bluuebunny/crossref_metadata_2025 huggingface dataset:
The Tissue Distribution of Radioactivity Following the Injection of Varying Levels of Fatty Acid Labeled Chylomicrons in the Rat
Authors: Belfrage Per , Borgström Bengt , Olivecrona Thomas
Published: December 2008

Belfrage, P., B. Borgström and T. Olivecrona. The tissue distribution of radioactivity following the injection of varying levels of fatty acid labeled chylomicrons in the rat. Acta physiol. scand. 1963. 58. 111–123. — H3‐palmitic acid labeled chylomicrons in doses of 4–124 mg lipid were injected intravenously into rigorously carbohydrate‐fed rats. The radioactivities in blood, liver, adipose tissue, spleen, lungs, kidneys, and muscles were studied. For doses of 4 to 33 mg lipid the disappearance of label from the blood followed an exponential rate which was similar for these doses and corresponded to half‐lives of 2.2 to 3.5 minutes. The maximal radioactivities found in the liver were also similar for these doses and ranged from 40 to 51% of the injected radioactivity. For doses of 64 and 124 mg lipid the disappearance curve was more complex and the label disappeared more slowly from the blood. The maximal radioactivity found in the liver was also decreased. It is concluded that at these doses the system was overloaded. The spleen and the lungs took up significant amounts of chylomicron fatty acids as evidenced by initial peaks in the radioactivity curves for these tissues. The kidneys, the heart, and the muscles showed a slower rise of radioactivity and presumably took up mainly recirculated fatty acids. The adipose tissue also seemed to take up mainly recirculated fatty acids.
The Role of the Cardiovascular Response in the Resistance to Asphyxia of Avian Divers
Authors: Hollenberg N. K. , Uvnäs B.
Published: December 2008

Hollenberg, N. K. and B. Uvnäs. The role of the cardiovascular response in the resistance to asphyxia of avian divers. Acta physiol. scand. 1963. 58. 150–161. — Submersion asphyxia in unanaesthetized ducks produced a characteristic circulatory response consisting of a pronounced bradycardia, increased blood pressure, decreased splanchnic and skin blood flow and little change in skeletal muscle blood flow. The circulatory responses to asphyxia were completely abolished by denervation of the carotid chemoreceptors and baroceptors. Continuous measurement of arterial oxygen saturation showed a biphasic fall during asphyxia, decreasing very rapidly during the first 40 sec, and then falling much less rapidly at the time splanchnic and skin blood flow reached a minimum. It was concluded that the marked ability of divers to withstand asphyxia is related to their circulatory response. The net result of the circulatory response is to decrease the oxygen supply to areas that can easily withstand an oxygen deficit for a limited period, conserving the available oxygen stores for tissues more sensitive to a lack of oxygen. Evidence is presented which suggests that the above described response is due to chemoreceptor stimulation.
Studies on SO2, NO2 and NH3: Effect on Ciliary Activity in Rabbit Trachea of Single in Vitro Exposure and Resorption in Rabbit Nasal Cavity
Authors: Dalhamn Tore , Sjöholm Jan
Published: December 2008

Dalhamn, T. and J. Sjöholm. Studies on SO2, NO2 and NH3: effect on ciliary activity in rabbit trachea of single in vitro exposure and resorption in rabbit nasal cavity. Acta physiol. scand. 1963. 58. 287—291. — One of the factors which determine the toxicity of pulmonary irritant gases, etc., presumably is their action on the ciliated epithelium of the respiratory tract. The degree to which such gases are resorbed in the mucous layer of the respiratory passages must also be taken into ac‐count when hygienic limits and allied questions are discussed. The present paper illustrates these two factors, viz., ciliostatic action and resorption, by experiments with three common respiratory irritant gases — sulphur dioxide, nitrogen dioxide and ammonia. As regards concentration required to arrest tracheal ciliary activity in vitro, the three gases varied considerably. The degree of resorption in the upper respiratory tract also showed wide variations. It seems probable that a gas which even in low concentration rapidly impairs ciliary activity and which is resorbed to a relatively slight degree can penetrate deeper into the bronchial tree and thus, on the stated assumptions, be more toxic than gases with the reverse characteristics.
Studies on the Reactions of the Cutaneous Vessels to Cold Exposure
Authors: Folkow B. , Fox R. H. , Krog J. , Odelram H. , Thorén O.
Published: December 2008

Folkow, B., R. H. Fox, J. Krog, H. Odelram and O. Thorés. Studies on the reactions of the cutaneous vessels to cold exposure. Acta physiol. stand. 1963. 58. 342—354. — Some inter‐relationships between the mechanisms responsible for the vascular responses to intense cooling have been studied in cats and in man. The results suggest that both the initial intense blood flow decrease and the subsequent cold vasodilatation are complex in nature, each appearing to depend on a number of quite different mechanisms which are briefly discussed. There are good reasons to assume that the relative importance of each of the mechanisms involved may vary considerably depending on the circumstances, and that under certain conditions one or more may even be eliminated without changing the trend of the net response.
Smooth Muscle Phosphorylase and Enzymes Affecting its Activity
Authors: Mohme‐Lundholm Ella
Published: December 2008

