bluuebunny/crossref_metadata_2025 huggingface dataset:
Reflex Changes in Sympathetic Activity and Arterial Blood Pressure Evoked by Afferent Stimulation of the Renal Nerve
Authors: Aars H. , Akre S.
Published: December 2008

The effects of afferent stimulation of renal nerves on efferent sympathetic activity and systemic blood pressure were studied in anesthetized rabbits. In most animals, afferent impulses pro duced reduction or abolition of sympathetic activity and a fall in blood pressure. High fre quencies of stimulation (20–30 pulses/sec or more) caused a more marked and long‐lasting depression of efferent activity and blood pressure than low frequencies. The highest sensitivity of blood pressure to variations in stimulation frequency was found in the range of 1–10 pulseslsec. Stimulation of the renal afferents had qualitatively the same effect on sympathetic activity and blood pressure as aortic nerve stimulation, but for the aortic nerve, higher stimu lation frequencies were required to obtain the same reduction in blood pressure. It is con cluded that afferent activity in renal nerves has a predominantly inhibitory effect on vasomotor activity, resulting in a fall in blood pressure.
Secretive Pressure Exerted by the Stimulated Nasal Salt Gland in Larus Argentatus (Herring Gull)
Authors: Håkansson C. H. , Malcus B.
Published: December 2008

Investigations of the dynamics of the nerve stimulated nasal salt gland of the Larus argentatu (Herring Gull) have shown that intraglandular duct anastomoses permit the gland to secret through one duct if the other is occluded. The force to extrude the secretion by maxima stimulation and uncatheterized ducts is lower than 40 mm H2O. The pressure force when botl ducts were occluded was measured to 430 mm H2O maximally.
Transmembrane Transport of Chloride and Iodide in Proximal Rat Tubules
Authors: Danielson B. G. , Person E. , Ulfendahl H. R.
Published: December 2008

The transport mechanism for chloride across the proximal tubular epithelia in the rat was investigated with a free‐flow micropuncture technique. The purpose of the investigation was to determine whether there is an active carrier system for chloride transport out of the tubule with different affinities for different halides and higher for iodide than for chloride. The TF/P values for sodium, potassium, chloride and iodide were determined simultaneously. The TF/P value for chloride (1.15) was significantly lower than the TF/P value for iodide (1.73). It was concluded that there is no evidence of an active transport system and that chloride and iodide are transported passively out of the tubular lumen, the permeability for iodide being somewhat lower than for chloride.
Pulmonary Gas Exchange as Influenced by G‐Induced Shifts in Central Blood Volume
Authors: MCosenhamer G. R.
Published: December 2008

Experimental observations are presented on interrelationships between G‐induced displacements of blood volume and pulmonary function. A statistically significant correlation is demonstrated between the changes in the “central blood volume” and venous admixture in the lungs. A possible explanation may be that a large G‐induced displacement of blood volume from intra‐ to extrapulmonary blood vessels results in a less marked pa+ distension of the dependent pulmonary blood vessels, and therefore in higher regional V/Q ratios, than if the G‐induced drain of blood out of the lungs is pronounced. This explanation is supported by previous observations that G‐induced venous admixture increases when peripheral pooling of blood is counteracted by the action of the leg muscle pump.
Relaxing and Metabolic Actions of ACTH in Rabbit Colan
Authors: Anderson Rolf , Mohme‐Lundholm Ella , Svedmyr Nils , Vamos Nandor
Published: December 2008

Andersson, R., E. Mohme‐Lundholm, N. Svedmyrand N. Vamos,Relaxing and metabolic actions of ACTH in rabbit colon. Acta physiol. scand. 1971.81. 11–17.

ACTH in the dose range of 0.15–4.60 IU/ml relaxed the circular muscular layer of rabbit colon contracted by carbacholine. The content of cyclic AMP was doubled. There was an activation of phosphorylaseawhich gave the same dose‐effect and time‐effect curves as thc relaxing action. The hexose phosphate and creatine phosphate contents of the muscle also increased. The relaxing and metabolic actions of ACTH were completely blocked by an adrenergic β‐receptor blocking agent (sotalol). The type of inhibition was competive. The relaxing action of ACTH was potentiated by theophylline and puromycin, agents which inhibit the enzymatic hydrolysis of cyclic AMP. The relaxing and metabolic actions of ACTH were similar to those of isoprenaline. They could be reproduced by cyclic AMP. In contrast to cyclic AMP and isoprenaline, ACTH did not decrease the adenosine triphosphate contcnt of thc muscle. It is suggested that the relaxing action of ACTH is mediated by thc adcnyl cyclase‐cyclic AMP system.
Canjoint Action of Sodium and Angiotensin on Brain Mechanisms Controlling Water and Salt Balances
Authors: Andersson B. , Eriksson L.
Published: December 2008

Andersson, B. and L. Eriksson, Conjoint action of sodium and angiotensin on brain mechanisms controlling water and salt balances. Acta physiol. scand. 1971. 81. 18–29.

