bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permeability Characteristics of Vascular Smooth Muscle Cells as Revealed by Their Osmotic Responses to Non‐Electrolytes
Authors: Johansson Borje 
Published: December 2008

AbstractChanges of cell volume in the smooth muscle of the isolated rat portal vein, produced by variations in extracellular osmolarity, are associated with characteristic changes in the spontaneous electrical and mechanical activity of the preparation (Johansson and Jonsson 1968, Arvill, Johansson and Jonsson 1969). An analysis of such responses to anisosmotic solutions containing different non‐electrolytes was carried out in the present study in order to elucidate the osmotic influences of the test substances on the vascular smooth muscle cells. The time course of the responses revealed the following relative rates of penetration through the cell membranes: sucrose < erythritol < glycerol < urea < thiourea < ethylene glycol = propylene glycol = tetramethylene glycol = pentamethylene glycol = urethane. The importance of molecular size and lipid solubility for this order of permeability is discussed. A quantitative analysis of responses to solutions containing urea gave an approximate estimation of the osmotic reflexion coefficient for this substance. The value obtained was 0.65 which corresponds to an equivalent pore radius of 3.7 Å. This information and previous data concerning the uptake of urea‐14C by the rat portal vein could be used for a calculation of the total pore area. The result indicated that the pores occupy only a very small fraction, 7 × 10–7, of the total area of the cell membrane and that the number of pores is of the order of 103 per cell or 1.6 × 103 per cm2.
Effect of Acid in the Duodenal Bulb on Gastric Secretory Responses to Sham Feeding1
Authors: Nilsson Göran 
Published: December 2008

AbstractGastric secretion was stimulated by sham feeding in Pavlov pouch dogs with esophageal fistulae and isolated pouches of the duodenal bulb. Reduction of the intrabulbar pH to pH 3–4 inhibited the acid response to sham feeding. Bulbar acidification was more effective in inhibiting acid responses to 1 and 10 min of sham feeding than responses to 30 min of sham feeding. Short periods of bulbar acidification were sufficient to activate the bulbar inhibitory mechanism.
Uptake and Distribution of Rubidium‐86 and Potassium‐43 in Mice and Rats—an Autoradiographic Study
Authors: Olsson Kurt A. , Söremark Rune , Wing Kenneth R. 
Published: December 2008

AbstractThe uptake and distribution in mice of rubidium‐86 (86Rb) and potassium‐43 (43K) was studied using whole body autoradiographic techniques. In addition, a microautoradiographic study of the distribution of 86Rb in the heads of rats was made. The results demonstrate high relative accumulation of 86Rb in hyaline and articular cartilage, tendon, forming bone, liver, pancreas, salivary glands, thymus, spleen and skeletal muscle. At one hour post‐injection, the distribution pattern of 43SK was similar to but much less differentiated than that of 86Rb. Relatke to the accumulation of each in skeletal muscle, 86Rb was more concentrated than 43K in hyaline and articular cartilage, tendon and liver, while the converse was seen in heart muscle, lung, bone and brain. The micro‐autoradiograms demonstrated high relative uptake of 86Rb in trahecular bone and the dentin and enamel of unerupted teeth. The results of the present study have been compared to those of previously published quantitative studies on the accumulation of 86Rb and 42K, and the results were found to be in close agreement. In addition, the present results demonstrate high relative accumulation of 86Rh and 48SK in hyaline and articular cartilage, tendon and forming bone, and high 86Rb concentrations in forming teeth and foetal bone and cartilage, observations which hale not been made in earlier studies. The similarities to and differences from the results of a similar study of the uptake and distribution of caesium‐137 (137Cs) are discussed.
Hair Discs and Pacinian Corpuscles Functionally Associated with the Carpal Tactile Hairs in the Cat
Authors: Nilsson Bengt Y. 
Published: December 2008

