bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the capacity of the β‐oxidation of palmitate and palmitoyl‐esters in rat liver mitochondria
Authors: Farstad Mikael , Berge Rolf 
Published: December 2008

AbstractThe β‐oxidation of palmitate, palmitoyl‐CoA and palmitoyl‐L‐carnitine proceeded at a high rate in isolated rat liver mitochondria. At high concentrations (100 nmol/mg protein) the oxidation of palmitate and palmi‐toyl‐CoA was only partly carnitine dependent. All substrates were most rapidly oxidized in the presence of oxaloacetate and state 3 conditions. Succinate inhibited β‐oxidation especially in state 4 conditions. β‐Oxidation was faster in hypotonic than in isotonic medium both in state 3 and state 4 conditions. Hyper‐tonicity inhibited β‐oxidation. The initial formation of palmitoyl‐CoA from palmitate, CoA and ATP was faster than the oxidation of palmitate under identical conditions. The presence of bovine serum albumin inhibited the β‐oxidation, especially with palmitoyl‐CoA or free palmitate as the substrates. Mitochondria contain a palmitoyl‐CoA hydrolase which may influence the available intramitochondrial palmitoyl‐CoA. The present results demonstrate no single rate limiting step in the β‐oxidation in vitro. Both the NADH/ NAD ratio, competition for the respiratory chain, the level of ADP, binding of palmitoyl‐CoA to extramitochondrial protein, and possibly intramitochondrial hydrolysis of palmitoyl‐CoA all seem to influence the rate of β‐oxidation in vitro. It is suggested that in vivo the most important factor is the availability of acyl‐CoA to the outer carnitine palmitoyl‐transferase of the mitochondria.
Adjustments of hepatic and small intestine blood flow on selective vasoconstrictor fibre stimulation
Authors: FASTH S. , HULTÉN L. , NORDGREN S. 
Published: December 2008

FASTH, S., HULTÉN, L. & NORDGREN, S.: Adjustments of hepatic and small intestinal blood flow on selective vasoconstrictor fibre stimulation. Acta Physiol Scand 1980, 110:343–350. Received 16 Jan. 1980. ISSN 0001–6772. Department of Surgery II, Sahlgrenska sjukhuset, University of Goteborg, Sweden.The mutual changes in hepatic and small intestinal blood flow on selective nervous stimulation of the periarterial vasoconstriction fibres, were studied in anaesthetized cats. Occlusion of the hepatic artery did not change portal blood flow, whereas occlusion of superior mesenteric blood flow caused a significant increase in hepatic arterial flow. Stimulation of the hepatic sympathetic nervous supply caused a phasic blood flow response with a marked transient peak flow reduction of hepatic arterial blood flow. The magnitude of the peak response varied with the frequency of the stimulation. Despite continuous stimulation the first phase went over into a second phase of less pronounced vasoconstriction. This “steady state” blood flow, was maintained at about 20% below the control level, irrespective of stimulation frequency. Corresponding in time with the peak vasoconstriction there was a transient increase of portal pressure. Sympathetic nerve stimulation increased portal pressure even on occlusion of the hepatic artery. Stimulation of the mesenteric sympathetic nerves evoked the characteristic transient peak vasoconstrictor response consisting of two phases, a brief intense peak resistance response followed by a second phase of less pronounced but generally well maintained constriction. Simultaneously a slight reduction of portal pressure and hepatic arterial vascular resistance was regularly seen. In contrast to the observations in the hepatic arterial circuit the magnitude of this “steady state” blood flow in the small intestine was dependent on the rate of the stimulation, however. On simultaneous stimulation of the hepatic and mesenteric sympathetic nerves the hemodynamic responses were largely the same as when these nerves were stimulated separately. The portal pressure affecting mean capillary pressure in the intestine differed, however. Small and variable pressure changes were followed by rapid return towards control and during steady state it did not differ from the prestimulatory level.This investigation was supported by grants from the Swedish Medical Research Council (No. 17X‐3117), from the Faculty of Medicine, University of Goteborg, The Swedish Society of Medical Sciences, from Goteborgs Likaresallskap and Assar Gabrielsson's Fund.
Autonomic nervous control of endometrial secretion in the guinea pig
Authors: HAMMARSTRÖM MARGARETA 
Published: December 2008

