bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional development of the visual system in normal and protein deprived rats. Ill: Recordings from adult optic nerve in vitro
Authors: SJÖSTRÖM A. , CONRADI N. G. , GUSTAFSSON B. , WIGSTRÖM H. 
Published: December 2008

SJÖSTRÖM, A., CONRADI, N.G., GUSTAFSSON, B. & WIGSTROM, H. 1985. Functional development of the visual system in normal and protein deprived rats. III: Recordings from adult optic nerve in vitro. Acta Physiol Scand, 125, 353–358. Received 8 March 1985, accepted 20 April 1985. ISSN 0001–6772. Departments of Physiology and Pathology, University of Goteborg, Sweden.A persistent increase in the latencies of the visual evoked response recorded from the cortical surface of protein deprived adult rats was described recently (SJÖSTRÖM et al. 1984). The morphological correlate to this alteration is unknown. Previous studies on malnourished rats have shown a reduction of axonal diameters and in the number of myelin lamellae in relation to axonal circumference, and hence the possibility of a decrease in fibre conduction velocity must be considered. In parallel study, we have established that changes in diameters and myelination of optic nerve fibres similar to those previously reported in malnourished rats are present in adult protein deprived (PD) rats (Conradi el al. 1985). In the present paper, recordings of optic nerves in vitro from adult normal (C) and protein deprived (PD) rats are described. The compound action potentials were very similar in the two groups. Three positive peaks were easily defined probably corresponding to three functional groups of optic nerve fibers. No significant differences in amplitudes or conduction velocities for the three peaks were found between the C and PD rats. It is concluded that the increased latencies of the evoked response are not caused by a decrease in conduction velocity.
Effects of halothane on the transducer and potential activated currents of the crustacean stretch receptor
Authors: SWERUP C. , RYDQVIST B. 
Published: December 2008

SWERUP, C. & RYDQVIST, B. 1985. Effects of halothane on the transducer and potential activated currents of the crustacean stretch receptor.Acta Physiol Scand125, 359–368. Received 20 February 1985, accepted 20 April 1985. ISSN 0001–6772. Department of Physiology II, Karolinska Institute, Stockholm, Sweden.Halothane was applied to the stretch receptor neuron of the crayfish (Astacus astacus) and the effects on the transducer properties and the potential activated currents were studied with potential clamp technique using two microelectrodes. Exposure to halothane reduced the frequency of action potentials during stretch. This was shown to be due to effects both on the action potential generating currents and the transducer current. Halothane partially blocked the TTX sensitive fast inward current in a dose‐dependent manner (Apparent KD= 3 mM). Halothane also reduced the outward current produced by a positive potential step. Both the fast and the slow component were affected, although the fast outward current seemed to be most sensitive. There was little or no change in the currents resulting from negative potential steps. The peak of the receptor potential and the receptor current were very little affected by halothane. The amplitude of the static phase of the receptor potential was reduced to a greater degree than the static phase of the receptor current (cells treated with TTX). A change in reversal potential of about –13 mV was observed for the peak and the static phase of the receptor current in four cells indicating an increased cord conductance for the transducer channel.
Dual effects of adenosine and adenosine analogues on motor activity of the human fallopian tube
Authors: SAMUELSON ULF E. , WIKLUND N. PETER , GUSTAFSSON LARS E. 
Published: December 2008

SAMUELSON, U.E, WIKLUND, N.P. & GUSTAFSSON, L.E. 1985. Dual effects of adenosine and adenosine analogues on motor activity of the human fallopian tube. Acta Physiol Scand125, 369–376. Received 24 January 1985, accepted 20 April 1985. ISSN 0001–6772. Department of Physiology, Karolinska Institute, and National Institute of Environmental Medicine, Stockholm, Sweden.Effects of adenosine and adenosine analogues on spontaneous contractility of the human fallopian tube during different phases of the menstrual cycle were studied. In isthmic preparations, a stimulatory effect by L‐N6‐phenylisopropyladenosine (L‐PIA), with preference for adenosine A1‐receptors, was seen mainly during the proliferative phase. In ampullary preparations, stimulation by L‐PIA was seen both in the secretory and proliferative phases. Adenosine and 2‐chloroadenosine exerted similar stimulatory effects. 5′‐N‐ethylcarboxamide‐adenosine (NECA), with selectivity for adenosine A2‐receptors, or D‐PIA never showed a stimulatory effect. At concentrations above those needed for stimulation, adenosine, 2‐chloroadenosine and L‐PIA inhibited spontaneous contractions, in common with NECA and D‐PIA. Here, NECA was more potent than L‐PIA. The D‐PIA and L‐PIA were equipotent. The inhibition was seen during the whole menstrual cycle. The competitive adenosine antagonist 8‐j>‐sulphophenyltheophylline (PSOT) reversibly antagonized the stimulatory and inhibitory effects elicited by adenosine and the analogues. The PSøT alone could exert a stimulatory or an inhibitory action on spontaneous contractility. We suggest that adenosine can modulate contractile activity in the human fallopian tube via stimulatory A1 ‐ and inhibitory A2 ‐ receptors. These receptors are located on the smooth muscle cells, and might act via cAMP. The relative receptor dominance may be influenced by cyclic hormonal changes.
Mechanism of hypergastrinaemia after nephrectomy in the rat
Authors: EKELUND M. , MUNSHID H. A. EL , HÅKANSON R. , REHFELD J. F. 
Published: December 2008