AbstractA hair disc containing Merkel cell‐neurite complexes at the base of the epidermis lateral to each carpal sinus hair in the cat is demonstrated. The physiological properties of these receptors and of the Pacinian corpuscles around the sinus hair root were analyzed using electro‐physiological techniques and a mechanical stimulator permitting displacements at different rates and amplitudes. The hair disc receptor could be excited by direct mechanical stimuli and by lateral deflection of the hair. The dynamic response was displacement‐rate sensitive. The slowly adapting static response was related to the displacement amplitude. The Pacinian corpuscles followed a sinusoidal skin stimulation from 20 c/s to 300–400 cis. A plot of the lowest amplitude giving one imp/cycle at different frequencies gave a U‐shaped curve with lowest threshold at 125–250 c/s. These receptors were also sensitive to vibratory stimulation of the hairs; on rapid hair displacement on and off responses resulted. An example is given of simultaneous activation of slowly adapting hair receptors and Pacinian corpuscles by displacement of a hair. The functional significance of the unique combination of four different types of mechanoreceptor in “the tactile hair organ” is discussed.
Respiratory Sensitivity to Acute Hypoxia in Goat Kids Born at High Altitude
Authors: Mines Allan H. , Sørensen Søren C. 
Published: December 2008

AbstractIn human infants, chronic hypoxia irreversibly desensitizes the peripheral chemoreceptor respiratory response to acute hypoxia. We attempted to desensitize 2 goat kids conceived at sea level, delivered after 1 to 3 weeks at 3100 m altitude, and transferred to 3800 m at 6 weeks of age. The kids were brought to sea level when 14 weeks old. The respiratory response to GO, at two levels of oxygen tension was determined 6 to 8 weeks later. The slope of the CO2‐response curve at high PO2 (200 mm Hg) and the change in slope and fall in PCO2 intercept produced by hypoxia (PAO2= 40 mm Hg) resembled those of normal adult goats, indicating no permanent desensitization.
Mast Cells and 5‐HT. Intracellular Release of 5‐Hydroxytryptamine (5‐HT) from Storage Granules during Anaphylaxis or Treatment with Compound 48/80
Authors: Carlsson S.‐A. , Ritzén M. 
Published: December 2008

AbstractThe release of 5‐hydroxytryptamine (5‐HT) and granules from peritoneal mast cells during in vitro and in vivo anaphylaxis and after treatment with compound 48/80 in vitro was investigated by quantitative cytochemical methods. Sensitization was achieved by s.c. injections of horse serum with H. pertussis, and anaphylaxis was observed 3–30 weeks later. The 5‐HT content of mast cells was assayed by microfluorimetry, the cellular content of granules by microinterferometric measurements of cellular dry mass. Incubation of peritoneal mast cells with antigen in vitro resulted in release of 7–32% of 5‐HT, compared to 20–50% release following i.v. injection of specific antigen to the same rat. Incubation of non‐sensitized mast cells with compound 48/80 (1.6 μg/ml) caused a release of 45% of the 5‐HT. Microfluorimetric and microinterferometric measurements of the same individual mast cells revealed a proportionally greater release of 5‐HT than lowering of dry mass values. Since only a small part of the cytoplasmic dry mass is non‐granular material, the results indicate that under the present experimental conditions about 40% of the total 5‐HT release was not accompanied by a simultaneous extrusion of granules. It could also be demonstrated by fluorescence microscopy that a varying proportion of the granules had released their 5‐HT while still intracellularly located. This demonstration of intracelular release of 5‐HT from storage granules may be relevant also for other types of secretory cells.
Histochemical Characterization of a Tryptamine‐Like Substance Stored in Cells of the Mammalian Adenohypophysis
Authors: Björklund Anders , Falck Bengt 
Published: December 2008

AbstractA recently developed, sensitive fluorescence method for the histochemical localization and the microspectrofluorimetric characterization of tryptamine (Björklund, Falck and HBkanson 1968) has been applied to the pituitary gland of the rat, cat, and pig. In all three species, most of the cells of the pars intermedia and many cells in the pars distalis were found to store a substance in the cytoplasm that could be transformed to a highly fluorescent derivative under the special reaction conditions required to obtain a high fluorescence yield of tryptamine. This pituitary fluorophore, moreover, showed the same microspectrofluorimetric characteristics under various conditions as does the tryptamine fluorophore. These histochemical and microspectrofluorimetrc characteristics differ clearly from those exhibited by a number of catechol and indole compounds, including the biogenic catecholamines, 5‐hydroxytryptamine and tryptophan. The reliability and the significance of the histochemical criteria are discussed, and it is concluded that there is much to support the view that tryptamine, or a closely related β(3–1ndolyl)ethylamine, is stored in the adenohypophysis. Another fluorophore that may derive from a hitherto unknown biogenic phenylethylamine was disclosed in a large number of pars distalis cells not identical with those that possibly store tryptamine.
The Influence of DOPA on the Static and the Dynamic Fusimotor Activity to the Triceps Surae of the Spinal Cat
Authors: Grillner S. 
Published: December 2008

