bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Tissue Distribution of 3H‐Terbutaline (Bricanyl®) in Mice
Authors: Bodin N. O. , Hansson E. , Ramsay C. H. , Ryrfeldt Å. 
Published: December 2008

AbstractThe tissue distribution of 3H‐terbutaline. a new β‐stimulaing tagent, was investigated in mice by whole‐body autoradiography as well as by determinations of unchanged and biotransformed terbutaline in serum, lung, heart, and liver.The radioactivity was localized mainly to the extracellular space and the levels in most tissues were of the same magnitude as that in blood; no uptake and storage of the drug was observed. Neither terbutaline nor its metabolites penetrated the blood‐brain barrier or the placenta barrier. High relative concentrations of unchanged drug were found in the tissues studied, especially in the lung. A low rate of biotransformation is considered to be the cause for this.
The Volume Responses of Various Vascular Beds to a General Blood Loss. A Study Carried out in Rats Exposed to Two Different Procedures of Anesthesia
Authors: Aarseth P. , Piene H. 
Published: December 2008

AbstractSeveral vascular compartments have been claimed to have marked blood depot functions. In the present experiments an attempt has been made to compare different vascular beds of the rat in this respect, by evaluating the tissue blood content in bled and non‐bled animals. Erythrocytes and plasma‐albumin were labelled by radioisotopes, and the whole rat was then immersed in liquid nitrogen. The lungs, the heart with the thoracic vessels, the splanchnic organs and samples from skeletal muscles were then removed and their content of radioisotopes estimated. In animals anesthetized intraperitoneally with pentobarbitone the pulmonary blood volume and the skeletal muscle blood content were markedly reduced after a blood loss of 12 % When, however, the animals were anesthetized by ether‐inhalation, and by a subsequent small dose of pentobarbitone i.v., then a similar bleeding caused a marked reduction in the splanchnic blood volume, but almost no reduction in the pulmonary blood volume or the skeletal muscle blood content.
Effect of Brain Lesions and Chlorpromazine on Accumulation and Disappearance of Catecholamines Formed in vivo from14C‐Tyrosine
Authors: Nybäck Henrik 
Published: December 2008

AbstractRats were subjected to a unilateral stereotaxic lesion at the level of the mesencephalic‐hypothalamic junction where the nigro‐striatal dopamine (DA) pathway is known to pass. Between 6 and 18 h after the lesion the level of DA in the striatum on the same side was increased by about 50 per cent. Between 18 and 48 h after the lesion the content of DA declined to 15 per cent of that of the contralateral striatum and stayed at this low level during the following 6 days. The content of noradrenaline (NA) tended to be increased 24 h after the lesion but no change was found on the following days. The accumulation and disappearance of14C‐DA formed from14C‐tyrosine in the striatum 12–24 h after the nigral lesion were decreased on the lesion side in comparison with the contralateral side. The accumulation and disappearance of14C‐NA did not differ between the 2 sides. Chlorpromazine accelerated both accumulation and disappearance of14C‐DA in the striatum on the side contralateral to the lesion but not in the striatum of the lesion side. In animals with a unilateral lesion above the DA pathway, in the posterior thalamus, chlorpromazine accelerated the accumulation of14C‐DA on both sides. The accumulation of14C‐XA in the striatum was increased by chlorpromazine on the intact side following both types of lesions. The disappearance of14C‐NA, however, was not influenced by the drug. The results are taken as evidence that chlorpromazine accelerates DA turnover in the striatum by activating the nerve impulse flow in the nigro‐striatal DA pathway.
Splenic Blood Flow in the Guinea‐Pig Measured with Xenon 133, and Calculation of the Venous Output of Lymphocytes from the Spleen
Authors: Sandberg Göran 
Published: December 2008

