bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Vasoconstrictor Fibre Stimulation on Consecutive Vascular Sections of Cat Small Intestine during Hemorrhagic Hypotension
Authors: Haglund Ulf , Lundgren Ove 
Published: December 2008

AbstractThe effects of the regional sympathetic vasoconstrictor fibres on the consecutive vascular sections of the small intestine of the cat were studied during a 2–2.5 h hemorrhagic hypotension using a plethysmographic technique. The constrictor fibres were intermittently stimulated at 4 Hz before, during and after a hypotensive period at approximately 60 or 40 mm Hg. The nervous responsiveness of the resistance vessels and of the capacitance vessels declined continuously throughout the hypotensive period, the rate of decline being higher the lower perfusion pressure and the lower the arterial blood pH. The capillary filtration coefficient (CFC), reflecting the tonus of the “precapillary sphincters”, was increased during the hypotensive period. Nervous activation reduced CFC throughout the experiments. Tissue volume increased continuously during the latter half of most experiments at 40 mm Hg, probably reflecting a deranged Starling equilibrium across the capillary wall. During the post‐hypotensive control period after a 40 mm Hg hypotension arterial blood pressure fell rapidly. Mucosal ulcerations were regularly found in these animals and the pathogenesis of these lesions is tentatively discussed.
Further Evidence for the Importance of CSF Na+ Concentration in Central Control of Fluid Balance
Authors: Olsson Kerstin 
Published: December 2008

AbstractSlow (0.05 ml/min) infusions of hypo‐, iso‐, and hypertonic solutions of d‐glucose, fructose and sucrose into the CSF of the lateral cerebral ventricle of the goat were found to repress the dipsogenic, antidiuretic and natriuretic responses to intracarotid infusions of hypertonic NaCl. Corresponding intraventricular infusions of slightly hypotonic (0.14 M) NaCl, and of 0.3 M d‐glucose in 0.14 M NaCl did not have this repressive effect. The results are taken as support for the idea that a central receptor system, which is sensitive to variations in the Na+ concentration of the CSF, plays an important role in the control of body fluid homeostasis.
Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle
Authors: Adolfsson Sten 
Published: December 2008

AbstractThe influence of contraction on the content of glycogen in muscle as well as on the activity of the glycogen synthetase enzyme (EC 2.4. 1. 11.)—rate‐limiting for glycogen synthesis—has previously been investigated in vivo. In the present study this influence was studied in vitro, where interference of epinephrine and insulin on the the effects of contraction is more easily excluded. Electrically stimulated intact levator ani muscle preparations from prepubertal rats were used (Arvill, Acta endocr. 1967. 56. suppl. 122). Glycogen content decreased during 15 min of intermittent tetanization (10 slmin). There was no change in synthetase activity during the contractions. For the period following contractions an increase in the per cent active I‐form of the enzyme was found after 1, 2, 10 and 180 min. Resynthesis of glycogen was shown after 30–180 min. An inverse relation between % I‐form and glycogen content was found when data from 1–10 min after contractions were plotted together with the data from unstirnulated muscles. During repeated single twitches (1/s) for 60 min there was an enhanced penetration of xylose‐14C and a higher rate of incorporation of glucose‐14C into glycogen compared to control muscles. The present results are in good agreement with those previously obtained in vivo. Thus, the influence of contractions in vivo could be demonstrated also in vitro.
Antidromic Activation of Renshaw Cells and their Axonal Projections
Authors: Jankowska E. , Smith D. O. 
Published: December 2008

AbstractAntidromic invasion of Renshaw cells following stimulation of their axons was found always to produce only a single spike in contrast to repetitive synaptic discharges. A systematic exploration of the spinal cord in a search for sites from which single Renshaw cells could be activated antidromically revealed that their axons: 1) can project to distances over 12 mm, 2) run in the ventral funiculus. 3) are likely to terminate both within motor nuclei (mainly at short distances) and in an area dorso‐medial and medial to them, and 4) have a maximal conduction velocity of about 30 mls.
The Effect of Insulin on Epinephrine and Glucagon Inactivated Glycogen Synthetase I in the Isolated Perfused Rat Liver
Authors: Hostmark Arne T. 
Published: December 2008

AbstractThe effect of insulin on the reactivation of the epinephrine or glucagon inactivated glycogen synthetase I in the isolated perfused rat liver has been investigated. Livers from fed rats and fasted rats were perfused with Krebs‐Ringer bicarbonate buffer, using either a recirculating or non‐recirculating apparatus. Inactivation of the glycogen synthetase I was observed following th administration of epinehprine or glucagon. It was demonstrated that insulin added 10–15 min after epinephrine or glucagon promoted the reactivation of synthetase I without altering the perfusate glucose concentration. Reactivation by insulin was also observed when livers were perfused with a glucosefree medium in a non‐recirculating system. It is concluded that this action of insulin is not dependent upon the presence of giucose.
A Comparative Study of in vitro Metabolism of Histamine in Various Tissues from Domestic Animals (Cow, Sheep, Horse and Pig)
Authors: Eliassen Knut Arnet 
Published: December 2008