AbstractThe influence of descending “noradrenergic” fibres on the stretch reflex and the discharge of γ‐motoneurones to the triceps surae has been analysed by injecting DOPA i.v. in the acute spinal unanesthetized cat. After DOPA, a tonic stretch reflex develops in the soleus muscle as revealed by an increased electromyographical activity on extension of the muscle. In parallel, static γ‐motoneurones aqcuire a resting discharge, which can be inferred from the finding that secondary endings have an elevated discharge rate after DOPA. The discharge in single γ‐efferents could be influenced through short latency reflex paths from afferent fibres including group II afferents; further, the γ‐efferents were found to participate in the late and long‐lasting reflex effects that can be evoked after DOPA. On the basis of their resting discharge and reflex effects, the γ‐efferents recorded could tentatively be identified as static or dynamic. Both static and dynamic γ‐motoneurones to extensors have a higher resting discharge after DOPA. Hence in contrast to previous findings on flexor γ‐motoneurones no reciprocal control on the resting discharge in the two types of efferents is exerted. Only γ‐motoneurones classified as static received monosynaptic activation from fast descending fibres, presumably vestihulospinal.
Intracellular Potentials of the Corneal Epithelium
Authors: Ehlers Niels 
Published: December 2008

AbstractEhlers, N. Intracellular potentials of the corneal epithelium. Acta physiol. scand. 1970. 78. 471–477.The potential and resistance profiles through the rabbit and cat corneal epithelium were studied by means of microelectrodes. Negative intracellular potentials were recorded in all experiments. A transepithelial potential difference was regularly found only in rabbits, the inside being 10–15 mV positive in relation to the outside. Positively directed peaks were recorded inside the epithelium, which reached but never exceeded the level of the inside potential. The number of these peaks increased when epithelial oedema was produced by increasing the transcorneal hydrostatic pressure difference. In consequence, the peaks are believed to represent intercellular spaces. The electrode resistance was measured continuously and simultaneous with the potential. During penetration of the cytoplasm the resistance was about twice as high as in the bathing fluid, it increased further when cellular membranes were punctured, and especially when the basement membrane was penetrated.
Characteristics of Receptors and Afferent Fibres of the Forelimb Interosseous Nerve of the Cat
Authors: Silfvenius H. 
Published: December 2008

AbstractSilfvenius, H. Characteristics of receptors and afferent fibres of the forelimb interosseous nerve of the cat. Acta physiol. scand. 1970. 79. 6–23.A description is given for dissection and identification of the forelimb interosseous nerve, Int. f., a branch of the median nerve. The nerve contained on average 225 axons. The measured diameters of the myelinated axons of the Int. f. ranged between 1 and 16 μ. A bimodal distribution of fibres was found, with peaks around 4 μ and 10 μ. The fibres of the low threshold main component of the compound action potential conducted at velocities between 85 and 110 m per sec. The properties of receptors and afferent fibres were studied in 52 single fibres of the median nerve. About 50 per cent of these were rapidly adapting, the others slowly adapting. Among the rapidly adapting, 33 per cent were low threshold vibration sensitive Pacinian receptors whose fibres conducted at velocities between 63 and 117m per sec. The remaining 15 per cent were identified as high threshold tap receptors, some of which were vibration sensitive. Their fibres conducted at velocities between 27 and 118 m per sec. 36 per cent of the slowly adapting units were tension receptors with fibres conducting at velocities between 27 and 110 m per sec. The other group (12 per cent) consisted of muscle spindles. They conducted at velocities between 85 and 110 m per sec. About 4 per cent of the population remained unidentified. Functional aspects of the findings are discussed.
Pregnancy in Exercised and Food Restricted Goldthioglucose Obese Mice
Authors: Einer‐Jensen N. , Larsson S. , Nielsen P. Alstrup , Secher N. J. 
Published: December 2008