AbstractSplenic blood flow was measured in normal guinea‐pigs of three weight classes, and in groups immunized with pertussis vaccine or sheep erythrocytes (SRBC). The determination was based on the wash‐out of xenon 133 injected directly into the splenic tissue.In the normal guinea‐pigs the blood flow in ml/g min decreased slightly with weight, the means in the three weight classes being 0.85, 0.73 and 0.66 ml/g min. After injection of pertussis vaccine the splenic blood flow was significantly greater in relation to the weight of splenic tissue than for the controls given a saline injection, but the flow was unaffected by immunization with sheep erythrocytes.Combination of the blood flow values with the differences in lymphocyte content between splenic efferent and afferent blood made it possible to calculate the splenic release into the blood of lymphocytes formed in the spleen. This increased with body weight, and in the heaviest animals reached about 10o cells/24 h. In the animals injected with pertussis vaccine the number of lymphocytes released was significantly greater than in the corresponding controls. An increase recorded after immunization with sheep erythrocytes was, however, not statistically significant.
Effect of Nerve Stimulation In Vitro on the Noradrenaline Content of the Rat Vas Deferens in the Presence of Inhibitors of Noradrenaline Uptake and Synthesis
Authors: Swedin Göran 
Published: December 2008

AbstractIsolated rat vas deferens preparations were intermittently field stimulated (30 s every min) for 2 or 4 h at 7 or 25 imp/s. At the low stimulation frequency only a very small reduction (7 %) of the endogenous noradrenaline (NA) stores was seen during 4 h stimulation while it was about 15%after 2 h and 37%after 4 h at 25 imp/s. Addition of drugs known to inhibit NA synthesis (a‐methyl‐p‐tyrosine, a‐MPT, 4times10‐4M) or uptake (cocaine, 10‐5M) did not apparently influence neither the spontaneous nor *the nerve‐induced reduction of the endogenous NA stores. The present results seem to support the hypothesis that the functional transmitter pool of the short adrenergic neurons of the vas deferens is very small, and that the residual NA reuptake and synthesis after pharmacological blockade, together with minute refilling from the large storage pools, are able to maintain transmitter homeostasis without significant changes of the total endogenous NA content of the vas deferens.
The Distribution of Xe‐133 in the Left and Right Ventricular Walls of Dog Hearts after Left Ventricular Bolus Injection
Authors: Bagger Henning 
Published: December 2008

AbstractBagger, H. The distribution of Xe‐133 in the left and right ventricular walls of dog hearts after left ventricular bolus injection. Acta physiol. scand. 1972. 84. 275– 283.Regional coronary blood flow was estimated in dogs by counting the activity in tissue blocks of the left and right ventricular walls after bolus injection of Xe‐133 into the left ventricular cavity.Myocardial uptake of the isotope was 1.7 times higher in the left than in the right ventricular wall, while comparison of the activities in the subepicardial half of the walls showed a ratio left/right of 1.5.The transport through the endocardial surface of the left ventricular wall was measured during constriction of the left coronary artery. Xe‐133 penetrates to a depth of 7 mm, indicating that transport across the endocardial surface might contribute to the activity of the subendocardial half of the wall.In the left ventricle the activity was higher (15 %) in the subendo‐ than subepicardial half of the wall, but in view of the transport across the endocardial surface, the amounts of xenon transported by the coronary arteries seem to be equal, indicating a uniform perfusion of the left ventricular wall. No differences appeared either between areas supplied by the anterior descending and circumflex branches of the left coronary artery or between the apex and the base.In the right ventricular wall there was no difference between subepi‐ and subendocardial activity.
Circulatory Control via Vagal Afferents
Authors: Gastenfors Jan , Knutsson Evert , Sjöstrand Torgny 
Published: December 2008

AbstractCastenfors, J., E. Knutssonand T. Sjöstrand. Circulatory control via vagal afferents. II. Effects of hemorrhage on afferent discharges via the laryngeal communicans in the rat. Acta physiol. scand. 1972. 84. 355–365.Recordings were made of afferent impulses passing through the communicating branch between the superior and inferior laryngeal nerves and in the recurrent nerve after section of the vagus. Two types of discharges varying with changes of the blood volume were recorded.1. Continuous nerve impulses which are increased in frequency on hemorrhage.2. Repetitive burst of spikes with a heart rhythm which starts at the first heart sound, proceeds until shortly after the P wave and ceases with the IV sound. This activity appears to correspond to the inflow of blood to the heart. On hemorrhage the activity diminishes and disappears entirely after a given loss of blood, returning on reinfusion.The slowing of the heart rate on hemorrhage, described in the preceding paper, is assumed to be a result of an increase of the impulse flow through the laryngeal communicans. It is also assumed that the allied receptors are located on the low‐pressure side. The receptors firing synchronously with the heart rhythm are assumed to belong to the earlier described group of atrial receptors of type B. Their function is postulated to be opposite to that of the former receptors, thus increasing the heart rate with increasing central blood volume.
The Role of CI‐ and other Anions in Active Na+ Transport in Isolated Frog Skin
Authors: Huf ErnstG. 
Published: December 2008

