bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen dependency of preovulatory follicles from pregnant mare serum gonadotropin‐treated immature rats
Authors: SELSTAM G. , GÅFVELS M. 
Published: December 2008

Oxygen dependency of preovulatory follicles from pregnant mare serum gonadotropin‐treated immature rats. Acta Physiol Scand 130, 483–489. Received 8 January 1987, accepted 27 February 1987. ISSN 0001–6772. Department of Physiology, University of Umei, Sweden.The present study was initiated to test to what extent preovulatory follicles are dependent on oxygen supply for maintaining their response to luteinizing hormone (LH). Female rats of the Sprague‐Dawley strain were injected with 6 IU of pregnant mare serum gonadotropin (PMSG) on their 26th day of life. For in vitro experiments rats were killed 48–52 h after PMSG injection.Preovulatory follicles were dissected free, pre‐incubated for 30 min and then incubated for J h without or with luteinizing hormone (LH, I μg ml‐1 medium) under different oxygen tensions in the gas phase (100,13,6 and o kPa). After incubation the accumulation of progesterone, cyclic‐3′, 5′‐adenosine monophosphate (cyclic AMP) and lactic acid were measured in the incubation media. Follicular adenosine‐5′‐triphosphate (ATP) content was measured in vivo (48–60 h after PMSG injection) immediately after isolation as well as after the incubation. Follicles isolated in vivo, during and after the ovulatory endogenous gonadotropin surge showed a depression in follicular ATP levels compared with levels before, suggesting that gonadotropins stimulate the follicle on the expense of ATP levels during the course of the preovulatory day. During a step‐wise decrease of oxygen tension in vitro the preovulatory follicle maintained its response to LH as measured by progesterone and cyclic AMP accumulation. The preovulatory follicle could apparently compensate by increasing glycolysis, as measured by an increase in lactic acid accumulation. Tissue ATP levels were during these conditions maintained. However, at a near‐total lack of oxygen (approximately o kPa) the progesterone and cyclic AMP response to LH was dramatically lowered as well as ATP levels. Thus, the preovulatory follicle can maintain progesterone production during hypoxia by at least partly compensating energy demand by increasing anaerobic glycolysis.
Changes in elemental composition of human muscle fibres following surgery and immobilization. An X‐ray microanalytical study
Authors: WROBLEWSKI R. , ARVIDSSON I. , ERIKSSON E. , JANSSON E. 
Published: December 2008

Changes in elemental composition of human muscle fibres following surgery and immobilization. An X‐ray microanalytical study. Acta Physiol Scand 130, 491–494. Received 17 December 1986, accepted 16 February 1987. ISSN 0001–6772.King Gustav V Research Institute, Section of Trauma, Department of Surgery, and Department of Clinical Physiology, Karolinska Hospital, Stockholm, Sweden.X‐ray microanalysis of single muscle fibres visualized in the electron microscope has been applied to human muscle biopsies to quantify changes of intracellular elements after knee‐surgery with subsequent immobilization for 6 weeks. An increase of intracellular chlorine (Cl; P 0.001) and of sodium (Na; P 0.1) concentrations were found 1 and 6 weeks post‐surgery. Intracellular potassium (K), phosphorus and sulphur concentrations were not significantly changed. The increased Cl and Na concentrations may be an indication of a decreased activity of the ATPasedependent Na/K‐pump in the sarcolemma and/or of an increased sarcolemmal permeability for Na and Cl.
Motility in auditory sensory cells
Authors: ULFENDAHL M. 
Published: December 2008

Motility in auditory sensory cells. Acta Physiol Scand 130, 521–527. Received 7 January 1987, accepted 27 February 1987. ISSN 0001–6772. Department of Physiology II, Karolinska Institute, Stockholm, Sweden.Three different procedures were employed to induce contraction of isolated cochlear outer hair cells. When cells were permeabilized and exposed to calcium and ATP both a shortening of cell length (14%) and a decrease in cell diameter (12–16%) was observed indicating a longitudinal and a circumferential contraction. When intact cells were treated with positively charged ferritin a shortening of about 10% was observed together with an increase in cell diameter. Application of solutions containing high potassium concentrations gave similar but more rapid results as compared with positively charged ferritin. The observed responses of inner ear sensory cells together with their morphological and immunohistochemical characteristics further support the idea that the hearing organ acts as a motile system.
Source of calcium for contractions induced by depolarization and muscarinic receptor stimulation in rabbit urinary bladder
Authors: BATRA S. , SJÖGREN C. , ANDERSSON K.‐E. , FOVAEUS M. 
Published: December 2008