The activity, per mg protein, of purified phosphorylaseaprepared from smooth muscle (bovine tracheal muscle) was found to be approximately one half that of the corresponding purified enzyme from striated muscle. Under the action of phosphorylase phos‐phatase (PR enzyme) from tracheal or skeletal muscle, phosphorylaseawas converted to phosphorylasebcoincidently with liberation of inorganic phosphate. A higher concentration of AMP was required for activation of smooth muscle phosphorylasebthan for activation of striated muscle phosphorylaseb. Partially purified phosphory‐lase phosphatase from bovine tracheal muscle had, per mg protein, approximately one‐fourth the activity of the corresponding enzyme from rabbit skeletal muscle. In the presence of ATP and magnesium ions phosphorylaseawas synthetized from phosphorylasebby phosphorylasebkinase prepared from tracheal or skeletal musclr. Inactivc phosphorylasebkinase was activated by adenosine‐3′–5′‐phosphate, by calcium ions, and by increasing the pH of the incubation solution to 8.4.
Chemical and Histochemical Evaluation of the Distribution of Catecholamines in the Rabbit and Guinea Pig Hearts
Authors: Angelakos E. T. , Fuxe K. , Torchiana M. L.
Published: December 2008

Chemical determinations of nor adrenaline (NA), adrenaline (A), and dopamine (DA) were made in the right and left atria and ventricles (RA, LA RV. LV) of rabbit and guinea pig hearts. The concentration of these amines was also studied in the sino‐auricular (SA) node of the rabbit. Some of these tissues were also examined for the distribution of catecholamines using a histochemical fluorescence technique. NA was the predominant catecholamine present in atria and ventricles. It was more concentrated in the RA than LA and in the RV than in the LV of the rabbit and guinea pig. In the latter KA was distinctly higher in the atria than in the ventricles. By contrast A was more concentrated in ventricles than in atria of both species and accounted for about 5–10 per cent of the total catecholamine content. DA was found pre‐dominantely in the atria, more in RA than in LA. High concentrations of DA were found in the SA node region. Histochemical studies on rabbit tissues showed that the catecholamines were found within nerve structures. A high density of fluorescent fibers and fiber bundless was found in the SA node region. An excellent correlation between the histochemical and chemical findings was obtained when both NA and DA were considered.
Noradrenaline Storage in Skeletal Muscle1
Authors: Sedvall Göran
Published: December 2008

Noradrenaline levels in skeletal muscle extracts purified by cation exchange chromatography were analyzed fluorimetrically by the THI procedure. The average amount of nor‐adrenaline found in muscles from different species varied between 0.031 and 0.119μg/g. Adrenaline was found only in minute amounts, never constituting more than 11% of the sum of noradrenaline and adrenaline. In the cat, a constant relation was found between the noradrenaline values in different muscles. Preganglionic sympathetic denervation caused a slight increase in muscle noradrenaline during the first days. Noradrenaline levels in the muscles tended to rise during the first two days after postganglionic sympathetic denervation, only to decline abruptly after about 48 hours. Forteen days after postganglionic denervation the muscles were practically devoid of noradrenaline, indicating that skeletal muscle noradrenaline is stored almost exclusively in postganglionic sympathetic nerves.
Gastric Acid Secretory Responses to Gastrin and Histamine in Dogs Before and After Vagal Denervation of the Gastric Pouch
Authors: Andersson Sven , Olbe Lars
Published: December 2008

Vagal denervation of the HCl glands by transforming Pavlov pouches into Heidenhain pouches markedly reduced the submaximal acid secretory response to exogenous gastrin in four fasting dogs but reduced the submaximal acid secretory response to histamine in only one of four dogs, three dogs being common to the gastrin and histamine studies. The results suggest that a continuous vagal discharge on the HCl glands is necessary to maintain the sensitivity of the glands to gastrin. An interpretation is presented for the different effects of vagal denervation on the sensitivity of the HCl glands to gastrin and histamine.
Gastric Acid Secretion in Sympathectomized Gastric Fistula Gats before and during Reserpine Treatment and in Gastric Fistula Gats during Guanethidine Treatment1
Authors: Emås Sverre
Published: December 2008

Daily intramuscular injections of reserpine for 3 days or more elevate basal gastric secretion of acid and increase the acid secretory responses of nonanesthetized gastric fistula cats to intravenous histamine and gastrin. The possibility that the gastric hypersecretion of the reserpine treated cats might be due to the reduction or loss of adrenergic nerve influences on the stomach was investigated. Neither preganglionic nor pre‐and postganglionic sympathetic denervation of the stomach altered basal acid secretion. Nor did such denervations alter gastric secretory responses to histamine and gastrin except in one of three cats, in which the responses to histamine increased after pre‐and postganglionic denervation. Reserpine treatment produced hypersecretion to the same degree in sympathectomized as in ordinary gastric fistula cats. Daily subcutaneous injections of guanethidine produced no reserpine‐like effects on gastric acid secretion. The results indicate that the adrenergic nerves innervating the stomach normally exert no direct influences on basal acid secretion or on the excitability of the parietal cells to the secretory stimuli used and it was concluded that the hypersecretion of reserpine treated cats is not directly due to the reduced or abolished influences of the adrenergic nerves on the stomach.
Cellular Localization of Monoamines in the Spinal Cord
Authors: Carlsson Arvid , Falck Bengt , Fuxe Kjell , Hillarp Nils‐Åre
Published: December 2008