EKELUND, M., EL MUNSHID, H.A., HÅKANSON, R. & REHFELD, J.F. 1985. Mechanism of hypergastrinaemia after nephrectomy in the rat. Acta Physiol Scand 125, 383–388. Received 17 September 1984, accepted 1 May 1985. ISSN 0001–6772. Departments of Pharmacology and Surgery, University of Lund, Lund, Sweden, and Department of Clinical Chemistry, Rigshospitalet, Copenhagen, Denmark.Bilateral nephrectomy in the rat is followed by hypergastrinaemia and by activation of gastric histidine decarboxylase. The enzyme activity is thought to reflect the concentration of circulating gastrin. While there is general agreement that post‐nephrectomy hypergastrinaemia is primarily the result of loss of renal elimination of gastrin, it remained to be determined whether gastrin secretion could be stimulated in the hypergastrinaemic state and whether it contributed to the hypergastrinaemia. Histamine, but not pentagastrin, is known to evoke gastric acid secretion in the nephrectomized rat, and histamine, but not pentagastrin, was found to lower the serum gastrin level and the gastric histidine decarboxylase activity, indicating that after nephrectomy gastrin was still secreted and that the secretion could be suppressed by increased acid output. The importance of gastrin secretion for post‐nephrectomy hypergastrinaemia was assessed further by investigating the effect of nephrectomy on the serum gastrin concentration in rats previously subjected to operations that had either reduced (e.g. antrectomy) or raised (e.g. antrum exclusion) the serum gastrin concentration. Post‐nephrectomy serum gastrin levels co‐varied with the levels before nephrectomy. Thus, the capacity to secrete gastrin was not abolished by nephrectomy. Finally, nephrectomy greatly affected the linear correlation between the serum gastrin concentration and the gastric histidine decarboxylase activity in a manner suggesting the operation of a gastrin‐independent factor capable of activating the enzyme.
Acute continuous exposure to cigarette smoke produces discrete changes in cholecystokinin and substance P levels in the hypothalamus and preoptic area of the male rat
Authors: FUXE KJELL , SIEGEL RICHARD A. , ANDERSSON KURT , ENEROTH PETER , MASCAGNI FRANCO , AGNATI LUIGI F. 
Published: December 2008

FUXE, K., SIEGEL, R.A., ANDERSON, K., ENEROTH, P., MASCAGNI, F. & AGNATI, L.F. 1985. Acute continuous exposure to cigarette smoke produces discrete changes in cholecystokinin and substance P levels in the hypothalamus and preoptic area of the male rat. Acta Physiol Scand 125, 437–443. Received 8 January 1985, accepted 7 May 1985, TSSN 0001–6772. Department of Histology, Karolinska Institute, Stockholm, Sweden, Research and Development Laboratory, Department of Obstetrics and Gynaecology, Karolinska Hospital, Stockholm, Sweden, Deutsches Primaten Zentrum, Gottingen, FRG, and Department of Human Physiology, University of Modena, Italy.By means of a Walton Horizontal Smoking Machine, male rats were exposed to the smoke from 1–4 cigarettes burned in a continuous fashion. Cholecystokinin (CCK) and substance P levels (determined by means of radio‐immunoassay) were measured in discrete hypothalamic and preoptic regions. Acute continuous exposure to cigarette smoke induced increases in CCK levels in the paraventricular hypothalamic region as well as decreases in CCK levels in the median eminence. Furthermore, this treatment resulted in decreased CCK and substance P levels in the medial preoptic region. The results have been interpreted to indicate that CCK and substance P containing neuronal systems can be regulated by cholinergic nicotine‐like receptors.
Determinants of pulmonary blood volume. Effects of acute changes in airway pressure
Authors: THORVALDSON JØRGEN , ILEBEKK ARNFINN , KIIL FREDRIK 
Published: December 2008