Source of calcium for contractions induced by depolarization and muscarinic receptor stimulation in rabbit urinary bladder.Acta Physiol Scand130, 545–551. Received 4 December 1986, accepted 20 March 1987. ISSN 0001–6772. Departments of Obstetrics and Gynaecology and Clinical Pharmacology, University of Lund, and AB Leo Research Laboratories, Helsingborg, Sweden.Omission of calcium or the inclusion of lanthanum in the bathing medium resulted in an almost complete inhibition of contractile responses induced by either K+depolarization or carbachol in strips of rabbit urinary bladder. D‐600 inhibited K+‐induced contractions significantly more than carbachol‐induced responses. The influx of45Ca into cells was stimulated both by K+depolarization and carbachol. Over a 2‐min period the increase in46Ca influx induced by high K+and carbachol was 98 and 65%, respectively. Both lanthanum and D‐600 blocked45Ca influx stimulated by either K+depolarization or carbachol. The inhibition of45Ca influx by these calcium‐channel blocking agents, particularly by D‐600, was dependent on the length of exposure. Application of carbachol during45Ca efflux in pre‐loaded muscle strips had no effect on the rate of45Ca efflux. These results indicate that the contractile responses of the urinary bladder to depolarization and to carbachol are highly dependent on an extracellular source of calcium.
The influence of cardiopulmonary receptors on long‐term blood pressure control and plasma renin activity in conscious dogs
Authors: PERSSON P. , EHMKE H. , KIRCHHEIM H. , SELLER H. 
Published: December 2008

The influence of cardiopulmonary receptors on long‐term blood pressure control and plasma renin activity in conscious dogs. Acta Physiol Scand130, 553–561. Received 14 November 1986, accepted 6 March 1987. ISSN 0001–6772. I. Physiologisches Institut, Universität Heidelberg, Federal Republic of Germany.The isolated and combined influence of cardiopulmonary and arterial baroreceptor denervation on long‐term blood pressure (MAP), heart rate (HR), plasma volume (PV) and plasma renin activity (PRA) was studied in 10 conscious, chronically instrumented foxhounds receiving a normal sodium diet. Cardiopulmonary denervation was achieved by surgically stripping both thoracic vagi. Near complete arterial baroreceptor denervation, leaving most cardiopulmonary fibres intact, was made by left vagal deafferen‐tiation which has been shown to eliminate most aortic baroreceptor afferents, and a carotid sinus denervation. Five groups were studied: (I) control (n = 9), (II) cardiopulmonary denervation (n= 5), (III) aortic baroreceptor denervation (n = 5), (IV) arterial baroreceptor denervation (n= 4) and (V) total denervation (n= 6). No changes in PV were observed. Only group V revealed significantly higher levels of MAP (119.5 ± 5.4 us. 100.1±1.6 mmHg; P 0.05), HR (118.1±4.4 us. 87.8 ± 3.7 beats min‐1; P 0.001) and PRA (3.0±0.8 us. 0.9 ± 0.2 ng A1 m‐1 h‐1; P 0.05). It is suggested that the isolated function of either cardiopulmonary or arterial baroreceptors is sufficient to maintain these variables at a normal level. Contrary to the results of other reports the cardiopulmonary receptors do not seem to regulate MAP at a level about which the arterial baroreceptors operate. When both groups of afferents were interrupted MAP, HR and PRA rose to significantly higher levels, implying that cardiopulmonary and arterial baroreceptor afferents interact in a sense of a non‐additive attenuation.
Renal and hormonal responses to atrial natriuretic peptide infusions in goats on high and low sodium intake
Authors: OLSSON K. , ERIKSSON L. 
Published: December 2008

