temperature during continuous work on a bicycle ergometer with the arms and with the legs was compared. Also the effect of intermittent leg work (30 sec rest/work intervals) was compared to that of continuous work. At the same rate of metabolic energy production the esophageal temperature in the steady state was about the same independent of the different degree of anaerobicity and the different neuromuscular factors. It is therefore suggested that chemical factors liberated in proportion to the aerobic prosesses is responsible for the temperature setting during work. The sweat rate and the skin circulation expressed as conductance of the peripheral tissues carried in proportion to the total heat production independent of neuromuscular factors.