THORVALDSON, J., ILEBEKK, A. & KIIL, F. 1985. Determinants of pulmonary blood volume. Effects of acute changes in airway pressure. Acta Physiol Scand 1985, 125, 471–479. Received 2 November 1984, accepted 10 May 1985. ISSN 0001–6772. Institute for Experimental Medical Research, University of Oslo, Ullevaal Hospital, Norway.To examine the effects of airway pressure (AWP) on pulmonary blood volume (PBV) at various pulmonary vascular pressures and flows, experiments were performed in anaesthetized, open‐chest dogs. The AWP was raised by elevating end‐expiratory pressure, and PBV was calculated as the product of electromagnetic aortic flow and pulmonary mean transit time for ascorbate (polarographic method). When AWP was raised from 3 to 13 mmHg, changing lung conditions from zone 3 [left atrial pressure (LAP) higher than AWP] to zone 2 (AWP higher than LAP), PBV decreased by 14.5 7plusmn; 6.2%. When LAP was raised above 7 mmHg at constant pulmonary arterial pressure (PAP), PBV increased under zone 2 but not under zone 3 conditions. During blood volume expansion to LAP 15 mmHg, PBV rose by 30–50% and became equal at AWP of 4 and 14 mmHg, whereas the pulmonary vascular resistance remained 40% higher at high AWP. These data suggest that PAP, LAP and AWP regulate PBV by acting on compliant vessels surrounding the alveoli. Under zone 2 conditions with collapsed aveolar capillaries, elevation of LAP results in re‐expansion of the alveolar capillaries, and PBV is restored without a rise in PAP. Under zone 3 conditions, a rise in LAP cannot increase PBV without raising PAP, explaining why PBV remains constant when PAP is kept constant.
Rotational behaviour elicited by intracerebral injections of apomorphine and pergolide in 6‐hydroxy‐dopamine‐lesioned rats. I: Comparison between systemic and intrastriatal injections
Authors: HERRERA‐MARSCHITZ MARIO , FORSTER CHRISTINE , UNGERSTEDT URBAN 
Published: December 2008

HERRERA‐MARSCHITZ, M., FORSTER, C. AND UNGERSTEDT, U. 1985. Rotational behaviour elicited by intracerebral injections of apomorphine and pergolide in 6‐hydroxy‐dopamine‐lesioned rats. I. Comparison between systemic and intrastriatal injections.Acta Physiol Scand1985, 125, 519–527. Received 12 March 1985, accepted 22 May 1985. 0001–6772. Department of Pharmacology, Karolinska institutet, S‐104 01 Stockholm, Sweden.Rotational behaviour in unilaterally 6‐hydroxy‐dopamine‐denervated rats has been attributed to stimulation of dopamine receptors on striatal as well as limbic areas. In the present study the rotational behaviour elicited by local intrastriatal injections of apomorphine or pergolide was compared to the rotation elicited by systemic injections of the drugs. We found that intrastriatal injections induced rotational behaviour almost identical to the behaviour occurring after systemic treatment. Furthermore, studies of the spread of [3H]apomorphine in brain tissue showed that at the peak of rotation the radioactivity was confined within the limits of the striatum. Non‐significant amounts of radioactivity was found in the nucleus accumbens. On the basis of these data we conclude that rotational behaviour elicited by systemic injections of apomorphine or pergolide originates from stimulation of striatal sites. The difference in rotational patterns elicited by these drugs is more likely to relate to differences in receptor stimulation within the striatum than differences in, for example, relative distribution between limbic and striatal areas.
Rotational behaviour elicited by intracerebral injections of apomorphine and pergolide in 6‐hydroxy‐dopamine‐lesioned rats. II: The striatum of the rat is heterogeneously organized for rotational behaviour
Authors: HERRERA‐MARSCHITZ MARIO , FORSTER CHRISTINE , UNGERSTEDT URBAN 
Published: December 2008