HAMMARSTRÖM, M. Autonomic nervous control of endometrial secretion in the guinea pig. Acta Physiol Scand125, 461–469. Received 22 March 1985, accepted 6 May 1985. ISSN 0001–6772. Department of Physiology I, Karolinska Institute, Stockholm, Sweden.Secretory responses of the guinea pig endometrium to field stimulation of nerves and/or drugs were studied throughout oestrous cycle. Secretory responses are dependent on the hormonal state of the animals and are seen at oestrus, metoestrus and at implantation time. The cholinergic nature of the secretory innervation was confirmed. Optimal secretory response was found at 0.5 or 1 Hz continuous stimulation. Adrenergic inhibition was revealed at metoestrus (day 3–5), The α‐adrenergic inhibitory influence had its optimal frequency at 0.5 Hz. The inhibition seemed to be both prejunctional and postjunctional. VIP increased endometrial secretion, the effect was probably preterminal. Burst stimulation at any frequency gave less (or no) secretory responses under these experimental conditions. The complex organization of the endometrial innervation is apparent.
Effects of amrinone on the contractile behaviour of frog striated muscle fibres
Authors: MÅNSSON ALF , EDMAN K. A. P. 
Published: December 2008

MANSSON, A. & EDMAN, K. A. P. 1985. Effects of amrinone on the contractile behaviour of frog striated muscle fibres. Acta Physiol Scand125, 481–493. Received 18 March 1985, accepted 10 May 1985. ISSN 0001–6772. Department of Pharmacology, University of Lund, Sweden.The effects of amrinone (0.005–2.1 mM) were studied on isolated single muscle fibres of the frog (0.6–4.3 °C). In the concentrations used amrinone potentiated the isometric twitch, increased the initial rate of force development and prolonged the time to peak twitch force and the time from peak force to half relaxation. There was a moderate but statistically significant (P < 0.001) enhancement of the maximum tetanic force and a marked slowing of the relaxation phase of the tetanus. Amrinone depressed the velocity of unloaded shortening by 33 ± 2% (mean ± SE, π= 6) and reduced the curvature of the force‐velocity relation leading to an increase of a/PO in Hill's (1938) hyperbolic equation. In accordance with the effects of amrinone on the force–velocity relation, there was a decrease in the rate of redevelopment of force after the fibre was released to zero tension during the tetanus plateau. The evidence suggests that the drug affects the contractile properties of frog muscle fibres by two different mechanisms: (1) amrinone affects the excitation–contraction coupling causing enhanced calcium release in response to membrane excitation and (2) amrinone exerts a direct effect on the kinetics of turnover of the myosin cross‐bridges. The latter aspect of the drug effect was evaluated in terms of A. F. Huxley's (1957) cross‐bridge model by means of a computer program.
Effects of 5‐hydroxytryptamine and related agents on endothelial cell oxidative metabolism in vitro
Authors: KJELLSTRÖM B. THOMAS , ÖRTENWALL PER , RISBERG BO 
Published: December 2008

KJELLSTRÖM, B.T., ÖRTENWALL, P. & RISBERG, B. 1985. Effects of 5‐hydroxytryptamine and related agents on endothelial cell oxidative metabolism in vitro. Acta Physiol Scand 125, 501–504. Received 10 April 1985, accepted 21 May 1985. ISSN 0001–6772. Department of Surgery I, University of Göteborg, Sweden.A recently described microrespirometric method was used to determine the influence of 5‐hydroxytryptamine (5‐HT), nialamide, imipramine and ouabain alone and in combinations on oxidative metabolism in monolayer cultures of endothelial cells from the rat pulmonary artery. It was found that exposure to 5‐HT increased oxygen uptake in the cultures, while imipramine or ouabain decreased respiration; nialamide had no obvious effect. When used in combinations, the effect of ouabain or imipramine dominated over the 5‐HT effect.The explanation for this 5‐HT stimulating effect on endothelial cell oxidative metabolism, previously undescribed, is suggested to be that 5‐HT exposure stimulated individual cells to contract. This active contraction resulted in an increased energy demand reflected in elevated oxygen consumption, an effect inhibited by ouabain or imipramine.
Effects of adrenaline infusion on cAMP and glycogen phosphorylase in fast‐twitch and slow‐twitch rat muscles
Authors: CHASIOTIS D. 
Published: December 2008