Renal and hormonal responses to atrial natriuretic peptide infusions in goats on high and low sodium intake. Acta Physiol Scand 130, 585–591. Received 7 December 1986, accepted 8 March 1987. ISSN 0001–6772. Department of Animal Physiology, Swedish University of Agricultural Sciences, Uppsala, Sweden and Department of Physiology, College of Veterinary Medicine, Helsinki, Finland.Synthetic atrial natriuretic peptide (ANP) was infused intravenously (I μg min‐1; 60 min) in five goats during two series of experiments. For at least 4 weeks before the ANP infusions the goats received either no salt supplementation (= low sodium diet), or were given 16 g NaCl mixed with the food each day (Na = 274 mmol day‐1; high sodium intake). The goats were changed between the treatments at random. ANP infusions caused diuresis, natriuresis and haemoconcentration during both diets. The urinary Na excretion increased about four‐fold during the high sodium intake, and about 10 times during the low sodium intake. The urinary K excretion increased significantly during the low sodium diet, but decreased slightly during the high sodium intake. During both diets the K excretion became significantly lowered after the infusions. The mean glomerular filtration rate (GFR) was generally lower during the low sodium diet, but increased significantly during ANP infusions on both diets. The GFR returned to baseline immediately after the infusions, in contrast to urine flow and urinary Na excretion. Renal free water clearance increased slightly at the end of the infusion during the low sodium diet, but did not change during the high salt diet. Plasma renin activity (PRA) and plasma aldosterone concentration fell during ANP infusions in goats on the low sodium intake, but did not change significantly during the high sodium diet. These results indicate that the diuresis and natriuresis observed during intravenous ANP infusions in goats are mainly due to increased GFR. The haemoconcentration appears not to be secondary to fluid losses via the kidneys. The results support the concept that changed activity of the renin‐angiotensin‐aldosterone system is not a prerequisite for ANP‐induced natriuresis.
Beta‐endorphin and adrenocorticotropin response to supramaximal treadmill exercise in trained and untrained males
Authors: FARRELL P. A. , KJAER M. , BACH F. W. , GALBO H. 
Published: December 2008

Beta‐endorphin and adrenocorticotropin response to supramaximal treadmill exercise in trained and untrained males. Acta Physiol Scand130, 619–625. Received 18 March 1986, accepted 6 March 1987. ISSN 0001–6772. Institute of Medical Physiology B, University of Copenhagen, Denmark, Department of Human Kinetics, University of Wisconsin‐Milwaukee and Department of Physiology, Medical College of Wisconsin, and Departments of Clinical Chemistry and Neuromedicine, Gentofte Hospital, Denmark.The response of plasma β‐endorphin (β‐EP) and adrenocorticotropin (ACTH) was studied in seven well‐trained (T) young endurance athletes and seven untrained (UT) age‐ and weightdmatched males during treadmill exercise. Subjects ran continuously for 7 min at 60% Vo2max, 3 min at 100% Vo2max and 2 min at 110% Vo2max. Arterialized blood was obtained periodically from a cannulated heated (41 °C) hand vein. Plasma β‐EP was measured by radio‐immunoassay (RIA) which incorporated an antibody that did not cross‐react (< 1.5%) with β‐lipotropin. Plasma β‐EP was similar between groups at rest (T = 4.3±0.8 fmol ml‐1, mean ± SE, UT = 3.3 ± 0.6 fmol ml‐1) and did not change at the 60%±o2max stage. Beta‐endorphin significantly increased at 100% Vo2max with both groups responding similarly. A further increase occurred at 110% Vo2max (T = 10.8 + 2.0 and UT = 6.6+1.0 fmol ml‐1, P 0.05 for between group differences). This between group difference persisted I rnin after exercise when the highest β‐EP levels were reached (T = 18.7 ± 4.7 and UT = 12.8 ± 3.1 fmol ml‐l, P 0.05). Plasma ACTH responses were similar to β‐EP with the highest values (T = 61.5 ±7.2, UT = 45.7 ± 6.8 fmol ml‐1, P 0.05 for between group differences) occurring at I min post‐exercise. A positive correlation, r = 0.85, P 0.05, was found between β‐EP and ACTH using the I rnin post‐exercise values. The enhanced response of β‐EP and ACTH in T may indicate a training‐induced adaptation which increases the response capacity to extreme levels of stress.
Blood flow in skin, subcutaneous adipose tissue and skeletal muscle in the forearm of normal man during an oral glucose load
Authors: BULOW J. , ASTRUP A. , CHRISTENSEN N. J. , KASTRUP J. 
Published: December 2008