HERRERA‐MARSCHITZ, M., FORSTER, C. & UNGERSTEDT, U. 1985. Rotational behaviour elicited by intracerebral injections of apomorphine and pergolide in 6‐hydroxy‐dopamine‐lesioned rats. II: The striatum of the rat is hetergeneously organized for rotational behaviour.Acta Physiol Scand125, 529–535. Received 12 March 1985, accepted 22 May 1985. ISSN 0001–6772. Department of Pharmacology, Karolinska institutet, S‐104 01 Stockholm, Sweden.The present study compares the role of the nucleus accumbens and the striatum, as well as various regions of the striatum, in the ability of intracerebral injections of the dopamine agonists apomorphine and pergolide to elicit rotational behaviour in 6‐hydroxy‐dopamine‐lesioned rats. We found that apomorphine and pergolide elicit rotational behaviour when injected into the denervated striatum, but not when injected into the ipsilateral nucleus accumbens. The striatum seems heterogeneously organized as regards rotational behaviour since maximal‐apomorphine rotation was elicited from the corpus of the striatum as compared to the effects produced by injections into the head and the tail of the striatum. This topographical distribution is similar to the distribution of dopamine‐stimulated cyclic AMP. The pergolide response is more evenly distributed in the striatum. It is suggested that the difference in the topographical distribution of the ability of apomorphine and pergolide to elicit rotational behaviour reflects a regional distribution of dopamine receptors in the striatum of the rat.
Effect of explosive type strength training on isometric force‐ and relaxation‐time, electromyographic and muscle fibre characteristics of leg extensor muscles
Authors: HÄKKUKINEN K. , KOMI P. V. , ALÉN M. 
Published: December 2008

.HÄKKUKINEN, K., KOMI, P.V. & ALÉN, M. 1985. Effect of explosive type strength training on isometric force‐ and relaxation‐time, electromyographic and muscle fibre characteristics of leg extensor muscles. Acta Physiol Scand 125, 587–600. Received 26 January 1985, accepted 9 May 1985. ISSN 0001–6772. Department of Biology of Physical Activity and Department of Health Sciences, University of Jyväskylä, Finland.To investigate the influence of explosive type strength training on isometric force‐ and relaxation‐time and on electromyographic and muscle fibre characteristics of human skeletal muscle, 10 male subjects went through progressive training which included primarily jumping exercises without extra load and with light extra weights three times a week for 24 weeks. Specific training‐induced changes in force‐time curve were observed and demonstrated by great (P < 0.05–0.001) improvements in parameters of fast force production and by a minor (P< 0.05) increase in maximal force. The continuous increases in fast force production during the entire training were accompanied by and correlated with the increases (P < 0.05) in average IEMG‐time curve and with the increase (P < 0.05) in the FT:ST muscle fibre area ratio. The percentage of FT fibres of the muscle correlated (P < 0.05) with the improvement of average force‐time curve during the training. The increase in maximal force was accompanied by significant (P < 0.05) increases in maximum IEMGs of the trained muscles. However, the hypertrophic changes, as judged from the anthropometric and muscle fibre area data, were only slight during the training. It can be concluded that in training for fast force production considerable neural and selective muscular adaptations may occur to explain the improvement in performance, but that genetic factors may determine the ultimate potential of the trainability of this aspect of the neuromuscular performance.
Changes in renal sympathetic outflow during hypotensive haemorrhage in rats
Authors: SKOOG P. , MÅNSSON J. , THORÉN P. 
Published: December 2008

SKOOG, P., MÅNSSON, J. & THORÉN, P. 1985. Changes in renal sympathetic outflow during hypotensive haemorrhage in rats.Acta Physiol Scand125, 655–660. Received 11 February 1985, accepted 13 June 1985. ISSN 0001–6772. Department of Physiology, University of Göteborg, Sweden.The goal of this study was to investigate changes in renal sympathetic outflow during hypotensive haemorrhage. Normotensive Wistar‐Kyoto rats were anaesthetized with chloralose (50 mg kg‐1) and bled to an arterial blood pressure of 50 mmHg for 30 min. Changes in heart rate (HR) and renal nerve activity (RNA) were registered. The hypotensive haemorrhage induced a short‐lasting sympathetic excitation that was followed within 5–10 min by a powerful sympathetic inhibition and bradycardia. The average maximal decrease in sympathetic activity was 65% and the maximal decrease in heart rate was 45 beats min‐1. There was a close correlation between changes in heart rate and renal sympathetic activity.The marked depressor response was due at least in part to activation of vagal afferents because the depressor responses were acutely reversed by bilateral cervical vagotomy.As cardiac afferents are known to be activated by prostaglandins and bradykinins, and these agents are released by myocardial ischaemia, haemorrhage was repeated after use of indomethacin and aprotinin (a protein inhibitor decreasing bradykinin formation), and a marked sympathetic inhibition could still be elicited upon haemorrhage. We therefore suggest that the likely mechanism for activation of the vagal afferents is a squeezing of the myocardium when the heart has to contract around an almost empty chamber. In conclusion, this study demonstrated that hypotensive haemorrhage triggers profound inhibition of RNA in rats and that this sympathoinhibition is mediated primarily by mechanically sensitive cardiac vagal afferents.
Vasoconstrictor effect of high FFA/albumin ratios in adipose tissuein vivo
Authors: BÜLOW JENS , MADSEN JOOP , ASTRUP ARNE , CHRISTENSEN NIELS J. 
Published: December 2008