The cellular localization of monoamines in the spinal cord of the mouse and the rat has been studied with the use of a fluorescence method for histochemical demonstration of certain cate‐cholamines and tryptamines in combination with a pharmacological approach and transection experiments. Strong evidence was obtained for the view that noradrenaline (NA) and 5‐hydroxytryptamine (5‐HT) are localized in special systems of nerve tracts which from supraspinal centers descend in the lateral and anterior funiculi to terminate in the gray matter and which belong to monoaminergic neurons. The amines show a massive accumulation in the terminal part of the nerve fibres. This strongly indicates that both amines serve as synaptic transmitters in the spinal cord. Many nerve terminals containing NA or 5‐HT are present in the anterior horns. They are more scarce in the posterior horns. Terminals of both kinds are highly concentrated in the sympathetic lateral column where most—if not all—of the nerve cells are surrounded by them. They originate—at least mainly—from a tract descending in the dorsolateral funiculi. This localization of the descending fibres suggests that they arc identical with the inhibitory fibres going to the sympathetic column.
Serum and Urine Allantoin in Pregnancy and Lactation in the Rat
Authors: Morgan E. H. , Hanson A.
Published: December 2008

Allantoin and uric acid were measured in the urine and serum of virgin rats and reproducing rats at various times during pregnancy and lactation, and in the serum and amniotic fluid of foetuses on the 21st day of pregnancy. Urinary allantoin excretion increased steadily during pregnancy and remained high during the first 20 days of lactation but thereafter declined. Serum allantoin concentrations were higher in pregnant and lactating rats than in virgin rats. Amniotic fluid allantoin concentrations were greater than those of foetal serum, which in turn exceeded the maternal serum values. Uric acid concentrations were lower in serum and much lower in urine than allantoin concentrations in all samples examined.
A Method for the Determination of the Total Carbon Dioxide Content of Frozen Tissues
Authors: Pontén U. , Siesjö B. K.
Published: December 2008

A method is described for the determination of the total acid‐labile carbon dioxide of a tissue after freezing the tissue in situ with liquid nitrogen. The method utilizes a single diffusion step with the absorption of liberated carbon dioxide into hydroxide and subsequent titrimetric determination of the amount of carbon dioxide. Experiments performed on rat brain tissue showed that the transfer of the frozen tissue from liquid nitrogen to the diffusion chambers must be performed in an atmosphere which is free from carbon dioxide and water vapour. Control experiments have shown that if these precautions are taken, the total acid‐labile carbon dioxide can be accurately determined. Determinations of the total carbon dioxide content have been performed on 380 brains with 3–4 single analyses on each brain. Statistical analysis on the entire material shows that the total carbon dioxide content of a brain sample can be determined with a standard error of 0.06 ümoles/g if the sample weight is kept in the region of 40 to 150 mg.
Studies on the Thrombolytic Activity of a Protease from Aspergillus Oryzae
Authors: Bergkvist Rolf , Svärd Per Olov
Published: December 2008

The fungal protease was administered intravenously in repeated doses to cats. The effect on clotting time, fibrinogen level, fibrinolytic and activator activity, and serum inhibitor activity of each dose was determined. It is concluded that doses of the enzyme which do not overcome the natural inhibitor capacity of the animals have no untoward effects on these parameters. Over‐dosage has, however, fatal consequences. Using tolerable doses, evidence was obtained for in vivo lysis of experimental venous thrombi. The assumption is advanced that a reversible complex between the enzyme and one of the plasma inhibitors is responsible for the in vivo thrombolytic effect. When in contact with fibrin, the protease I is competitively removed from the complex finally resulting in a dissolution of the clot.
The Influence of Reserpine on the Intracellular Distribution of Noradrenaline in the Rat Heart
Authors: Johnson G. E.
Published: December 2008

Rats, exposed to a cold stress or treated with a low dose of reserpine, were killed at various times and their hearts removed and homogenized in phosphate buffer. Subsequent centrifugation of the homogenate produced three fractions 1) a coarse fraction following low speed centrifugation 2) a particulate fraction and 3) a supernatant fraction obtained by high speed centrifugation of the first supernatant. These 3 fractions plus aliquots of the total homogenates were assayed for noradrenaline content. Following reserpine, 0.1 mg/kg, a preferential fall in the noradrenaline concentration in the supernatant fraction occurred after 1 hour, without any fall in the noradrenaline content of the particulate fraction. Two hours after reserpine the total noradrenaline content was reduced to about one‐half, with the same relative proportion of amines in the particulate fraction and in the supernatant as after 1 hour. Cold stress, inducing a strong increase in noradrenaline release, failed to alter either the total noradrenaline content of the hearts or the intracellular distribution of this cate‐cholamine. It is suggested that the amine fall in the supernatant fraction after reserpine results from an impairment in the release of noradrenaline from the particulate fraction.
Regional Distribution of Circulating Blood During Submersion Asphyxia in the Duck
Authors: Johansen Kjell
Published: December 2008

Regional blood flow distribution in ducks was estimated from fractional distribution of Rb86CI. A comparison was made between normally breathing ducks and submerged ducks. The data document that conspicuous changes in regional blood flow take place upon submersion. The skin, skeletal muscle, and organs of the gastrointestinal system showed a marked decrease in activity in the submerged condition down to an average of 3.9 % for the gizzard, 29.4 % for skin excised from the thorax and 11.0 % for gastrocnemius muscle. Surprising exceptions to this were displayed by tissues in the cranial part of the animals. Thus both skin and muscle from the head region showed an increase in activity during submersion. The same was true for the excised eye. The esophagus similarly showed an increased activity in the submerged animals. The myocardium from both atria and ventricles showed a striking increase amounting to 4.1 times higher activity in the left ventricular myocardium in the submerged animals. The change in vasomotor constrictor tone taking place upon submersion is thus highly selective and possibly segmentally oriented giving an increase in peripheral resistance to most organs posterior to the heart while the most cranial tissues seem to be subjected to a general decrease in vasoconstrictor tone with an increased blood flow. Activity in the kidneys was markedly consistent and 9.1 % of the value found in normally breathing animals. The adrenals showed an interesting increase in activity on the average as high as 4.9 times the value in normally breathing animals.
The Effect of Exercise on the Vascular Bed of Skeletal Muscle
Authors: Kjellmer Ingemar
Published: December 2008