The effects on water and salt balances of a simultaneous infusion of angiotensin and hypertonic NaCl into the 3rd brain ventricle were studied in goats in normal water balance and in hydrated animals. For comparison similar infusions of angiotensin alone (solved in slightly hypotonic saline) and of hypertonic NaCl were made. Like the hypertonic NaCl, 30 min infusions of angiotensin alone induced drinking in animals in normal water balance, and an inhibition of the water diuresis in the hydrated goat. The simultaneous infusion of both substances resulted in a marked potentiation of the dipsogenic and the antidiuretic effects. A possible explanation may be that angiotensin facilitates the transport of Na+ into brain cells regulating thirst and ADH release, and that the intracellular Na+ concentration rather than strictly osmotic factors determines the activity of these cells. In the hydrated goat a central effect of angiotensin strongly enhanced the natriuretic response to intraventricular infusions of hypertonic NaCl, and extreme natriuresis developed as result of the combined infusions in hydrated, salt‐supplemented animals. During normal water balance this sodium‐angiotensin synergism was less obvious, which suggests that both an expanded fluid volume and an elevated intracellular Na+ concentration are needed for optimal activation of a brain mechanism which stimulates renal Na' excretion, The time course of the centrally induced natriuresis indicates that the effect on the kidney may be mediated by a humoral agent.
Interindividual Differences in Diurnal Variations in Alertness, Performance, and Adrenaline Excretion
Authors: Pátkai Paula
Published: December 2008

Pátkai, P. Interindividual differences in diurnal variations in alertness, performance, and adrenaline excretion. Acta physiol. scand. 1971. 81. 35–46.

Subjects classified as habitual morning vs. evening workers on the basis of their answers to a questionnaire, were compared with regard to day‐time variations in catecholamine excretion and performance. Adrenaline excretion in morning workers was highest in the morning and decreased gradually during the day, while evening workers showed nearly constant excretion values. The performance of morning workers did not vary during the day, while evening workers showed a steady improvement, performing best in the evening. In addition, a significant difference between the two groups was found in the personality dimension of extraversion‐introversion, showing that evening workers were more extravert and morning workers more introvert. The constancy of individual diurnal rhythms and their relations to personality traits, are discussed.
Cerebellar Suppression of the Autonomic Components of the Defence Reaction
Authors: Lisander Bjorn , Martner Jan
Published: December 2008

Lisander, B. and J. Martner, Cerebellar suppression of the autonomic components of the defence reaction. Acta physiol. scand. 1971. 81. 84–95.

Experiments were performed on anesthetized‐curarized cats, where both the hypothalamic defence area and the cortex of the anterior cerebellar lobe could be stimulated while blood pressure, heart rate and muscle blood flow were recorded. Cerebellar stimulation which, when performed alone, had only insignificant cardiovascular effects, considerably reduced the increases in heart rate, blood pressure and muscle blood flow elicited by standardized defence area stimulations. The cerebellar suppression of the muscle vasodilatation appeared to be due to an interference with the cholinergic vasodilator fibre activation as elicited from the defence area. Thus, after complete pharmacological blockade of all adrenergic effects on the cardiovascular system, defence area stimulation still caused a marked, atropine‐sensitive muscle vasodilatation but this dilatation could be reduced by comcomitant cerebellar stimulation. In contrast, even strong activations of the baroreceptors did not interfere with the vasodilator fibre discharge as elicited from the defence area.

Therefore, while the inhibitory baroreceptor reflex and the defence reaction because of their differentiated interaction act in synergism from the hemodynamic point of view (see Kylstra and Lisander 1970) the cortex of the anterior cerebellar lobe tends to suppress the defence reaction by exerting an inhibitory influence on essentially all the autonomic components of this response pattern.
Heparin‐Induced Increase of Diamine Oxidase in Lymph and Blood Plasma of Rat, Guinea‐pig and Rabbit
Authors: Hansson Roy , Thysell Hans
Published: December 2008

After i.v. injection of heparin (1.6 IU/g b.w.) there was a significant increase of the diamine oxidase (DAO) activity in lymph and blood plasma in rat, guinea‐pig and rabbit. The ratio between lymph and plasma DAO activity was higher in rat and rabbit than in guinea‐pig under basal conditions. This difference was even more pronounced after heparin injection. Withdrawal of mesenteric or thoracic duct lymph from the circulation of the animals was accompanied by a poor response to heparin of the plasma DAO activity in rat and rabbit, whereas the response in the guinea‐pig seemed to be uninfluenced. These results suggest that, in analogy with earlier findings in man, the contribution from lymph to the heparin‐induced DAO response in blood plasma may be significant in the rat and rabbit, but not in the guinea‐pig.
Changes in the Electrochemical Potential Difference for HCO3‐‐ between Blood and Cerebrospinal Fluid and in Cerebrospinal Fluid Lactate Concentration during Isocarbic Hypoxia1
Authors: Mines A. H. , Sørensen S. C.
Published: December 2008

The changes in csf [HCO3‐] and [lactate] were followed in dogs whose arterial pH, Pco2, and [HCO3‐‐] were kept constant during 6 hrs hypoxia or normoxia. The results confirm that hypoxia causes a lowering of [HCO3‐]csf. We believe it is reasonable to assume that an increased anaerobic glycolysis in the brain is responsible for titrating HCO3‐‐ out of csf during isocarbic hypoxia although the lactate concentration in csf increased only about one third as much as the [HCO3‐‐] decreased. The action of hypoxia on [HCO3‐] esf is expressed in terms of its effect on the electrochemical potential difference for HCO3‐‐ between mean capillary plasma water and csf.
The Relative Contributions of Sodium and Chloride Ions to the Conductance of Toad Skin in Relation to Shedding of the Stratum Corneum
Authors: Larsen Erik Hviid
Published: December 2008