AbstractHuf, E. G. The role of CI and other anions in active Na* transport in isolated frog skin. Acta physiol. scand. 1972. 84. 366–381.Skins of several amphibian species were kept between hemi‐chambers in solutions of identical SO42 Ringers' solutions with, or without mannito! (SM, S). When steady state was reached the SO‐i2˜ ions were replaced by equivalent amounts of one of the following anions (A): Cl−, HCO3k, NO3. Replacements were made in sequence, on the outside (o), the inside (i), and both sides of the skin, with periods of SO42 solutions on both sides between the several phases. In other experiments skin pairs were set up for simultaneous Na 24 and CI35 influx and out‐flux measurements. In all experiments, measurements on short circuit current (SCC) and open skin PD (E) were made, and from this total skin conductance (GT) data were calculated, as were values for E\a and Gaxa‐ From these data it is concluded that CI; (with SM0) leads to stimulation of Na* influx and net Na* flux resulting from epithelial swelling; increase in SCC; E; GT; E\a Gaxa‐The order of effectiveness of Af on electrical parameters was Cl− > NO3 > HCO3. Cl0 (with Clf) resulted in: a) “shunting” of Exa; b) depression of Na* influx, of SCC, E, Exa, G\\a; c) Cl0 (with SMj) seemed to stimulate Na* influx, but the flux data were as yet inconclusive. There were marked skin species differences. Best recoveries of starting values were obtained with skins of R. esculenta. Increases or decreases in Na* influx did not correlate with changes in Na* outflux, Cl− influx and Cl− outflux. Possible sites of A”‐membrane interactions involving the Na* transport system are discussed. Work by others is confirmed that in skins of R. esculenta, bathed in SO‐12 Ringer's with 4 mM Cl−, Cl− is actively transported in the inward direction at a level of approximately 109rof the active inward Na* transport.
Influence of Plasma Hypertonicity on Blood Viscosity Studied in Vitro and in an Isolated Vascular Bed
Authors: Rasmussen Sven Nybo 
Published: December 2008

AbstractThe effects of plasma hypertonicity on blood viscosity have been examined in vitro as well as in a vascular bed. NaCl was added to ox‐blood to produce plasma osmolalities up to about 1000 mosm/kg. The isolated rabbit ear was perfused at 70 and 30 mm Hg. Apparent viscosities of blood relative to plasma were calculated from the corresponding flow ratios (‘in vivo’ viscosity). Relative viscosities in vitro of the perfusates were determined by means of a cone‐plate viscometer. Blood viscosity measured ‘in vivo’ as well as in vitro was significantly increased by increasing osmolality. Maximal increments (almost 100 per cent) were observed between 700 and 900 mosm/kg. Plasma viscosity and vascular resistance was not influenced by hypertonicity. Viscosities ‘in vivo’ were generally lower than in vitro–the discrepancy was more pronounced at 70 than at 30 mm Hg and was greater in isotonic than in hypertonic blood. The effect of hypertonicity on blood viscosity is explained mainly by a reduced deformability of the hypertonically crenated red cells. It seems likely to explain the inverse relationship between renal medullary blood flow and medullary hypertonicity (Thurau et al. 1960) as caused partly by passive mechanisms involving blood viscosity changes with varying osmolality.
Proton‐ and Carbamino‐linked Oxygen Affinity of Normal Human Blood
Authors: Garby L. , Robert M. , Zaar B. 
Published: December 2008