A plethysmographic method is described which has been used for continuous recording of volumetric changes in the isolated calf muscles of cats. Venous outflow, arterial and venous pressures were measured simultaneously. Steady state exercise was mimicked by stimulation of the motor nerve. Changes occurring in the resistance vessels, in the capacitance vessels and in the capillary filtration coefficients were recorded. Exercise provoked a dilatation of the resistance vessels, an increase of the capillary filtration coefficient (dilatation of the precapillary sphincters) and a distension of the capacitance vessels. The degree of dilatation in all three vessel sections was related to the severity of exercise. It was shown that the increase in regional blood volume (dilatation of the capacitance vessels) is caused mainly by an increased pressure head reaching the capacitance vessels and not by an active venous dilatation. During exercise there was a net outward capillary filtration due to an elevated capillary hydrostatic pressure and augmented by an increased capillary surface area available to blood flow. The elevation of capillary pressure was caused by a dilatation, which affected the precapillary resistance vessels relatively more than the postcapillary.
Acute Effects of Prolonged, Heavy Exercise on the Concentration of Plasma Lipids and Lipoproteins in Man
Authors: Carlson Lars A. , Mossfeldt Folke
Published: December 2008

The concentration of triglycerides, cholesterol and phospholipids in plasma and in ultracentrifugally separated plasma lipoproteins was studied in normal persons during participation in 1962 and 1963 in a yearly skiracing. The skiing time was around 8–9 hours. In the group studied in 1962 as well as in the 1963 group there was a significant fall in the concentration of triglycerides and phospholipids in plasma. When the 1962 group was studied during ordinary activities with identical caloric intake and at identical times as during the skiing no significant changes were found in the plasma lipids. The most pronounced decreases of the plasma lipids was in the triglyceride fraction and this decrease was directly and highly significantly correlated to the fasting triglyceride concentration. About three quarters of the decrease in triglyceride concentration was due to a decrease in the amount of triglycerides in the very low density lipoproteins. The triglyceride concentration in the low and the high density lipoprotein classes also decreased. The decrease of triglycerides was directly correlated to the fasting level in each lipoprotein class. No significant changes were observed in the cholesterol content of any of the lipoproteins. The phospholipid concentration, however, decreased in all three lipoprotein classes. The most pronounced decrease of phospholipids was found in the high density lipoproteins. Mechanism(s) for these changes in the concentration of the plasma lipids and lipoproteins during prolonged, heavy exercise were discussed.
The Effect of Adrenaline on the Hexosephosphate Content of Vascular Smooth Muscle
Authors: Beviz Andras , Mohme‐Lundholm Ella
Published: December 2008

In experiments on isolated vascular smooth muscle adrenaline at a concentration of 10–3caused a 2‐to 3‐fold increase in the content of glucose‐6‐phosphate, fructose‐6‐phosphate, fructose‐1–6‐diphosphate and dihydroxyacetone phosphate during isometric contraction 7 min after addition of the drug. This action of adrenaline was manifest both under aerobic and under anaerobic conditions, and in the presence as well as in the absence of glucose. Fructose‐1–6‐diphosphate showed a relatively greater increase than fructose‐6‐phosphate. — Since in previous experiments on vascular muscle no glycogeno‐lytic effect of adrenaline had been detectable, the possibility that hexosephosphates was formed from some other carbohydrate metabolite is discussed.
The Time Course of the Disappearance of Noradrenaline and 5‐Hydroxytryptamine in the Spinal Cord after Transection
Authors: Andén Nils‐Erik , Häggendal Jan , Magnusson Tor , Rosengren Evald
Published: December 2008

The rabbit spinal cord was transected in the upper thoracic region. Below the lesion the noradrenaline disappeared almost completely between the third and seventh day after the operation. The 5‐hydroxytryptamine was depleted between the fifth and seventh day. The disappearance of these amines was much slower than that of the noradrenaline in the rabbit iris after excision of the superior cervical ganglion. There was no significant increase of the monoamine levels above the transection of the spinal cord.
Adrenergic Mechanisms in the Pupillary Light‐Reflex Path
Authors: Dahlström Annica , Fuxe Kjell , Hillarp Nils‐Åke , Malmfors Torbjörn
Published: December 2008