By means of short‐circuit and tracer technique, sodium transport, chloride transport, and D. C. conductance have been studied in toad skin in relation to moulting. It is shown that the skin loses its permselectivity, and that active sodium conductance increases as desquamation takes place. Subsequently the passive sodium permeability is lowered relative to the chloride permeability. The results are compatible with the hypothesis (Ussing and Windhager 1964), that the amphibian skin suppresses loss of ions along the extracellular pathway by means of tight junctions confined to the surface cells of the epithelium. It is confirmed that a rate limitation of the active sodium transport is located in the outermost part of the skin.
On the Innervation of the Slowly Adapting Stretch Receptor of the Crayfish‘ Abdomen. An Electrophysiological Approach
Authors: Jansen J. K. S. , Njå A. , Ormstad K. , Walloe L.
Published: December 2008

The synaptic effects of efferent fibres innervating the slowly adapting stretch receptor have been determined by intracellular records from reflexly intact receptors. Three such efferent fibres have been functionally identified. They all have an inhibitory action on the receptor and they probably correspond to the three efferent fibres described anatomically by Alexandrowicz (1967). The three types of IPSPs have similar reversal potentials and it is suggested that their synapses are intermingled and distributed over the somadendritic complex of the receptor. The inhibitory efficiency of the three types of IPSPs are markedly different, that of the thick accessory fibre being about five times more effective than the other two.
Metabolism of 14C‐Histamine in Domestic Animals
Authors: Eliassen K. A.
Published: December 2008

The metabolism of 14C‐histamine injected i.v. in 3 ruminant species (goat, sheep, and cow) has been studied previously. In the present study isotope dilution‐ and paper chromatographic techniques were used to examine urinary 14C‐metabolites of i.v. injected 14C‐histamine in the horse and the pig. The urine excreted the first 24 hrs after injection accounted for 64–76 % and 81–91 % of the radioactivity injected in horses and pigs, respectively. Less than 2 % of the injected radioactivity could be accounted for in the feces excreted the first week after injection. Known metabolites in the first 24 hr urine on an average accounted for about 94 % and 103 % of the urinary radioactivity in horses and pigs, respectively. Methylation of his‐tamine to 1.4‐methylhistamine and further oxidation to 1.4‐methylimidazoleacetic acid was quantitatively the most important pathway for histamine degradation, accounting on an average for about 63 % and 76 % of the radioactivity in horse and pig urine, respectively. The horse and the pig seemed to metabolize histamine in quite a similar way which again was quite different from that previously found in the ruminants in which oxidative deamination of histamine to imidazoleacetic acid was the only pathway of quantitative importance. As in ruminants histaminol seemed to be a metabolite of i.v. injected histamine accounting for about 2 % of the urinary radioactivity. The specific radioactivity of histamine was about tenfold larger than for 1.4‐methylmidazoleacetic acid, in horses and pigs.
Intravascular Concentrations of Calcium and Magnesium Ions and Edema Formation in Isolated Lungs
Authors: Nicolaysen Gunnar
Published: December 2008

The perfusate concentration of Ca++ has been assumed to be important for the permeability of the exchange vessels to proteins; low [Ca++] is said to result in edema development. The possible role of perfusate [Mg++] in this connection has previously not been considered. In the present work the correlation between the perfusate concentrations of Ca++ and Mg++ and edema development has been analyzed.

In a perfused rabbit lung preparation edema developed at physiological intravascular pressures when the perfusate (plasma) [Ca++] was reduced to about 7. 10‐5 mM and the [Mg++] to about 1. 10‐3 mM by EDTA additions. Edema development was not seen at intravascular concentrations of Ca++ and Mg++ of about 4. 10‐5 and 4. 10‐1 mM, respectively. Such concentrations were achieved by addition of EGTA to the perfusate. Thus either the [Mg++] or the [Ca++] plus [Me++] in the perfusate must be the important parameter for the edema development. The changes in the capillary permeability induced by EDTA‐additions were largely reversible by addition of Ca++. This effect of Ca++ had a latency period of less than one min.
The Effect of Sympathetic Nerve Stimulation on Pulmonary Blood Volume in Isolated Perfused Lungs
Authors: Aarseth P. , Nicolaysen G. , Waaler B. A.
Published: December 2008

Aarseth, P. G. Nicolaysen, and B. A. Waaler, The effect of sympathetic nerve stimulation on pulmonary blood volume in isolated perfused lungs. Acta physiol. scand. 1971. 81. 448–454.

Stimulations of the vago‐sympathetic nerve trunk at 5–10 imp/sec have been carried out in isolated dog lung preparations perfused at constant volume inflow. When the left atrial pressure was kept at 3–4 cm of water, the predominant response to these stimulations was a weight reduction of the preparation. This response is interpreted as being due to a reduction in pulmonary blood volume. Nerve stimulations caused only small weight reductions, or even weight augmentations, when the left atrial pressure was at or near zero. The blood volume reductions resulting from nerve stimulations appeared to be mediated via sympathetic nerve fibres and an α‐receptor mechanism.
Loci of Neurogenic and Metabolic Effects on Precapillary Vessels of Skeletal Muscle
Authors: Folkow Bjorn , Sonnenschein Ralph R. , Wright David L.
Published: December 2008

Folkow, B., R. R. Sonnenschein, and D. L. Wright, Loci of neurogenic and metabolic effects on precapillary vessels of skeletal muscle. Acta physiol. scand. 1971. 81. 459–471.