AbstractThe oxygen affinity of normal human blood was measured at two different pH values and three different pCO2 values over the whole saturation range. From these data, and from data on the interaction of 2,3‐diphosphoglycerate with hemoglobin, values were calculated for the proton‐linked oxygen affinity at different pCO2 values and for the carbamino‐linked oxygen affinity at different pH values. Both the proton‐linked and the carbamino‐linked oxygen affinity were found to be markedly dependent on the degree of oxygen saturation. The relative contribution of the three ligands, i.e. protons, carbon dioxide and 2,3‐diphosphoglycerate, to the classical Bohr effect was estimated and found to be dependant on the oxygen saturation level. The values for the proton‐linked oxygen affinity and the carbamino‐linked oxygen affinity were found, by applications of Wyman's reciprocal relations and 2,3‐diphosphoglycerate binding data, to give good estimates of the oxygen‐linked proton binding and the oxygen‐linked carbamino binding. The data show that the oxygen‐linked carbamino reaction takes place mainly during the binding of the first 2 oxygen molecules with a value of about 0.25 mol per mol of oxygen. The proton release accompanying this reaction was estimated to be 1.3–1.7 mol per mol.
Bretylium and the Supersensitivity to Exogenous Noradrenaline after Sympathetic Denervation Studied in the Conscious Rat
Authors: Lundberg Dag 
Published: December 2008

AbstractRats denervated by excision of the superior cervical sympathetic ganglion and given reserpine at the time of operation were used. The width of the palpebral aperture, which reflects the tone of the sympathetically innervated periorbital smooth muscle, was measured in the conscious rats after differenti.p.doses of 1‐noradrenaline. The sensitivity of the muscle to exogenous noradrenaline was thus tested during 3 periods of 3 h duration each between 13 and 30 h after denervation. Bretylium, which is known to delay the degeneration contraction of the muscle,i.e.the degeneration transmitter release, postponed the development of denervation supersensitivity. Hence, bretylium seems to preserve temporarily both the amine storage mechanisms and the axonal amine pump in the degenerating adrenergic nerve terminals.
Prostaglandin Induced Inhibition of Neurotransmission in the Isolated Guinea Pig Seminal Vesicle
Authors: Hedqvist Per 
Published: December 2008

AbstractThe contractile response of the guinea pig seminal vesicle to postganglionic nerve stimulation is inhibited by prostaglandin Ei and E2 in low doses and potentiated by high doses. Prostaglandin Ei and E2 consistently increase the contractile response to exogenous noradrenaline. The potentiation by high doses of prostaglandin Ei of the effector response to nerye stimulation is antagonized by SC 19220, inhibitor of prostaglandin action. The effect of prostaglandin Ei and E2 on the neuroeffector system of the seminal vesicle may be explained by a dual action, inhibition of noradrenaline release from the nerve terminals and potentiation of the effector response to the noradrenaline released. An endogenous prostaglandin‐mediated regulation of the smooth muscle response to nerve activity is suggested.
Influence of Extracellular Calcium on Isometric Force and Velocity of Shortening in Depolarized Venous Smooth Muscle
Authors: Hellstrand Per , Johansson Borje , Ringberg Anita 
Published: December 2008

AbstractThe Ca++ dependence of the contracture response obtained in depolarized smooth muscle from rat portal vein was studied. Double reciprocal plots of isometric force versus [Ca++]n were examined by linear regression analysis for n = 1, 2 and 3. The data were consistent with a linear relationship for n = 2. This may be taken to indicate that isometric force is regulated by the binding of two calcium ions to an unknown “receptor compound” in the tissue. In other experiments the velocity of shortening was studied by the method of quick release after the muscles had developed isometric contractures in 2.5 or 0.4 mM [Ca++]0, respectively. The mean isometric forces elicited by these 2 levels of [Ca++]0 differed by a factor of 1.7, but the shortening velocities at comparable relative loads were essentially the same. These results may be considered in the light of recent studies of striated muscle which have been concerned with the problem whether Ca++ determines exclusively the number of activated cross bridges in the sliding filament system or whether it also influences the rate of movement of the individual cross bridge.
Catecholamine Storing Cells in Human Fetal Superior Cervical Ganglion
Authors: Hervonen A. , Kanerva L. 
Published: December 2008

AbstractThe distribution and structure of small, intensively fluorescent, granule‐containing cells within the human feta! ganglion cenicale superius was studied. The ganglia contained numerous small collections of these cells evenly scattered over the whole region of the organ. The granule‐containing cells were as a rule located on the capillaries and showed regularly tight contacts with the basement membrane. The mean diameter of the catecholamine storing granules was 2700 A. The differentiation and role of the granule‐containing cells within sympathetic nervous system was discussed.
Assay of the Transformation of Collagen in situ
Authors: Heikkinen E. , Ivaska K. , Kulonen E. 
Published: December 2008