On the basis of the known effects of reserpine on the eye, the presence of monoaminergic mechanisms in the light‐reflex path of the rat was studied with the use of a fluorescence method for the localization of catecholamines and 5‐hydroxytryptamine at the cellular level. The nucleus of Edinger‐Westphal — but not the large‐celled nuclei of the oculomotor complex — was found to receive abundant nerve fibres which show a massive accumulation of a primary cateholamine, in all probability nor‐adrenaline. There is little doubt that the nerves are adrenergic synaptic terminals. This adrenergic system is so richly developed that is must be assumed to play an important role in the regulation of the activity of the visceromotor outflow to the eye. Except this system and the adrenergic neurons recently discovered (Malmfon 1963) in the retina, no other monoaminergic mechanisms have so far been detected with certainty in the light‐reflex path. Abundant fibres of both the adrenergic and 5‐hydroxytryptaminergic type terminate in other parasympathetic (e. g. the dorsal motor nucleus of the vagus) and also sympathetic nuclei (c. g. the sympathetic lateral column of the spinal cord). 5‐hydroxytryptamine and noradrenaline in the central nervous system are thus not confined to action upon the parasympathetic and sympathetic systems respectively. — Current views on the central action of reserpine are discussed on the basis of the findings.
Dynamic Response of Chest Wall and Lung Injuries in Rabbits Exposed to Air Shock Waves of Short Duration
Authors: CLEMEDSON CARL‐JOHAN , JUNSSON ARNE
Published: December 2008

The movements of the chest walls of rabbits exposed to steep‐fronted air shock waves of short duration produced by 50 g spherical charges of TNT were recorded by means of a mechano‐electric motion transducer originally developed for this investigation. The main purpose has been to study the correlation between the deformations of the chest and the damage inflicted to the underlying organs, especially the lungs. The motion parameters, amplitude, velocity and acceleration of the chest wall, were correlated to the physical characteristics of the shock wave as well as to the lung injury produced. The lung injuries were found to be highly correlated to the impulse of the incident shock wave, and also, although to a lesser degree, to the maximum overpressure of the shock wave, and to the velocity and acceleration acquired by the chest wall. The correlation of the lung injuries to the maximum amplitude of the inward displacement of the chest wall, on the other hand, was found to be much lower or even uncertain. The following critical values of the motion parameters were established. If the chest wall receives an impulse load of such a strength and duration that an inward relative movement results with a velocity of more than 15 m se& attained within a period of time of 150–200 ps, i. e. involving accelerations of the order of 104 g, there is a high probability that a severe lung injury will result. Corresponding maxi mum amplitudes of the displacement of the chest wall were 5 to 7 mm. The lower limit of effective reflection pressures and impulses causing severe lung injuries were 10 bar and 1.5 gf sec cm‐2, respectively. The biomechanical events occurring in the exposed chest are discussed in some detail.
Spermidine and Spermine in Rat Tissues at Different Ages
Authors: Jänne J. , Raina A. , Siimes M.
Published: December 2008

Concentrations of spermidine and spermine in fifteen different tissues of male and female rats aged three months were determined, using amido black as the quantitative reagent, after paper electrophoretic separation of the amines. The changes in the concentrations of these polyamines in relation to age were followed by determinations from six tissues of newborn rats and of male rats aged 1, 3 and 9 months. At the age of three months the largest amounts of the polyamines were found in the liver and the thymus, 900 to 1600 mμmoles of spermidine and 700 to 900 mμmoles of spermine per g wet weight. No great sex differences were observed. In most tissues the molar concentration of spermidine was higher than that of spermine. The spermidine content in every tissue studied decreased with increasing age, the fall being most marked during the first month of life. The spermine content as a rule increased somewhat during the first month and then remained nearly constant or decreased slightly. Consequently, the molar ratio spermidine/spermine was highest immediately after birth, decreasing in the liver, for instance, from 4.52 to 0.84 during 9 months. In the brain, in contrast to the other tissues investigated, it increased from 1.31 to 2.08 during the first 9 months.
On the Silent Period and Golgi Tendon Organs of the Soleus Muscle of the Cat
Authors: Jansen J. K. S. , Rudjord T.
Published: December 2008

The silent period in the soleus during twitch contractions has been studied in intercollicularly decerebrated cats. The duration of the silent period was independent of the initial tension in the muscle and remained constant in spite of large variations in the twitch tension with springs of varying compliances inserted in series with the muscle. The responses of 42 tendon organs of the soleus to twitch contractions, passive stretch and fused tetanic contractions have been determined in Nembutal anaesthetized cats. The majority of the tendon organs had appreciably lower thresholds to active contraction than to passive stretch of the muscle. They were all excited by isometric twitches developing less than 160 g tension. There was an approximately linear relationship between the discharge frequency of the tendon organs and the tension in the muscle during isometric, graded, fused tetanic contractions of the muscle. The slope of this relationship varied between 2 and 18 imp/sec/100 g. It is concluded that the duration of the silent period in the decerebrate cat is primarily determined by the pause in the discharge of the primary endings of the muscle spindle during the twitch.
The Disappearance of Acetic Acid and Acetate from the Cat's Stomach and its Influence on the Permeability for Hydrochloric Acid
Authors: Flemström G. , Frenning B. , ÖBrink K. J.
Published: December 2008

Experiments were performed on anæstethized cats to study the diffusion of acetic acid out of a nonsecreting stomach and its effect on the gastric permeability for hydrochloric acid. Acetic acid diffuses more rapidly than hydrochloric acid out of the stomach. The diffusion of hydrochloric acid is increased by an instillationofacetic acid. The acidityofthe instilled hydrochloric acid decreases more rapidly and reaches lower end‐values. There is also a larger initial dip in chloride concentration. A mixture of sodium acetate and hydrochloric acid was found to have a similar effect on the permeability for hydrochloric acid.
Accommodation in Myelinated Nerve Fibres of Xenopus Laevis as Computed on the Basis of Voltage Clamp Data
Authors: Frankenhaeuser B. , Vallbo Å. B.
Published: December 2008