CHASIOTIS, D. 1985. Effects of adrenaline infusion on cAMP and glycogen phosphorylase in fast‐twitch and slow‐twitch rat muscles. 1985 Acta Physiol Scand125, 537–540. Received 15 February 1985, accepted 28 May 1985. ISSN 0001–6772. Department of Clinical Chemistry II, Karolinska Institutet, Huddinge University Hospital, Huddinge, Sweden.This study investigated the effect of adrenaline infusion on the cAMP content, glycogen phosphorylase activity and the rate of glycogen breakdown in rat extensor digitorum longus (EDL) and soleus muscles. Adrenaline was constantly infused in a dose of 0.15 μg kg‐1 body wt min‐1. The cAMP content increased approximately 2.8‐fold in both muscles after 2 min of infusion. Phosphorylase a 4‐ b activity was six times higher in fast‐twitch muscle (EDL) than in slow‐twitch (soleus) and remained unchanged during the infusion. Phosphorylase a activity increased by 8.4‐fold in EDL and 2.4‐fold in soleus muscles during the infusion period. Glycogen content decreased in EDL muscle by 10% whereas no change was observed in soleus. It is concluded that β‐adrenergic stimulation by adrenaline results in a similar cAMP increase in both muscles. The low rate of glycogen breakdown in EDL and the unchanged content of glycogen in soleus muscle suggest that cAMP mediated transformation of phosphorylase b to a in itself is not adequate for a rapid glycogenosis in muscle phosphorylase.
Interstitial fluid pressure in the isolated perfused rabbit lung
Authors: WIIG HELGE , OPDAHL HELGE , NICOLAYSEN ANNE , NICOLAYSEN GUNNAR 
Published: December 2008

WIIG, H., OPDAHL, H., NICOLAYSEN, A. & NICOLAYSEN, G. 1985. Interstitial fluid pressure in the isolated perfused rabbit lung. Acta Physiol Scand 125, 601–607. Received 10 March 1985, accepted 9 May 1985. ISSN 0001–6772. Department of Physiology, University of Bergen and Institute of Physiology, University of Oslo, Norway.Interstitial fluid pressure was measured in nine isolated perfused rabbit lungs with the servonull micropipette method. Bevelled glass micropipettes, with tip diameter 2–6 μm (o.d.) were inserted 2–6 mm into the left lung. At alveolar pressures of 3 to 5 cm H2O we found mean interstitial fluid pressures of 1.0 (SD 1.0) and 1.6 (SD 1.0) cm H2O relative to pleural pressure in the upper (n = 19) and lower (n = 21) lobes respectively. The vertical distance between the measuring sites in the upper and lower lobes was about 3 cm. Net filtration caused by elevated left atrial pressure caused practically no change in interstitial fluid pressure. Increased alveolar pressure either increased or decreased interstitial fluid pressure. The measured pressures probably represent interstitial fluid pressure in alveolar junctions or in the interstitium around small pulmonary arteries or veins. We conclude that interstitial fluid pressure in these sites is between alveolar and pleural pressure, and that it is only moderately affected by changes in alveolar pressure. The interstitial compliance appears to be high and there seem to be little or no vertical gradients in interstitial fluid pressure within the lung.
Plasma lipoprotein distribution, faecal cholesterol excretion, and activities of lipoprotein lipase, hepatic lipase and lecithin:cholesterol acyltransferase in rats fed diets rich in sucrose or sunflower oil
Authors: HAUG ANNA , HØSTMARK ARNE T. , SPYDEVOLD ØYSTEIN 
Published: December 2008

HAUG, A., HØSTMARK, A.T. & SPYDEVOLD, Ø. 1985, Plasma lipoprotein distribution, faecal cholesterol excretion, and activities of lipoprotein lipase, hepatic lipase, and lecithin: cholesterol acyltransferase in rats fed diets rich in sucrose or sunflower oil. Acta Physiol Scand 125, 609–617. Received 10 January 1985, accepted 10 May 1985. ISSN 0001–6772. Department of Preventive Medicine and Institute for Medical Biochemistry, University of Oslo, Norway.Plasma HDL2 has been suggested to carry cholesterol to the liver for subsequent excretion in the bile and faeces. The enzymes lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT) have been implicated in the centripetal cholesterol transport. Activities of these enzymes, the amount of faecal cholesterol excretion and the level of plasma lipoproteins were determined in male rats fed for 4 weeks on purified diets in which the sunflower oil: sucrose ratio was either 0.03 (group a) or 1.01 (group b). Whole plasma triacylglycerols (TG), unesterified cholesterol (UC) and phospholipids (PL) were highest in group (a). The concentration of cholesteryl esters (CE) was similar in the two groups. Protein, TG and UC of VLDL, and TG, UC, CE and PL of HDL2 were higher in group (a) than in group (b). The HDL3‐protein and TG were lowest in group (a). Thus, total weight of VLDL and HDL2 were increased, and HDL3 reduced in group (a), which had also increased activities of HL and adipose tissue LPL. Activity of LCAT was lower, and faecal excretion of cholesterol was reduced by about 50% in group (a) compared to group (b). Accordingly, in the rat increased plasma levels of HDL2 are not necessarily indicative of increased faecal cholesterol excretion.
Influence of thyroid hormones on transport function and Na+‐K+‐ATPase activity in the rat choroid plexus
Authors: LINDVALL‐AXELSSON M. , HEDNER P. , OWMAN CH. , WINBLADH B. 
Published: December 2008