By cannulation of a branch of the proximally clamped sural artery of the anesthetized cat, distal arterial pressure (DAP) in the gastrocnemius muscle was recorded. Measurement of blood flow, femoral arterial pressure and DAP allowed calculation of total resistance (Rt) and its partition into a distal component (Rd) which included precapillary sphincters and the smaller arterioles, and a proximal component (RP) which included the larger arteries. With sympathetic vasoconstriction, the initial increase in Rt was accounted for mainly by constriction of the distal vessels which then tended to relax; progressive constriction of proximal vessels accounted for most of the elevated Rt during the steady state; subsequent reactive hyperemia mainly involved distal vessels. Rt was less affected by sympathetic stimulation during exercise than when the muscle was at rest; constriction of distal vessels was more markedly reduced than that of proximal vessels. Ascending dilatation was evident during exercise. Sympathetic cholinergic vasodilatation mainly involved vessels more proximal to those which were dilated early in exercise. The findings are compatible with the concept that capillary flow distribution, as a function of terminal arterioles and precapillary sphincters, is adjusted by local factors towards an optimum for the prevailing metabolic level of the tissue.
Electrophysiological and Morphological Development of Leg and Neck Muscles in the Rat
Authors: Boëthius Jörgen
Published: December 2008

Boëthius, J. Electrophysiological and morphological development of leg and neck muscles in the rat. Acta physiol. scand. 1971. 81. 492–507.

Membrane potentials were measured in the neck, sartorius and gastrocnemius muscles of postnatal rats. The potential rose from a constant value of 60–70 mV up to adult values of 80–90 mV. This increase, taking about 5 days, was earliest in the neck and latest in the gastrocnemius muscle. In the electromyograms of newborn rats the voltage of the motor unit potentials was higher and the duration shorter in the neck than in the gastrocnemius muscle. Mono‐phasic motor unit potentials were more common in the gastrocnemius than in the neck muscle. Later, the gastrocnemius potentials became comparable to those of the neck musculature. In the neck musculature, myotubes (3–27 %) were only found during the first day. In the sartorius and gastrocnemius muscles about 20 9% of the muscle cells were myotubes at birth. In each muscle the myotube‐myocyte transformation was completed on the day when the rise in membrane potential started. The correlation between the development of the membrane potential and the myotube‐myocyte transformation was also investigated in muecles denervated at birth and subsequently reinnervated. In such muscles the percentage of myotubes was 20–27 % at a time when the membrane potentials were of adult magnitude.
The Effect of Deep Halothane Hypotension upon Labile Phosphates and upon Extra‐ and Intracellular Lactate and Pyruvate Concentrations in the Rat Brain
Authors: Nilsson Lorentz , Siesjö Bo K.
Published: December 2008

Nilsson, L. and B. K. Siesjö, The effect of deep halothane hypotension upon labile phosphates and upon extra‐ and intracellular lactate and pyruvate concentrations in the rat brain. Acta physiol. scand. 1971. 81. 508–516.

A study was made of the energy metabolism of the rat brain during deliberate hypotension induced by 2 % halothane and partial airway obstruction. A reduction of the mean arterial blood pressure to 30 mm Hg led to moderate increases in the extra‐ and intracellular lactate and pyruvate concentrations and in the lactate/pyruvate ratios, and to moderate decreases in the phosphocreatine content. At the same blood pressure level, hyperventilation with reduction of the PaCO2 to about 20 mm Hg aggravated the metabolic changes, indicating a further reduction of the cerebral blood flow. Although hypercapnia with an increase in tile PaCO2 to about 85 mm Hg decreased the tissue lactate content markedly, the oxidative metabolism was not normalized.

It is concluded that although halothane hypotension with a reduction of the mean arterial blood pressure to about 30 mm Hg leads to changes in the energy metabolism of the brain, the changes are so moderate that a critical degree of hypoxia probably can be excluded. This conclusion may be even more valid if the mean blood pressure is not allowed to fall to such low values, and if marked hyperventilation is avoided at very low blood pressures.
Action Potential Generation in Denervated Rat Skeletal Muscle
Authors: Redfern Paul , Thesleff Stephen
Published: December 2008

Redfern, P. and S. Thesleff, Action potential generation in denervated rat skeletal muscle. I. Quantitative aspects. Acta physiol. scand. 1971. 81. 557–564.

Action potential generation was studied at various periods up to one week after denervation in individual muscle fibres of the extensor digitorum longus muscles of the adult rat. To allow a comparison of action potential generation at various stages of denervation, it was necessary to establish adequate conditions for spike generation. It was found that when fibres were locally polarized to a level of ‐90 to ‐100 mV, and the external calcium concentrations was increased to 4 mM, the peak rate of rise and the overshoot of the action potential were maximal. Between 30 and 40 hrs following section of the motor nerve, the mean maximal rate of rise of action potentials, recorded under the aforementioned conditions, was reduced by about one third, and remained at about this reduced level during the subsequent days. Two days after denervation the resting membrane potential was reduced from a mean of 82 mV in innervated muscle to a mean of 68 mV, and remained at about this level for the remaining 5 days studied. The electrical time constant and the input resistance of the muscle fibres gradually increased during the 7 days following denervation, the time constant by about 70 % and the input resistance by about 50 %. With anodal polarization in denervated muscle no significant correlation was found between the resting membrane potential and the maximal peak rate of rise of the spike. It was concluded that denervation produces a genuine reduction in the rate of rise of the action potential in muscle fibre.
The Effect of Cordycepin on Nuclear RNA Synthesis in Nerve and Glial Cells
Authors: Grahn B. , Lovtrup‐Rein H.
Published: December 2008