The equation system earlier derived from the voltage clamp analysis on myelinated nerve fibres from Xeonpus laevis was programmed for a digital computer. The response of the nerve model to linearly rising currents was computed for a number of quantitative modifications of the nerve model. The agreement between the computations and the earlier experimental results was qualitatively satisfactory. The quantitative agreement was not perfect but the discrepancies were not greater than what is expected from the known errors in the voltage clamp technique. The computations indicated that changes of any of the constants of the nerve model have effects on the rate of accommodation. The greatest effects were obtained by changing the inactivation of the sodium permeability. It was concluded, on the basis of the results obtained in the present and in the earlier investigation, that the slow excitability changes of the nerve fibres are well predicted by the equation system describing the ionic currents. Further, it was concluded that the normal variation in accommodation among myelinated nerve fibres from Xenopus laevis is accounted for mainly by variations in the rate constants ah although this may not be the only variable of importance. A variation in the turning on of the potassium permeability might also be significant.
The Utilization of a Presumably Low‐Cariogenic Carbohydrate Derivative
Authors: Dahlqvist Arne , Telenius Ulf
Published: December 2008

The digestion and absorption of a presumably low‐cariogenic carbohydrate derivative, a hydrogenated partial hydrolyzate of starch, has been studied. This contains free sorbitol, plus disaccharides, oligosaccharides and dextrins in which the glucose molecule which had a free aldehyde group prior to hydrogenation has been reduced to sorbitol. The dextrins present are rapidly hydrolyzed by α‐amylase under the formation of di‐and oligosaccharides. Those disaccharides which are composed only of glucose, are completely hydrolyzed by the intestinal disaccharidases and rapidly utilized in the body. The disaccharides containing one molecule of glucose and one of sorbitol, either initially present as disaccharide or formed on the enzymatic cleavage of the dextrins and oligosaccharides, are very slowly hydrolyzed. The glucose bound in this way largely escapes absorption. The sorbitol, whether free or bound, is very slowly absorbed.
Enzyme Activities in Various Organs of Hypophysectomized Rats and Rabbits
Authors: Jacobsohn Dora , Larsson S. , Norgren A.
Published: December 2008

The activities of nine different enzymes (glucose‐6‐phosphatase, combined activities of glucose‐6‐phosphate dehydrogenase and 6‐phosphogluconate dehydrogenase, phosphohexose isomerase, aldolase, iso‐citric dehydrogenase, lactic dehydrogenase, glutamic‐oxalacetic transaminase, glutamic‐pyruvic transaminase and glutamic acid dehydrogenase) were measured in liver, skeletal muscle, cerebral cortex, hypothalamus, adrenal cortex and thyroid gland of hypophysectomized rats and rabbits. The water and fat contents were determined in liver and muscle. DNA and protein were measured in all tissues. After hypophysectomy the activities of the Embden‐Meyerhof enzymes were unaffected when the values were expressed per unit wet weight or per unit protein. When calculated on unit DNA the activities of almost all enzymes were in most tissues significantly decreased after hypophysectomy. This finding is due to the fact that except for cerebral cortex and hypothalamus in rabbits the DNA content of all tissues studied is significantly increased after hypophysectomy. The observed changes in enzyme activities and DNA content in the tissues are discussed in relation to hormonal and dietary influences on enzyme activities.
The Pattern of Muscular Activity During the Arm Swing of Natural Walking
Authors: Ballesteros Maria L. Fernandez , Buchthal Fritz , Rosenfalck Poul
Published: December 2008

A telemetering device is described to record action potentials from muscles of the upper arm and the shoulder during the arm swing of natural walking. The forward swing is caused by activity in some inward rotators, the flexors remaining inactive. The posterior part of the deltoid and some outward rotators are responsible for the backward swing. During walk‐turning electrical activity occurred in flexors inactive during straight walking accounting for the increased excursion of the forward swing which counteracts the torsional movement of the trunk. Step‐related muscular activity persisted even when the arm was prevented from swinging.
Decrease in Cardiac Activity by Carotid Sinus Baroceptor Reflex
Authors: Lindgren Percy , Manning John
Published: December 2008

Electrical stimulation of the sinus nerve or excitation of the carotid baroceptors by increasing the intrasinus pressure significantly decreased the right ventricular contractile force, heart rate, and blood pressure in 19 anesthetized cats. The decreases in force and rate, but not blood pressure, were abolished by stellate ganglionectomy and by 3–6 mg/kg of dichloroisoproterenol (DCI). The decreases in cardiac contractility and rate were not secondary to the hypotension for they were still obtained when aortic pressure was kept constant. The reductions in contractile force and heart rate are the results of an inhibition of sympathetic control of the heart activity. The data indicates that 40 per cent of contractile force measured in the anesthetixed vagotomized preparation is dependent upon tonic sympathetic impulses. In experiments in which the stellate ganglia were decentralized, the force and rate were increased to predenervation levels by stimulating the isolated right stellate ganglion at a frequency of 1/sec. Seventy‐five per cent of the maximum response in force and rate were obtained at stimulus frequencies of 3/sec. The sinus baroceptor reflex exercises its major effects on the heart and blood vessels within a relatively limited range of 40 mm Hg on either side of normal blood pressure for the cat.
Uptake of Catecholamines by the Hearts of Rabbits Treated with Segontin
Authors: Mackenna B. R.
Published: December 2008