AbstractEiner‐Jensen, N., S. Larsson, P. Alstrup Nielsen and N. J. Secher. Pregnancy in exercised and food restricted goldthioglucose obese mice. Acta physiol. scand. 1970. 79. 5a‐63.NMRI/BOM mice made obese with goldthioglucose were studied with respect to the influence of forced muscular exercise and food restriction upon fertility. The obese mice were found to be sterile. Only minor disturbances were observed in the vaginal smears. After exercise and food restriction resulting in pronounced decrease in weight they became fertile and gave birth to normal litten.
Effect of Nicotinic Acid on ACTH and Noradrenaline Stimulated Lipolysis in the Rabbit. I. In Vivo Studies
Authors: Boberg Jonas , Micheli Horace , Rammer Lennart 
Published: December 2008

AbstractACTH, 50, 10, 2 and 0.5 IU/kg b.w. and noradrenaline, 1.0 μg/kg/min were given i.v. to fed, unanesthetized rabbits either pretreated with nicotinic acid or not.Both ACTH and noradrenaline increased arterial concentration of free fatty acids (FFA). For noradrenaline this effect was present only in rabbits with lower body weight and furthermore the effect was less pronounced and of shorter duration than for ACTH.Nicotinic acid inhibited partly the increase of plasma FFA caused by 0.5 IU of ACTH but not that after the higher doses. Nicotinic acid had sometimes but not always an inhibitory effect on the increase caused by noradrenaline while nicotinic acid by itself did not change the basal levels of plasma FFA.
Effect of Nicotinic Acid on ACTH and Noradrenaline Stimulated Lipolysis in the Rabbit. II. In Vitro Studies Including Comparison with Prostaglandin E1
Authors: Boberg Jonas , Micheli Horace , Rammer Lennart 
Published: December 2008

AbstractPerirenal adipose tissue from male rabbits was inrubated in vitro and the glycerol release followed as a measure of lipolysis. Addition of nicotinic acid to the medium did not change the basal release. Nicotinic acid inhibited the noradrenaline stimulated lipolysis only in 3 of 8 rabbits, while PGE, under the same conditions was inhibitory in 6 of 6 rabbits. Nicotinic acid only inhibited lipolysis stimulated by ACTH at low doses in one of seven experiments. In comparison to PGE, nicotinic acid was found to be a weaker inhibitor of lipolysis in rabbit adipose tissue stimulated in various ways in vitro. These findings suggest that the previously seen weak properties of nicotinic acid as a FFA lowering compound in rabbits may be explained by factors within adipose tissue.
Autoradiographic Studies with 35S‐Sulfate on Somatotrophin and Estrogen Sensitivite Growth Zones in Rat and Mouse Costal Cartilage
Authors: Herbai Georg 
Published: December 2008

AbstractAn autoratliographic study was performed on the regional pattern of incorporation of 35S sulfate in different anatomical regions of costal cartilage in growing mice and rats in uivo and in vitro. Profound regional differences in sulfate incorporation rate have been revealed between the medial or “resting” part of costal cartilage and the “active” growing region of the rib which is located in close association with the osteochondral junction. The regional pattern of sulfation activity showed great similarities in the rib cages of rats and mice. The increased sulfate incorporation activity in the growth region of mouse rib cartilage was also maintained when the rib cage was incubated in vitro with 35S‐sulfate. Hypophysectoniy almost completely abolished, and somatotrophin treatment of hypophysectomized mice with 500 μg GH‐NIH‐S8 for 10 days restored the rate of sulfate uptake to above normal levels in the growth zones of the ribs. A 10 clay treatment with a daily dose of 100 μg estradiol Iienzoate per mouse caused a pronounced fall in the sulfate incorporating activity of the growth region and markedly narrowed the “active” zone of the costal cartilage.
Inhibition of Thromboplastin‐Induced Intravascular Coagulation by Heparin and Trasylol
Authors: Nordström Sam 
Published: December 2008

AbstractHomologous brain thromboplastin was injected or infused in different ways in dogs, and various coagulation factors were followed for 7 days. Slow infusions of thromboplastin in anesthetized dogs caused changes in platelet count and fibrinogen concentration similar to those usually seen in the postoperative period in man. The heparin co‐factor decreased only slightly, which is contrary to the postoperative reactions in both man and dogs.The decrease in platelet count and fibrinogen concentration and the rate of thromboemboli after intravenous thromboplastin administration could partly be inhibited, if the dogs were treated prophylactically with Trasylol, and completely inhibited, if they were pretreated with heparin. Trasylol also seemed to exert some slight influence on the antithrombin level in the circulating blood. The in vivo anticoagulant effect of Trasylol might be the result of partial inhibition of more than one reaction in the coagulation process. Compared to heparin Trasylol is a weak anticoagulant.
Contraction Times and Fibre Types in Intact Human Muscle
Authors: Buchthal Fritz , Schmalbruch Henning 
Published: December 2008