LINDVALL‐AXELSSON, M., HEDNER, P., OWMAN, CH., & WINBLADH, B. 1985. Influence of thyroid hormones on transport function and Na+‐K+‐ATPase activity in the rat choroid plexus. Acta Physiol Scand 125, 627–632. Received 11 February 1985, accepted 28 May 1985. Departments of Histology and Internal Medicine, University of Lund, Lund, and Department of Pediatrics, Sachs' Children Hospital, Karolinska Institute, Stockholm, Sweden.The sympathomimetic stimulation of choroid plexus transport and secretion in rat seems to be mediated by β‐adrenergic receptors. In the present report the effect of induced changes in thyroid function on transport mechanisms in the rat choroid plexus was studied. Following induction of hyperthyroidism (treatment with T3 for 10 days) the tissue/medium ratio (T/M) for choline uptake in choroid plexus in vitro decreased significantly by 68%. The Na+‐K+‐ATPase activity showed a statistically significant increase of about 16%. Also following cervical sympathectomy, T3 caused a reduction of the T/M for choline, to the same level as in the non‐sympathectomized animals, while the effect of T3 on the Na+‐K+‐ATPase activity was changed into a 22% decrease. Hypothyroidism (administration of PTU in the drinking water) had little or no effect on the uptake and accumulation of choline in the choroid plexus. The Na+‐K+‐ATPase activity was reduced by 40%, in contrast to the stimulating effect of T3. There is, hence, reason to believe that the transport of choline in the choroid plexus is only partly regulated by adrenergic mechanisms acting via Na+‐K+‐ATPase. The major effect of T3 on the choline uptake may be exerted by a mechanism different from the ATPase activity and not involving adrenergic receptors.
Effects of intra‐arterially infused adenosine triphosphate (ATP) on release of vasoactive intestinal polypeptide (VIP) from the gastrointestinal tract of the cat
Authors: SJÖQVIST A. , FAHRENKRUG J. , HEMLIN M. , JODAL M. , LUNDGREN O. 
Published: December 2008

SJÖQVIST, A., FAHRENKRUG, J., HEMLIN, M., JODAL, M. & LUNDGREN, O. 1985. Effects of intra‐arterially infused adenosine triphosphate (ATP) on release of vasoactive intestinal polypeptide (VIP) from the gastrointestinal tract of the cat.Acta Physiol Scand125, 693–698. Received 28 February 1985, accepted 26 June 1985. ISSN 0001–6772. Department of Physiology, University of Göteborg, Sweden.Close i.a. infusions of ATP were made to the stomach, the small intestine or the colon in the cat. The vascular reactions were followed by recording arterial pressure and total venous outflow continuously and the release of VIP was estimated intermittently from arterio‐venous concentration differences and blood flow. In all experiments ATP caused a vasodilatation and an increased release of VIP into blood. In control experiments it was shown that evoking a vasodilatation of the same magnitude by close i.a. infusions of isoprenaline or papaverine did not evoke any similar release of VIP. It is concluded that the infused ATP released VIP from the different parts of the gastrointestinal tract. Possible mechanisms underlying this effect are tentatively discussed.
Turnover rate of interstitial albumin in rat skin and skeletal muscle. Effects of limb movements and motor activity
Authors: REED ROLF K. , JOHANSEN STEINAR , NODDELAND HARALD 
Published: December 2008

REED, R.K., JOHANSEN, S. & NODDELAND, H. 1985. Turnover of interstitial albumin in rat skin and skeletal muscle. Effects of limb movements and motor activity. Acta Physiol Scand 125, 711–718. Received 6 December 1984, accepted 19 July 1985. ISSN 0001–6772. Department of Physiology, University of Bergen, Bergen, Norway.Fractional removal rate (FRR) of radioactive‐labelled human serum albumin (I‐HSA) injected subcutaneously or intramuscularly was determined by external gamma‐detecting equipment. Radioactivity over the injection site fell monoexponentially during registration periods up to 6 h. The FRR was calculated as the turnover rate constant of the radioactivity removal. The FRR fell into one of two ranges: in anaesthetized rats FRR was 0.02–0.03 h‐1, and in awake and freely moving rats FRR was 0.08–0.11 h‐1. Inawake rats, FRR was similar during day and night (spontaneous motor activity is four times higher during the night). Passive limb movements at 1 Hz in anaesthesia increased FRR in skin to that in awake rats, while FRR in skeletal muscle was unchanged. Immobilization resulted in FRR similar to that in anaesthesia. Interstitial albumin mass did not change during 6 h of anaesthesia. It is concluded that the observed FRR reflects steady state changes in albumin turnover. In the awake and freely moving rats at least 3/4 of the removal of albumin is by the lymphatics. Calculated lymph flow was 10 μl g‐1 h‐1 and 40 μg‐1 h‐1 in skeletal muscle and skin respectively with corresponding figures during anaesthesia of 3 μg‐1 h‐1 and 10 μg‐1 h‐1 respectively.
The role of prostanoids in the feline intestinal vascular and central haemodynamic responses to i.v. infusion of live E.coli
Authors: SCHÜTZER K.‐M. , HAGLUND U. , FALK A. 
Published: December 2008