A single i.v. injection of 8 mg/kg of Segontin caused a fall in the NA content of rabbit hearts to less than 10 per cent of their normal value in about 2 hrs. After 4 hrs the tissue content of NA started to rise again and after 24 hrs it had recovered to about one third of its normal value. An i.m. injection of 0.75 mg/kg NA 2 hrs after Segontin treatment, caused a temporary rise in the NA content of the heart to the normal value. NA was increased in the coarse particle fraction, the high speed sediment and in the particle free supernatant fraction of the heart after homogenization, indicating that the exogenous NA is temporarily filling the available storage sites. An i.v. infusion of NA (10 μg/kg/min for 20 min) caused an uptake of NA into the heart previously depleted by Segontin, followed by a rapid and then slower release of the NA. The uptake of 1‐NA and d‐NA and also of 1‐A and d‐A showed stereochemical specificity in favour of the 1‐isomers. Phenoxybenzamine blocked the uptake of NA into the heart of rabbits depleted by Segontin, whereas DCI had only a small blocking effect. Phenoxybenzamine by itself reduced the NA content of all fractions of the heart.
The Potassium Ion as a Vasodilator during Muscular Exercise
Authors: Kjellmer Ingemar
Published: December 2008

Calf muscles of cats were perfused with blood at constant flow rates. Tissue volume, blood flow, arterial and venous pressures were measured. Exercise was imitated by intermittent contractions of the muscles. During contractions the potassium concentration of the venous plasma from the calf increased by up to 100 per cent. Potassium salts infused intra‐arterially at low rates dilated the vessels. It was calculated that the potassium released during exercise directly explains 25 to 65 per cent of the dilatation during exercise, the percentage being smallest when dilatation was slightest. There is presumably a diffusion gradient for potassium between tissue and blood with consequent underestimation of the role of the potassium ions, particularly when the dilatations are only weak. Therefore, 65 per cent probably comes closest to the true value of the proportion of the dilatation due to the potassium ions.

Potassium infusions produced the same vascular response as exercise: a decrease of flow resistance was accompanied by a proportionate increase of the capillary filtration coefficient without signs of any increase in capillary permeability or dilatation of the capacitance vessels. Potassium is the only dilative substance hitherto found to produce exactly the same response as exercise.
In Vitro Glucose Metabolism, in Different Tissues of Hypophysectomized Rabbits
Authors: Jacobsohn Dora , Larsson S. , Norgren A.
Published: December 2008

The effect of hypophysectomy on the fate of uniformly labelled14C glucose was studied in cerebral cortex, anterior and posterior hypothalamus, adrenal cortex and thyroid gland of rabbits. Determinations were also made of DNA content and oxygen consumption of the tissues. The findings after hypophysectomy were as follows: Oxygen uptake of all brain parts increased. The14COSproduction of the posterior hypothalamus was increased. Oxygen consumption and14CO2production decreased in adrenal cortex and thyroid gland. The formation of free14C alanine in the cerebral cortex decreased. The formation of14C aspartic acid in the posterior hypothalamus increased. In the adrenal cortex and thyroid gland a decreased conversion of14C glucose into all metabolites studied was found. The rate of formation of radioactive protein bound amino acids in the brain parts remained unchanged. In the proteins of adrenal cortex and thyroid gland hardly any radioactivity could be detected. The changes appeared to be closely correlated with the activities in various enzyme systems observed previously.
A Comparison of Neural and Psychophysical Responses to Taste Stimuli in Man
Authors: DIAMANT HERMAN , OAKLEY BRUCE , STRÖM LENNART , WELLS CAROLYN , ZOTTERMAN YNGVE
Published: December 2008

Diamant, H. B. Oakley, L. Ström, C. Wells and Y. Zotterman. A comparison of neural and psychophysical responses to taste stimuli in man. Acta physiol. scand. 1965 64. 67–74. – Electrophysiological records of taste activity have been obtained from the chorda tympani nerve of otosclerotic patients. When possible, preoperative psychophysical responses to taste stimuli were also obtained. The summated chorda tympani discharge to 0.2 M NaCl adapts completely and the time required agrees with psychophysical reports. Psychophysical estimates of the sweetness of different sugars correspond closely with nerve response magnitudes. Gymnema extract abolishes both the sweet sensation and the nerve response to sweet tasting chemicals. The total sum of taste activity in the entire chorda tympani nerve appears to be an important determinant of the psychophysical responses. There are large individual differences in the relative size of the neural response to different taste stimuli. Responses to ethyl alcohol are described.
The Urinary Excretion and the Tissue Uptake of Noradrenaline after Severe Tissue Depletion of Noradrenaline by α‐Methyl‐Meta‐Tyrosine and Metaraminol
Authors: ANDÉN NILS‐ERIK
Published: December 2008

Andén, N. ‐E. The urinary excretion and the tissue uptake of noradrenaline after severe tissue depletion of noradrenaline by α‐methyl‐meta‐tyrosine and metaraminol. Acta physiol. scand. 1965. 64. 136–143. Four to eleven hours after an i. v. injection of metaraminol (0.2 mg/kg) to rats pretreated with α‐methyl‐m‐tyrosine (400 mg/kg intraperitoneally on each of the two preceding days) there was a severe reduction of the noradrenaline levels in the sympathetically innervated organs but no significant change in urinary noradrenaline excretion. This finding may indicate that the release of noradrenaline from the sympathetic nerves is unaffected in spite of severe transmitter depletion. The uptake of tritiated noradrenaline from the blood by the sympathetically innervated organs was about 40 per cent of normal after this treatment. Metaraminol (and its precursor α‐methyl‐m‐tyrosine) is almost as efficient as reserpine in causing depletion of the adrenergic transmitter but this effect appears to be due to simple displacement rather than interference with transmitter storage and release.
The Luminal Occlusion Time of Proximal Tubules in Kidneys of Young Rats
Authors: LEYSSAC PAUL P.
Published: December 2008