BÜLOW, J., MADSEN, ASTRUP, A. & CHRISTENSEN, N.J. 1985. Vasoconstrictor effect of high FFA/albumin ratios in adipose tissuein vivo. Acta Physiol Scand125, 661–667. Received 7 December 1984, accepted 17 June 1985. ISSN 0001–6772. Department of Clinical Physiology/Nuclear Medicine, Institute of Medical Physiology C, Copenhagen, Department of Internal Medicine and Endocrinology, Herlev, Denmark.Subcutaneous or perirenal adipose tissue blood flow was measured with the133Xe‐washout technique before and after intravenous injection or infusion of Intralipid* in six anesthetized, otherwise intact mongrel dogs. In four anesthetized mongrel puppies adipose tissue blood flow was measured with the radioactive microsphere method in seven different adipose tissue depots before a bolus injection of Intralipid and at the time after the injection when the thermogenic effect of the Intralipid was maximal. The results showed that the vascular resistance increased in all the examined adipose depots in adult as well as in young dogs after this treatment. The administration of Intralipid did notper seinduce the vasoconstriction. The vasoconstriction took place simultaneously with increasing FFA/albumin molar ratios. The results support our previous findings in perfused fat pads that high molar FFA/albumin ratios increase vascular resistance in adipose tissue and they give further support to our suggestion that this vasoconstriction may be a link in a negative‐feedback mechanism regulating FFA‐mobilization in relation to FFA utilization.
Distribution of ouabain‐binding sites along the dog nephron
Authors: SEJERSTED OLE M. , NICOLAYSEN ANNE , MONCLAIR TOM , NICOLAYSEN GUNNAR 
Published: December 2008

SEJERSTED, O.M., NICOLAYSEN, A., MONCLAIR, T. & NICOLAYSEN, G, 1985. Distribution of ouabain‐binding sites along the dog nephron. Acta Physiol Scand 125, 699–710. Received 2 May 1985, accepted 9 July 1985. ISSN 0001–6772. Institute of Muscle Physiology; University of Oslo, Institute for Experimental Medical Research, Ullevaal Hospital and Institute of Physiology, Oslo, Norway.To quantify the relative amount of ouabain bound to different segments of the nephron after in vivo injection of the drug, an autoradiographic (ARG) study was carried out. After intrarenal injection of [3H]ouabain (120 nmol kg‐1 body wt, 0.9–1.2 Ci mol‐1) to intact kidneys of three anaesthetized dogs, 69–89% of renal Na, K‐ ATPase activity was inhibited. Sodium reabsorption decreased by 21–54%. Sections for ARG were obtained from tissue slices frozen in liquid Freon, freeze‐dried and embedded in resin. Almost no loss of activity occurred during processing and background activity was negligible after 23–36 days' exposure. The density of [3H]ouabain grains per μ2 of tubular walls was 3.8 times higher over medullary ascending limbs of Henle's loop (MAL) and distal cortical tubules (DT) as compared to proximal tubules (PT). In terms of tubular length, the grain density of MAL exceeded that of PT by merely 35% since the cross‐sectional area of the MAL was only 25% of that of PT. In DT, grain density in terms of tubular length was lower than in PT by 10%. Based on previous estimate of the absolute ouabain‐binding capacity in MAL of 60 fmol mm‐1 tubule, the ouabain‐binding capacity in PT and DT would equal 45 and 40 fmol mm‐1, respectively. From composite microphotographs, the relative volume of PT was estimated to be 42% of the total renal volume. This means that 47% of the total renal ouabain‐binding sites are localized to PT, whereas MAL and DT together contain 51 %.