The effect of cordycepin on RNA synthesis in isolated nuclei of neurones, astrocytes, and oligodendro‐ and microglial cells, is reported. This drug selectively inhibits the formation of ribosomal RNA and its precursors. Two independent components, with sedimentation coefficients of 25S and 12S, and high rate of turnover, remain however unaffected. They are shown to be non‐ribosomal RNAs and are assumed to be of messenger type. The effect of cordycepin is the same on all three types of nuclei studied.
Release of Histamine and Formation of Slow Reacting Substance in the Cat Paw Induced by Compound 48/80
Authors: Strandberg Kjell
Published: December 2008

A method for perfusion of cat paws with constant flow and temperature is described. This technique has been used to study the relationship between the efflux of histamine and slow reacting substance (SRS) from cat paws perfused with compound 48/80. The threshold dose of compound 48/80 was 0.001–0.01 μg/ml for both histamine and SRS releasing effects. No correlation between the yields of histamine and SRS was noted. On repeated administration of compound 48/80 the histamine releasing effect declined and the output of SRS was cor respondingly reduced. The release of histamine and the formation of SRS were inhibited by ninhydrin, N‐ethylmaleimide and potassium cyanide indicating that both processes are dependent on energy‐requiring enzymatic reactions. Apart from their antagonism of the histamine releasing effect of compound 48/80, ninhydrin and N‐ethylmaleimide released histamine per se. No SRS was detected in the effluents from paws perfused with these agents alone. The yields of both histamine and SRS were higher at 22o C than at 37oC. Regardless of temperature the efflux of histamine consistently preceded that of SRS. A temperature dependent inactivation of SRS by cat serum was demonstrated. The results suggest that the initial reaction(s) activated by compound 48/80 is common for the release of histamine and the formation of SRS in the cat paw but that these processes then proceed independently.
The Effect of Breathing on the Cardiovascular Adjustments Induced by Face Immersion in Man
Authors: Blix Arnoldus Schytte , Krog John , Myhre Hans Olav
Published: December 2008

Andersen (1963) has reported that bilateral interruption of the trigeminal nerve abolishes submersion bradycardia typical of ducks. A slowing of the heart upon face immersion of man has later been reported by several authors. (Craig 1963, Elsner et al. 1963, Brick 1966, Paulev 1969 and Song et al. 1969). Arrest of breathing, how ever, is obviously a consequence of face immersion of normal subject?. It would therefore be of interest to repeat these experiments in a person, who has the ability to continue to breathe normally while his head is kept under water i.e. a tracheosto‐mized man. Studies of the heart rate related to face immersion in this person may furnish valuable information concerning the afferent pathways involved in the establishment of the cardio‐vascular adjustments to diving in man.
Rapid Interaction between Gonadotrophic Hormones and the Prepubertal Rat Ovary
Authors: Ahrén Kurt , Hamberger Lars , Perklev Torsten
Published: December 2008

Lactic acid production by isolated ovaries from prepubertal rats was used as an experimental system to characterize the initial interaction between luteinizing hormone (LH) and human chorionic gonadotrophin (HCG) on the one hand and the ovarian tissue on the other hand. Injection of bovine LH, 30, 5 and 1 min, respectively, before extirpation of the ovaries from the rats, produced a marked increase in lactic acid production by the isolated ovaries during a following 2 hr incubation period. The effect was very pronounced already in ovaries from rats injected with LH for only 1 min before removal of the ovaries, but the effect was slightly more pronounced in the “5 rnin group”. There was, however, no significant difference between the “5 min group” and the “30 min group”. There were also persistent effects of both LH and HCG after 1–5 rnin exposure of the ovaries to the hormone in vitro followed by careful wash in hormone‐free medium. These effects did not become more pronounced when the hormone was also present during the entire 2 hr incubation period when lactic acid production was measured. The same rapid interaction between hormone and ovary was seen at both +37° C and +l ° C. Addition of an anti‐HCG serum before or together with HCG completely prevented the effect of the hormone. When the ovaries were first exposed to HCG for 1 min and then to anti‐HCG serum for 1–5 min, the anti‐serum did not abolish the hormone effect. There was no cross‐reaction between anti‐HCG serum and bovine LH. The results are discussed in relation to similar experiments with other polypeptide hormones, and in relation to various theories of the initial interaction between the hormone and the target cell.
Thrombocytes and Pulmonary Vascular Resistance during Hemorrhagic Hypotension
Authors: Bø G. , Hognestad J.
Published: December 2008

Prolonged hemorrhagic hypotension can induce an increase in pulmonary vascular resistance (PVR). In anesthetized cats with open chests and with positive pressure ventilation aortic blood flow, pulmonary arterial‐, left atrial‐ and femoral arterial pressures were recorded. Eight animals were bled until the mean arterial pressure was 50 nun Hg and this level was main tained for 3 hrs by further bleeding and/or small retransfusions. The animals were then retransfused. Another group of 5 animals were made thrombocytopenic by shunting their blood through a column of glassbeads. These animals were then bled in the same way and kept hypotensive for the same period of time.