Leyssac, P. P. The luminal occlusion time of proximal tubules in kidneys of young rats. Acta physiol. scand. 1965. 64. 176–181. – The purpose of this investigation was to test the validity of the luminal occlusion time as a method for estimation of the rate of proximal reabsorption. The occlusion time denotes the time required from interruption of the renal circulation until the proximal tubules have completed reabsorption of the luminal fluid. The results demonstrate that the close correspondance between the rate of reabsorption as evaluated from the occlusion time and the immediately preceding clearance of inulin holds also in experiments with young rats of a body weight of 100 g, in which the volume of luminal fluid per unit tubular length is far less than in kidneys of adult rats.
5‐Hydroxyindoleacetic Acid of Rabbit Spinal Cord Normally and after Transection
Authors: ANDÉN NILS‐ERIK , MAGNUSSON TOR , ROOS BJÖRN‐ERIK , WERDINIUS BENGT
Published: December 2008

Andén, N. ‐E., T. Magnusson, B. ‐E. Roos and B. Werdinius. 5‐Hydroxyindoleacetic acid of rabbit spinal cord normally and after transection. Acta physiol. scand. 1965. 64. 193–196. – The normal spinal cord of rabbits was found to contain 0.20 μg/g 5‐hydroxyindolcacetic acid in the part cranially to Th4–Th6. Caudally the concentration was 71 per cent of that cranially. After transection at this level there was no significant change in the cranial part, when analyzed as a whole. Caudally to the lesion the 5‐hydroxyindoleacetic acid showed a substantial drop during the first 2 days and thereafter a gradual fall. It had disappeared almost completely after 10 days. The 5‐hydroxytryptamine, determined in the same rabbits, was unchanged after 2 days, was considerably reduced after 5 days, and had almost completely disappeared after 10 days. It is concluded that the level of 5‐hydroxyindoleacetic acid better than that of 5‐hydroxytryptamine mirrors the metabolic rate of 5‐hydroxytryptamine.
Direct Studies on the Disappearance of the Transmitter and Changes in the Uptake‐Storage Mechanisms of Degenerating Adrenergic Nerves
Authors: MALMFORS TORBJÖRN , SACHS CHARLOTTE
Published: December 2008

Malmfors, T. and Ch. Sachs.Direct studies on the disappearance of the transmitter and changes in the uptake‐storage mechanisms of degenerating adrenergic nerves. Acta physiol. scand. 1965.64. 211–223. – The histochemical fluorescence method of Falck and Hillarp has been applied to a study of the disappearance of the endogenous noradrenaline (NA) and the uptake‐storage mechanisms of the adrenergic nerves in the rat iris during the course of degeneration following axotomy. It was found that the transmitter stored in the terminals does not disappear gradually but quite suddenly and with various times of onset for the different systems of terminals. The uptake and accumulation of NA and α‐methyl‐NA were examined in untreated and reserpinized animals. These experiments show that the uptake‐storage mechanisms in any given system of terminals operate up to a certain time without any obvious changes, but then deteriorate rapidly, at about the same time as the transmitter stores disappear. The axon membrane reabsorption mechanism seems to be lost somewhat prior to the storage mechanism of the transmitter granules, at the same time as degenerative changes seem to occur in the axon membrane, making possible a passive leakage of NA. – The results add further weight to the view that the cocaine‐like component in the denervation supersensitivity is due to the loss of the uptake mechanisms. – Following the administration of bretylium the degenerative processes were delayed for about 8 hrs.
On the Mechanism for the Stimulating Action of Reserpine on Acid Secretion in Gastric Fistula Cats
Authors: EMÅS SVERRE
Published: December 2008

Emås, S.On the mechanism for the stimulating action of reserpine on acid secretion in gastric fistula cats.Acta physiol. scand. 1965.64. 224–237. –A single intravenous infusion of reserpine, insufficient to reduce antral gastrin activity significantly, elicited acid secretion in nonanesthetized cats with innervated and sympathetically denervated stomachs. Atropine or vagotomy reduced the acid response by 55 to 84 per cent. In vagotomized cats atropine produced a smaller but significant reduction. It was concluded that the vagal and sympathetic nerves are not necessary for reserpine to elicit acid secretion, but that intact vagi and – to a lesser extent – the postganglionic cholinergic neurons of the vagotomized cats enhance the effect of reserpine. Reserpine treatment has previously been shown to sensitize the parietal cells to gastrin, and to cause a transient reduction in antral gastrin activity in nonvagotomized but not in vagotomized cats. In the present study, reserpine treatment reduced the secretory response to intravenous reserpine in nonvagotomized cats and abolished the response in vagotomized cats. A single intravenous infusion of reserpine elicited acid secretion in anesthetized cats after vagotomy and resection of the regions known or suspected to contain gastrin. The results suggest a secretagogue action of reserpine which is not mediated by the vagi and by gastrin.