AbstractTwitches were recorded in situ in muscles of normal humans by small transducers connected to a needle in the tendon. The twitches were elicited by stimuli in the endplate zone, the force of the smallest twitches corresponding to the average of one or two motor units. The time to peak contraction was measured of 20–30 bundles of fibres in each muscle examined. The histograms of contraction times agreed with histochemical findings; contraction times longer than 60 msec corresponded to the proportion of fibres rich in mitochondria. Thus, long contraction times predominated in the soleus and gastrocnemius muscles, comprised half the times in the anterior tibia], a third in the brachial biceps (long head) and a few per cent in the brachial triceps muscle (lateral head). Bundles of fibres with short contraction times, those poor in mitochondria had a higher temperature coefficient of the time to peak than bundles with long contraction times. During hypoxia the contraction times shortened. The contraction time of motor units first activated voluntarily lay near the mean of bundles activated electrically. The contraction times of fasciculating fibres were in the range of electrically evoked twitches; the force was about three times that of voluntarily activated units.
Sodium Transport and D.C. Resistance in the Isolated Toad Skin in Relation to Shedding of the Stratum Corneum
Authors: Larsen Erik Hviid 
Published: December 2008

AbstractIt has been assumed that the main resistance to sodium ion movements is located in the superficial layer of the amphibian skin. It is therefore of interest to follow transport function during shedding of the stratum corncum. Shedding of the stratum corneum in the isolated toad skin (Bufo bufo) can be induced by aldosterone treatment of skin from hypophysectornized toads. It is shown that slough formation is followed by an almost three fold increase in short‐circuit current. This increase is accounted for by an increased rate of active sodium transport and is preceded by an increase in passive sodium permeability and a decrease in D.C. resistance. The results are discussed in relation to the functional organization of the skin, and to moulting in vivo.
Effect of Trasylol on Thromboplastin‐Induced Arterial Hypotension
Authors: Nordström Sam 
Published: December 2008

AbstractThe effect on arterial blood pressure of pretreatment with Trasylol was studied in dogs injected i.v. with homologous brain thromboplastin. Trasylol did not consistently inhibit the initial fall in arterial blood pressure, but the return to normal pressure level was faster after administration of the drug. This effect of Trasylol might depend on interference with coagulation processes as well as with release of vasoactive substances.
Effects of Reptilase‐Induced Intravascular Coagulation in Dogs
Authors: Egberg Nils , Nordström Sam 
Published: December 2008

AbstractThe effect of the thrombin‐like enzyme preparation Reptilase, purified from the venom of the snake Bothrops atrox, was studied in dogs injected with 125I‐labelled fibrinogen. Reptilase was capable of inducing intravascular coagulation as shown by the decrease in fibrinogen concentration, but influenced the platelet count only moderately. No bleeding tendency was observed. Pretreatment with heparin did not affect the defibrination process. Secondary activation of the fibrinolytic system was demonstrated by the appearance in plasma and serum of fibrinogen degradation products, studied by radioactivity measurements and immunological methods. Epsilon anunocaproic acid (EACA) and Trasylol could reduce and delay but not completely abolish the secondary fibrinolysis. No thromboemboli were found at autopsy.In long‐term treatment by daily injections of Reptilase it was possible to keep the fibrinogen concentration at low levels for several weeks without adverse effects. The hemostatic function was maintained undisturbed probably due to the fact that the platelet count was essentially unchanged.
Release and Uptake of Dopamine in Isolated Granules from a Human Carotid Body Tumour
Authors: Lishajko F. 
Published: December 2008

AbstractIsolated granules from a human carotid body tumour incubated in 130 mM K‐phosphate pH 7.5 release dopamine (DA) with a half time of 23 min at 37° C. Addition of DA 2times10‐5M to the incubation fluid prevents net loss of DA from the granules, owing to reuptake. Further addition of ATP‐Mg2+increases the DA content in the granules about 8 times. This effect is strongly inhibited by reserpine 10‐3M and reduced about 40 per cent by noradrenaline (NA) and adrenaline (A) each in a concentration of 10‐5M.