AbstractSkin extract of newborn rats increases the insolubilization of collagen in skin slices in vitro. The effect is destroyed by heating and inhibited by lathyrogens. Purified collagen in the precipitated form is. on the contrary, transformed to the more soluble forms by skin extract.
Properties of Cortical Group I Neurones Located in the Lower Bank of the Anterior Suprasylvian Sulcus of the Cat
Authors: Silfvenius H. 
Published: December 2008

AbstractRecordings were made from 134 cortical cells of the forelimb group I locus in the lower bank of the anterior suprasylvian sulcus in chloralose anesthetized cats. The cells were studied with regard to their connexions with group I and II muscle‐, skin‐ and joint afferents in the contralateral limbs and with auditory and visual afferents. 62 cells were excited by forelimb group I afferents, two of them additionally from corresponding hind limb afferents. Forelimb group II afferents co‐excited about 70 % of the cells. All group I activated cells were excited by low threshold forelimb skin afferents. Low threshold joint afferents did not influence group I cells. Forelimb high threshold joint afferents activated about 40 % of the group I neurones. Three types of forelimb short latency excitation motivated a classification of the cells as; primary cortical group I cells, primary cortical mixed cells and primary cortical cutaneous cells. Some group I cells were excited by different hind limb afferents. Only 8 of the group I cells were discharged by auditory or visual afferents. 9 cells were inhibited or received mixed inhibition‐excitation from group I forelimb afferents. The latencies of the group I inhibitory potentials suggested that they were evoked by cortical interneurones. Forelimb group II‐ and skin afferents converged with inhibition on the group I inhibited neurones. Cells uninfluenced by group I afferents received excitation from other afferents or did not respond to the inputs used. The results are discussed in relation to previous studies on forelimb group I projections.
Potentiation of the Gastric Secretory Response to Sham Feeding in Dogs by Infusions of Gastrin and Pentagastrin1
Authors: Sjödin Lars 
Published: December 2008

AbstractThe gastric acid secretory response to sham feeding in dogs provided with esophagostomies and Pavlov pouches was related to the length of the sham feeding period. In antrectomized dogs the response even to prolonged sham feeding (30 min) was small. When a small supra‐threshold dose (0.30 μg/kg/h) of synthetic human gastrin I or pentagastrin was infused, these dogs responded markedly to a short period of sham feeding (1 min), When the sham feeding period was prolonged to 10 min subthreshold amounts of gastrin and pentagastrin (0.06 μg/kg/h or less) sufficed to enhance the sham feeding response. The enhancement fulfilled the criterion proposed by Gaddum for true potentiation. The pepsin output was also increased when the sham feeding period was prolonged. In the antrectomized dogs pepsin output after sham feeding was not significantly changed when the dose of gastrin infused was increased from 0.06 to 0.30 μg/kg/h or when the dose of pentagastrin was increased from 0.30 to 1.20 μg/kg/h.
Recurrent Depression from Motor Axon Collaterals of Supraspinal Inhibition in Motoneurones
Authors: Hultborn H. , Udo M. 
Published: December 2008

AbstractThe recurrent effects from motor axon collaterals have been examined on inhibitory transmission to motoneurones from the cortico‐, rubro‐ and vestibulospinal tracts and a pathway descending in the medial longitudinal fasciculus. Disynaptic vestibulospinal IPSPs in knee flexor motoneurones were always considerably decreased by conditioning antidromic volleys. No recurrent effects were found on disynaptic IPSPs evoked from the medial longitudinal fasciculus or from the red nucleus in knee extensor motoneurones. The transmission of polysynaptic cortical and rubral IPSPs was sometimes recurrently inhibited but more efficiently in flexor motoneurones than in extensor motoneurones. Susceptibility to recurrent depression is taken to indicate that the descending IPSPs are mediated by Ia inhibitory interneurones since impulses in motor axon collaterals, via Renshaw cells, give rise to a selective inhibition of these interneurones. Those IPSPs which are unaffected by ventral root stimuli are assumed to be transmitted through other interneurones.