Blood flow in skin, subcutaneous adipose tissue and skeletal muscle in the forearm of normal man during an oral glucose load. Acta Physiol Scand 130, 657–661. Received 7 November 1986, accepted 8 March 1987. ISSN 00014772. Department of Clinical Physiology/Nuclear Medicine, Bispebjerg Hospital and Hvidovre Hospital, Department of Medical Endocrinology, Hvidovre Hospital, and Department of Medical Endocrinology, Herlev Hospital, Copenhagen, Denmark.Blood flow to the forearm, and the subcutaneous tissue and skin in the forearm were measured by strain gauge plethysmography, 133Xe‐elimination and Laser Doppler flowmetry during an oral glucose load (I g glucose kg‐I lean body mass) and during control conditions. The forearm blood flow remained constant during both experiments. Glucose induced a two‐fold vasodilatation in subcutaneous tissue. In skin, glucose induced a relative vasodilatation and later a relative vasoconstriction compared with control experiments. When estimated from forearm blood flow and subcutaneous and skin blood flows, muscle blood flow decreased about 20–30% during both experiments. Proximal nervous blockade did not abolish the glucose‐induced vasodilatation in subcutaneous tissue. In the glucose experiment, arterial glucose concentration increased to 7.8 ±1.17 mmol 1‐‐1 30min after the load was given and then decreased to 4.5 ±0.34 mmol 1‐‐1 at the end of the experiment. In the control experiments glucose concentration was constant. Arterial noradrenaline concentration increased significantly from 1.0±0.13 to about 1.5±0.3 nmol 1‐‐1 120 min after glucose and remained at this level during the experiment. Similarly adrenaline increased from 0.16 ±0.11 to about 0.4 ±o.16 nmol I‐1 180 min after glucose. It is hypothetized that the vasodilating effect of glucose in subcutaneous tissue is secondary to metabolic events connected to glucose uptake and energy deposition in adipose tissue.
Isoflurane hyperpolarizes neurones in rat and human cerebral cortex
Authors: BERG‐JOHNSEN J. , LANGMOEN I. A. 
Published: December 2008

Isoflurane hyperpolarizes neurones in rat and human cerebral cortex. Acta Physiol Scand130, 679–685. Received 19 January 1987, accepted 10 March 1987. ISSN 0001–6772. Institute for Experimental Medical Research and Department of Neurosurgery, Ullevål University Hospital and Department of Neurosurgery, National Hospital, Rikshospitalet, Oslo, Norway.The effect of the anaesthetic gas isoflurane was studied by intracellular recordings in neurones from rat hippocampal cortex and neurones from human neocortex in vitro. Anaesthetic concentrations of isoflurane abolished spontaneous activity and reduced synaptically evoked activity without rendering individual cells inexcitable or preventing evoked synaptic activity to increased afferent input. Induced epileptiform activity was not observed. Isoflurane reversibly hyperpolarized the cell membrane in a dose‐dependent manner, isoflurane 1.5, 3 and 5% causing 4±1, 6 ± 2 and 8±2 mV (mean ± SD) hyperpolarization, respectively. The hyperpolarization was accompanied by a reduction in the input resistance, 18 ± 3 % for 3 % isoflurane. The effects remained unchanged after synaptic transmission was blocked. Five experiments with intracellular recordings from human cortical neurones in vitro showed identical results.
Functional development of the visual system in normal and protein‐deprived rats. V. Specific cortical response and repetitive stimulation in adult rats
Authors: SJÖSTRÖM A. , CONRADI N. G. , ANDERSSON S. A. 
Published: December 2008

Functional development of the visual system in normal and protein deprived rats. V. Specific cortical response and repetitive stimulation in adult rats. Acta Physiol Scand130, 705–711. Received 29 December 1986, accepted 16 March 1987. ISSN 0001–6771. Departments of Physiology and Pathology, University of Göteborg, Sweden.Recent studies on the specific visual system have indicated that early induced protein deprivation results in an impaired transmission from cell to cell in the cortex. To further investigate cortical mechanisms the response to repetitive light flashes and to electrical stimulation of the optic tract (OT) and the dorsal lateral geniculate nucleus (dLGN) were examined. The first potential of the surface visual evoked response (VER) and the monosynaptic response to OT and dLGN stimulation showed similar sensitivity to repetitive stimulation in C and PD rats. In PD rats later activity was significantly more sensitive to repetitive stimulation than in controls. By using paired stimuli with a short inter‐stimulus interval, similar inhibitory mechanisms in PD and C rats were demonstrated. The results support the view that protein deprivation results in impaired cortical synaptic activation. The results are discussed in relation to previously described impairment at the cortical level in malnourished animals.
Functional development of the visual system in normal and protein‐deprived rats. VI. Evoked responses in adult rats, protein deprived in early life and nutritionally rehabilitated from weaning
Authors: SJÖSTRÖM A. , CONRADI N. G. 
Published: December 2008