The role of prostanoids in the feline intestinal vascular and central haemodynamic responses to i.v. infusion of liveE. coli. Acta Physiol Scand130, 359–366. Received 23 July 1986, accepted 11 February 1987. ISSN 0001–6772. Departments of Surgery, East Hospital, Göteborg, and General Hospital, Malmö, Sweden.Bacterial infusion in the cat, causing experimental septic shock, induces an early vascular response mainly characterized by pulmonary hypertension and intestinal vasocon‐striction. Prostanoids are held to be important mediators of the pulmonary vascular reaction. This study was performed to explore the involvement of prostanoids in the central haemodynamics and the small intestinal vascular reactions in experimental septic shock. Aortic blood pressure was continuously monitored, as were aortic blood flow, the pressure in a. pulmonalis and the small intestinal venous outflow. All cats (n= 24) were given liveE. coli(1010ml‐1) as a continuous intravenous infusion. One series was pretreated with indomethacin, another with UK‐38,485, a specific thromboxane A, synthetase inhibitor, and a third series served as untreated control. The pulmonary hypertensive response was clearly attenuated in the two pretreated series, in fact abolished in the one given UK‐38,485. The early intestinal vasoconstriction was eliminated in the two pretreated series. Later during bacteraemia, when untreated and indomethacin‐pretreated cats showed intestinal vasoconstriction, UK‐38–485‐pretreated animals kept intestinal blood flow within the preseptic range. These data suggest that in the cat, thromboxane A, is the prostanoid mediating the vascular reactions, not only in the lung but also in the small intestine.
Prevention of ischaemic acute renal failure with superoxide dismutase and sucrose
Authors: BAYATI A. , HELLBERG O. , ODLIND B. , WOLGAST M. 
Published: December 2008

Prevention of ischaemic acute renal failure with superoxide dismutase and sucrose. Acta Physiol Scand 130, 367–372. Received 24 September 1986, accepted 10 February 1987. Department of Physiology and Medical Biophysics, University of Uppsala, Sweden.The preventive effects of intravenously administered superoxide dismutase (SOD) and of SOD combined with sucrose on acute renal failure were investigated in rat kidneys exposed to 45 min of warm ischaemia. Superoxide dismutase (20 mg) given just before primary ischaemia and in the early recirculation phase was found to ameliorate the red cell aggregation in the renal medulla, in particular, in the inner stripe of the outer zone the volume of trapped red cells decreased from 11.2 ± 1.6% in untreated animals to 0.02 ± 0.001%, thus allowing improved restoration of medullary blood flow. This was also accompanied by an expected restoration of the urine osmolality reaching almost 400 mOsmkg‐1 after administration of SOD + sucrose. Superoxide dismutase also restored the capillary macromolecular permeability as evidenced by normalization of plasma to lymph transport of proteins. Micropuncture studies showed that in ischaemically damaged but untreated kidneys the tubules were obstructed and that the proximal tubular pressure rose to such a level that the net driving force for filtration approached zero. This explains the marked decrease in glomerular filtration rate (GFR) from a normal value of about 1 ml min‐1 to 0.01 ± 0.02 ml min‐1. After treatment with SOD the tubules were still largely obstructed, resulting in a depression of the net driving force and a decrease in single nephron glomerular filtration rate (SNGFR) to about 11 nl min‐1, that is, to only 25% of the normal SNGFR. The total filtration was 0.09 ± 0.04 ml min‐1. When sucrose (2 ml of a 12% sucrose‐Ringer solution) was given in addition to SOD, with the aim of preventing cellular swelling, rapid wash‐out of rejected cells and cell debris into the urine was observed. The obstructions were eliminated and the free‐flow proximal tubular pressure was next to normal. The resulting SNGFR was about 30 nl min‐1 and the total filtration 0.29 ± 0.06 ml min‐1.