During hypotension PVR in the first group increased gradually and by 370 per cent (mean value). In the thrombocytopenic group PVR increased only by 125 per cent (mean value) (P<0.01). The number of thrombocytes in arterial blood in the former group of animals decreased gradually by 37 per cent during the hypotensive period. Only in 2 of the 8 animals in this group did examination with light microscopy reveal scattered thrombocyte aggregates in small pulmonary vessels.

The thrombocytes thus seem to be involved in the development of increased PVR during hemorrhagic hypotension. The fact that intravascular thrombocyte aggregates were not general ly found may indicate that the thrombocytes act by other mechanisms than by simple vascular obstruction alone.
Biological Evaluation of Protein Quality and Safety of a Lipoprotein Concentrate from Niger Seed* (Guizotia Abyssinica Cass.)
Authors: Eklund Anders
Published: December 2008

Growing rats were fed diets containing a lipoprotein concentrate prepared from niger seeds, as the sole source of protein. Protein efficiency ratio (PER) and productive protein value (PPV) were calculated for two levels of protein in the diet, 11.1 % and 22.4 %, respectively. When the protein content of the diet was 11.1 % the PER was 2.37 (for a feeding period of three weeks). The corresponding PPV was 42.0. A short term toxicological feeding study was carried out on rats fed with these diets for a 90‐day period. No significant diet‐related changes were observed in the growth, appearance, behaviour and survivals of the animals. Hematological findings were normal. The histopathological examinations of the main organs gave normal results. Electron microscopy showed an increased amount of multi‐vesicular bodies (possibly lysosomes) as well as an increased content of fat droplets in the cytoplasm of liver cells. The significance of these changes remains unclear.
The Influence of the Nigro‐Neostriatal Dopamine Pathway on Spinal Motoneuron Activity
Authors: Andén Nils‐erik , Larsson Knut , Steg Göran
Published: December 2008

Reserpine treatment of rats with a unilateral lesion of the nigro‐neostriatal dopamine neurons produced on the unoperated side a rigidity which could be demonstrated electromyographically in the calf muscles. There was also a more marked increase in the a‐ and a decrease in the γ‐motoneuron excitability on the side contralateral than ipsilateral to the lesion indicating that the nigro‐neostriatal dopamine neurons influence muscle tone by causing a shift of the balance between the α‐ and γ‐motoneuron activity.
The Effect of Protriptyline on Uptake and Retention of dl‐3H‐Nor adrenaline in Different Tissues of the Rat
Authors: Almgren Olle , Jonason Jan
Published: December 2008

The inhibition of3H‐noradrenaline (3H‐NA) uptake in submaxillary glands, spleens and heartr of the rat was studied after pretreatment of the animals with different doses of protriptyline (PTP). One μg/kg3H‐NA was administered intravenously 15 min after the intraperitoneal injection of PTP. The duration of the uptake blockade induced by 10 mg/kg PTP was also studied. To circumvent problems due to the blood flow, anin vitrotechnique was also used to compare the uptake and retention of3H‐NA in submaxillary glands and hearts. It was found that the3H‐NA uptake of the heartin vivonormally exceeds several times that of the submrtvillary glands, whilein vitrothe uptake was directly correlated to the concentration of endogenous NA. The data support the view that the greater blood flow through the heart is responsible for the major part of the difference foundin vivo. After PTP pretreatment the uptake inhibition was much stronger in the heart than in the other organs investigatedin vivo. Alsoin vitrothere was a more efficient inhibition of the3H‐NA uptake in the heart than in the submaxillary gland, both when 10 mg/kg PTP was given i.p. lo the animals 30 min prior to death and when 1μg/ml of the drug was present in the incubation medium. The factors deter mining the overall sensitivity of different organs to PTP are discussed.
Fibrinogen Degradation Products in Experimental Intravascular Coagulation Gel filtration and immunological studies
Authors: Zetterqvist Eric
Published: December 2008

Dogs injected with 125I‐fibrinogen were given: 1. a thrombin infusion during 1 hr, and 2. simultaneous infusions of epsilon aminocaproic acid (EACA) and thrombin, respectively. Platelet number, fibrinogen concentration and radioactivity in plasma, fibrinogen and serum were determined. Special comparative studies were made between one dog given thrombin and one given EACA together with thrombin. Samples obtained before and at 2 hrs after the start of the thrombin infusions were analyzed with respect to the radioactivity distribution in the blood and in plasma after Sepharose and Sephadex flitrations. Trials were made to identify the fibrinopeptides. The immunological behaviour of serum and of eluate fractions was studied. An occurrence of fibrinolysis in the dogs already before the thrombin infusions was indicated. After the thrombin infusions there was in plasma a wide variety of fibrinogen degradation products with the antigenic determinants of fibrinogen. No products with higher molecular weight than that of fibrinogen were demonstrable. When EACA was given together with thrombin there was an inhibition of degradation products. The results give further support for a secondary fibrinolysis in intravascular coagulation. No evidence was obtained for the occurrence of fibrinopeptides.
Effects of Parasympathomimetic Agents and Vagal Stimulation on the Flow in the Pancreatic Duct of the Cat
Authors: Lenninger Sven
Published: December 2008