Functional development of the visual system in normal and protein‐deprived rats. VI. Evoked responses in adult rats, protein deprived in early life and nutritionally rehabilitated from weaning. Acta Physiol Scand130, 713–721. Received 29 December 1986, accepted 16 March 1987. ISSN 0001–6772. Departments of Physiology and Pathology, University of Göteborg, Sweden.Previous studies have shown an increase in latency of the visual evoked response (VER) recorded from the cortical surface of adult rats subjected to protein deprivation (PD) during pre‐ and postnatal development. This alteration has been shown to originate mainly from the cortex itself. In the present study the possibility of normalizing such VER alterations by nutritional rehabilitation after early protein deprivation (R‐PD) was investigated. Male rats were subjected to pre‐ and early postnatal protein deprivation through their mothers. Nutritional rehabilitation was started from weaning. The rats gained weight rapidly compared with rats subjected to protein deprivation throughout postnatal development but never reached the weight of controls (C) of the same age. Food consumption in relation to body weight was similar to that of controls. Rehabilitation continued until adult age when neurophysiological experiments were performed. The VER recordings from the dorsal lateral geniculate nucleus (dLGN) showed latencies similar to those reported previously for adult C and PD rats. The latencies of onset and first peaks of the cortical response recorded from the surface were increased by 5–6 ms in R‐PD compared with C rats and hence similar to the latencies of adult PD rats. Intracortical responses to electrical stimulation in the dLGN were also similar to those of adult PD rats showing an normal onset latency but an increased latency of the peaks of the monosynaptic and late responses compared with C rats. The present results imply that the increased VER latencies noted in adult PD and R‐PD rats are due to changes installed by protein deprivation during early development since they can not be reversed by nutritional rehabilitation starting at weaning.
Small intestinal fluid absorption in the rat during haemorrhage and its importance for plasma refill
Authors: REDFORS S. 
Published: December 2008

Small intestinal net fluid absorption and its importance for plasma volume restitution during a slow, stepwise haemorrhage was studied in rats. A continuous administration of a Krebs–glucose solution into the intestinal lumen increased the tolerated maximal bleeding volume from 31 to 70% of initial total blood volume. The ‘small intestinal’ autotransfusion rate, i.e. the rate of fluid mobilized from the intestinal lumen into the vascular compartment, was calculated to 2.3 ml h‐1 too cm‐2 small intestinal serosal surface. ‘Small intestinal’ autotransfusion is proposed to be an important mechanism in the defence line against hypovolaemia.Haemorrhage induced a 40% increase in small intestinal net fluid absorption. This increase was abolished after pretreatment with Captopril, an angiotensin‐converting enzyme blocker. Post‐ganglionic denervation of the small intestine reduced, but did not abolish, the stimulatory effect of haemmorrhage on net fluid absorption. These results indicate that both a direct nervous component and the renin‐angiotensin system are of importance for the increase in small intestinal net fluid absorption observed after haemorrhage.
Course and mode of action of descending system conveying nucleus raphe magnus induced inhibition of flexion reflex in rats
Authors: JØIRUM E. , SHYU B. C. 
Published: December 2008

In lightly anaesthetized rats, the latencies and magnitudes of heat‐evoked withdrawal reflexes from the hindlimb were measured electromyographically. Low‐intensity (20–50 μA) stimulation of the nucleus raphe magnus (NRM) resulted in an inhibition of the flexion reflex (commonly referred to as analgesia) as evidenced by increased latency and decreased amplitude. The effect lasted for several minutes after the stimulation was terminated. Following lesions of the dorsolateral funiculus (DLF) at the neural thoracic levels 7–8, baseline latencies were reduced and the effect of the NRM stimulation was abolished. Lesions of the DLF at lumbar level 1 resulted in unaltered baseline latencies with persistence of the inhibitory effect of NRM stimulation.The results of the present experiment show that pathways exerting a tonic inhibition of the withdrawal reflex, and mediating the effect of electrical stimulation from the NRM, descend in the DLF at the thoracic level of the spinal cord. At the lumbar level, there is a shift away from the DLF.The antinociceptive effect of 20 μA NRM stimulation was partly reduced by pretreatment with the serotonin synthesis inhibitor para‐chlorophenylalanine (PCPA) or the opiate naloxone (1 mg kg–1 i.v.). In animals pretreated with PCPA, naloxone (1 mg kg–1 i.v.) completely abolished the analgesic effect of the stimulation. Thus, both serotonergic and opioid systems may be implicated in mediating the analgesia. With 50 μA stimulation the same treatment only partly attenuated the NRM‐induced analgesia, indicating an additional non‐serotonergic and non‐opioid mechanism which requires a higher current intensity for its activation.