Intravenous injection of methacholine and vagal stimulation increased the amount of juice secreted by the secretin‐stimulated pancreas of the cat. The increase was greater at low rates of secretion than at high. Methacholine and vagal stimulation as well as secretin retarded the flow of a salt solution, perfused through the gland. It is concluded that the cholinergic stimulation causes the gland to secrete but also increases the resistance to the flow in the duct, probably by luminal narrowing and by changes of the fluidity of the juice.
Pulmonary Transcapillary Exchange of 24Na and 51CrEDTA. An Evaluation of Factors Influencing the Extraction of these Tracers during one Passage through an Isolated Lung Preparation
Authors: Nicolaysen Gunnar
Published: December 2008

Experiments with the single injection indicator diffusion method have been carried out in an isolated, ventilated and plasma‐perfused rabbit lung preparation. A mixture of two diffusible tracers (24Na, 51CrEDTA) and one intravascular reference tracer (125I‐albumin) were used. Relative concentrations in the first indicator‐containing venous outflow fractions collected indicated that there had been some initial extraction of the diffusible indicators. A small extra‐vascular space of distribution appeared to represent the most important determinator for the extent of this initial extraction during one single passage through the vascular bed. Results from several types of experiments were consistent with there being also some moderate degree of diffusion limitation for the extraction of the diffusible tracers. Extraction of the diffusible tracers appeared to be moderately increased when the intravascular concentrations of both Ca++ and Mg++ were reduced to such low levels that edema was developing in the preparation. It appears unlikely though that the single injection indicator diffusion method in its present form can yield more detailed information on capillary permeability to small solutes in this rabbit lung preparation.
Spatial Specificity of Local Habituation to Cold
Authors: Eide R.
Published: December 2008

A series of daily cold exposures of 9 cm of the tail of 6 rats for 50 min for 17 days resulted in a significant reduction in the cardio‐acceleration to the cooling. This is conceived as habituation. When an additional 3 cm of the tail was immersed on the 18th day, the cardiac reaction increased markedly, showing that the habituation was specific to the part repeatedly exposed. A control experiment showed that this return of reaction was not a result of spatial stimulus summation. A smaller group of rats were exposed for 40 days with similar results. In a second series of experiments the ventral half of 3 cm of the tail of 8 rats were exposed to cold one hour a day for 17 days. A reduced cardio‐acceleration was found. Stimulation of the dorsal part of the same segmental area resulted in renewed cardio‐acceleration. This seems to indicate some degree of somatotopic organization of the habituation process.
A Fifth Modality of Taste
Authors: Andersen H. T. , Hartmann Å. O.
Published: December 2008

An analytical search for independent modalities of taste is presented. The correlation matrix between independent stimuli was calculated using data recorded from chorda tympani single fibres in rats (Erickson, Doetsch and Marchall 1965) assuming that specific taste sensations may be explained by an “across fibre pattern” input into gustatory primary afferents. The four main factors were first rotated since this number of factors would correspond to the common idea of four independent taste primaries; bitter, salty, sour and sweet. The corresponding re solution of stimuli on four factors was inadequate. However, by adding one more factor a striking separation on five factors was obtained. The salts used separated distinctly on two of the factors; the lithium and sodium salts on one, and the salts of the larger captions on the other. Sucrose, HCI and quinine‐hydrochloride correlate heavily with one and only one of the three remaining factors. These five main factors account for 92.6 % of the variance in the material. The conclusion may be drawn that an across‐fibre pattern contains taste modulicon sistent with the established concept of taste primaries, the primary referred to as salty, however, seems to consist of two independent moduli.
On the Relation between the Chorda Tympani Nerve Response, Arterial Oxygen Tension and Blood Flow in the Tongue of the Rat
Authors: Hellekant Göran
Published: December 2008

The summated chorda tympani respotise of the rat to taste stimtilation was recorded while, (a) the rat was artificially ventilated with hypoxic mixtures of oxygen‐nitrogen, (b) the blood flow through the ipsilateral coninion carotid artery and the intra arterinal tension were measured and (c) the tongue was pelfusrd with blood from one femoral artery The technique applied in (a) indicated that the animal was able to maintain its taste sensitivity until circulation collapsed. the methods of (b) showed tliat a decrease of taste response could be recorded even if the blood oxygen tension rose when the blood flow to the tongue dimmished. The results of (c) demonstrated that the taste response could be increasrd, maintained and decreased by changes of the blood flow to the tongue.
Antagonism of Slow Reacting Substance by Polyphloretin Phosphate on Isolated Human Bronchi
Authors: Mathé A. A. , Strandberg K.
Published: December 2008

Purified slow reacting substance (SRS) induced a marked and long lasting constriction of isolated human bronchi. No signs of tachyphylaxis in the response to SRS were observed. Blockade of adrenergic, cholinergic, histaminergic and 5–hydroxytryptaminergir receptors did not effect the bronchoconstricting action of SRS. Adrenaline, theophylline and dibutyryl cyclic AMP counteracted the bronchoconstriction induced by SRS. Polyphloretin phosphate (PPP) antagonized the action of SRS, both on isolated human bronchi and on isolated guinea‐pig ileum. Antagonism by PPP could be surmounted by higher doses of agonist, and there was a parallel shift of the dose response curves of the agonist indicating a cormpetitive antagonism. PPP did not modify the bronchoconstriction induced by acetylcholine and histamine.
Postnatal Excitability Changes of the Ankle Monosynaptic Reflexes in the Cat
Authors: Mellström Anders
Published: December 2008

The effects of repetitive stimulation on the amplitude of ankle extensor and flexor mono synaptic reflexes were studied under various experimental conditions in high spinal cats during postnatal development. The extensor monosynaptic reflex elicited from a dorsal root at 1/9 sec decreases initially when the stimulus rate is increased to 2/sec. This depression increases with age and is more pronounced in the flexor monosynaptic pathway than in the extensor one in the newborn kitten. This latter observation and the demonstration of a subliminal fringe in the flexor motoneurone pool of the newborn kitten indicate an earlier maturation of the flexor monosynaptic pathway. In young kittens the extensor monosynaptic reflex decreases less with increasing rate of stimulation when elicited from a dorsal root than from a peripheral nerve. In older kittens the reverse is true. Prolonged stimulation reduces the differences between dorsal root and peripheral nerve stimulation. In young kittens prolonged dorsal root stimulation at 2/sec causes a decrease of the extensor monosynaptic response. In adult animals on the other hand it increases. The flexors show a passing increase and subsequent decrease in young kittens during prolonged stimulation and in the adult there is only a decrease. Nembuta® depresses the extensor monosynaptic potential and accentuates frequency‐dependent depression variably with age.
Recurrent and Antidromic Effects on the Monosynaptic Reflex during Postnatal Development in the Cat
Authors: Mellström Anders
Published: December 2008

The recurrent effects on the amplitude of the ankle extensor and flexor monosynaptic reflexes were studied at different rates of stimulation during postnatal development in high spinal cats. The recurrent + antidromic effects on the ankle extensor monosynaptic reflex were also in vestigated. Recurrent inhibition of extensors was observed in the youngest kittens but disappeared more or less during the first postnatal month to reappear during the first part of the Second month. At that time, recurrent inhibition of flexors also appeared as did recurrent facilitation. All recurrent effects were found to increase with stimulation frequency and, with the exception of the extensors during the first month, they also increased in both magnitude and duration with age, reaching adult values during the second postnatal month. It was concluded that the increased recurrent effects are partly due to a reduction of the excitability in the monosynaptic pathway, although a postnatal change in the recurrent effects per se can not be excluded. Recurrent + antidromic effects on the extensors were also found to increase in magnitude and duration with increasing age.
Electrolyte Distribution and Renal Function in the Hibernating Hedgehog
Authors: Clausen Gunnar , Storesund Asbjörn
Published: December 2008

The concentrations of Na, K, Mg and CI were determined in muscles and liver, various zones of the kidney, plasma, red blood cells, and bladder urine in active and hibernating hedgehogs. Freezing point depression and urea concentration were determined in the kidney, plasma and urine. Unaltered tissue water concentration and 15 to 20 per cent decreased CI and Na space suggest a shift of water from the interstitium to the cells during hibernation. Hibernation tended to alter the partition of electrolytes, between tissues and plasma, similarly to in vitro cooling of mammalian tissues. The bladder urine to plasma ratios of solute concentrations during hibernation, were: Na = 0.18, CI = 0.11, K = 6.4, Mg = 3.7, urea = 28, osmolarity = 3.4. Thus the extracellular ions Na and CI are conserved relative to the intracellular ions during the hibernating season. The osmolarity and the concentrations of urea, Na and CI did not increase from cortex to papilla in the kidneys of hibernating hedgehogs. Since the renal counter current mulitiplier system therefore is practically inoperative, the hyperosmotic bladder urine (1.1 Osm/l) sampled during hibernation must be produced during the intermittent arousal periods and not during hibernation.
Specificity of Sensory Messages Mediated through Chorda Tympani Fibres with Multiple Sensitivity to Gustatory and Thermal Stimuli
Authors: Andersen H. T. , Hartmann Å. O.
Published: December 2008

Sensory messages about taste and temperature transmitted through single chorda tympani fibres have been studied by means of factor analysis using the varimax criterion for factor rotation. Our analysis indicate that all sensory qualities studied, i.e. varm, cold, salty, sour, sweet and bitter are conveyed to the brain as separate sensory modalities. No groups of interacting stimuli could be identified at the level of the primary afferent neuron. It seems particularly important that the pattern of neural activity elicited by gustatory qualities may change over time so that the dynamic properties of the transmission system emerges as a possible mechanism of sensory discrimination. Moreover, this time dependent shift in the input of information to the central nervous system may give a clue to the phenomenon of aftertaste.
The Effect of Glucagon on Intestinal Motility and Blood Flow
Authors: Fasth S. , Hultén L.
Published: December 2008

The mechanism by which glucagon inhibits intestinal and vascular smooth muscle tone was studied in anesthetized cats. The intestinal motility was recorded by a volume recording device and the intestinal blood flow by connecting the left carotid artery via a drop recording unit with the superior mesenteric artery by a wide bore polyethylene tube. A femoral artery was used for recording of arterial pressure. Glucagon was administrated close intraarterially at different rates. In animals where the adrenals were left intact glucagoninfusion was followed by a considerable and immediate increase of intestinal blood flow and a somewhat delayed motility inhibition and blood pressure increase. When the adrenals were excluded glucagon still induced a blood flow increase. The motility inhibition and the blood pressure increase were both abolished, however. It is therefore suggested that glucagon exerts its action on the splanchnic area in two different ways, on the one hand by a direct effect on the vascular smooth muscles on the other hand by a release of catecholamines from the adrenal medullae which, in turn, inhibits intestinal smooth muscles.