AbstractPreviously, the in vivo metabolism of histamine in domestic animals has been examined. Ruminating and non‐ruminating species seemed to metabolize both parenterally and orally administered Hi in different ways. The present report is concerned with the ability of various tissues from the two types of animal to metabolize histamine. In all species kidney was the most active, and lung one of the least active histamine degrading tissues. In ruminating species, liver seemed to be the most active tissue next to kidney, while intestinal mucosa was of relatively minor importance. In the non‐ruminating species mucosa of the small intestine was the most active tissue after kidney, while liver was less active. Imidazoleacetic acid and an unidentified “metabolite XI” were the 2 main metabolites of histamine in most tissues examined, both at low and high substrate concentrations. The formation of “metabolite XI” was prevented by 10‐4 M aminoguanidine. Addition of S‐adenosylmethionine to the incubation mixtures in‐creased the inactivation rate of histamine in the lung of all species examined, in the intestinal mucosa of the ruminants and in the liver of the non‐ruminants. 1,4‐McH, did not seem to be oxidized to any extent in the methylating tissue.
Effects of Chlorpromazine, Imipramine, and Quinidine on Action Potential and Tension Development in Single Skeletal Muscle Fibres of the Frog
Authors: Anderson K.‐E. 
Published: December 2008

AbstractThe effects of chlorpromazine, imipramine, and quinidine on resting membrane potential, action potential, twitch and tetanic tensions, and on the active state were investigated in single frog skeletal muscle fibres. Chlorpromazine in concentrations 10‐6–10‐5M, and imipramine and quinidine in concentrations 10‐5–5 × 10‐5M, did not affect the resting membrane potential but produced a dose‐dependent decrease in the rate of rise, rate of fall, and overshoot of the action potential. The duration, measured at –50 mV, was prolonged. The drugs potentiated the isometric twitch by increasing the duration of the active state. Tetanic tension was not affected. In high concentrations (chlorpromazine 3 × 10‐5M, imipramine and quinidine > 5 × 10‐5M) the drugs caused a successive widening and decrease of amplitude of the action potential and finally blocked the electrical activity. After a marked initial increase, the peak twitch tension was reduced in parallel with the changes of the action potential. The reduction in twitch amplitude was probably due to incomplete activation of the fibres. The mechanisms of the effects on the excitation‐contraction coupling induced by chlorpromazine, imipramine, and quinidine are discussed.
Differential Effects of Ethyl Alcohol on Retinal Functions
Authors: Bernhard C. G. , Knave B. , Persson H. E. 
Published: December 2008

AbstractThe action of ethyl alcohol on retinal function was analyzed by comparing its effects on the conventional and low‐intensity ERG in the dark‐adapted intact sheep eye. The results showed an increase of the b‐wave and a decrease of the a‐wave amplitude after small doses of alcohol (b.a.c. 20–40 mg%). The low‐intensity ERG, i.e. the electroretinographic responses below b‐wave threshold has recently been shown to consist of a slow, corneanegative receptor response and two fast d.c. responses of opposite polarities from the inner nuclear layer. The negative d.c. response is considered inhibitory in nature and the positive d.c. response excitatory. Administration of alcohol had no effect on the isolated receptor response but elicited an amplitude increase of the positive d.c. response. The results from the low‐intensity ERG experiments suggest the mechanism behind the effects of alcohol on retinal functions to be a selective suppression of the negative d.c. response. Hereby the “controlling” function on the cells generating the positive d.c. response is suppressed, thus “releasing” the positive d.c. response and the b‐wave, which has been shown to be built up by the positive d.c. response. The decrease of the a‐wave appears to be secondary to the increase of the b‐wave, all the more as it was shown that alcohol had no effect on the receptor response. At high blood alcohol con‐centrations, the a‐wave as well as the b‐wave amplitude were found to diminish as an expression for a presumed, general depression of the c.n.s.
Appearance of Red Cells in Peripheral Lymph during Radiation‐Induced Thrombocytopenia
Authors: Aursnes I. 
Published: December 2008

AbstractSome effects of marked thrombocytopenia have been studied in rabbits exposed to whole body irradiation with the ears shielded. In most animals marked thrombocytopenia was present 9–13 days after the irradiation. Lymph samples were obtained by draining a lymph vessel at the base of the ear. In 7 out of 11 rabbits a marked rise in the content of red cells in ear lymph occurred during thrombocytopenia. In the 4 other irradiated rabbits, which developed the same degree of thrombocytopenia, no such red cell increase in the ear lymph occurred. The reason for this is not known. Platelet production may have been resumed at an earlier stage in these 4 animals. The first few platelets produced at the end of the thrombocytopenic period were apparently consumed in repairing the endothelium. This notion is supported by the fact that in some of the 7 rabbits of the former group the erythrocyte‐containing lymph was normalized one day before the number of circulating platelets started to rise. All rabbits showed a steady fall in body weight after irradiation. In the 7 rabbits with red cell increase in lymph, however, a moderate whole body weight gain could be observed at the time with marked thrombocytopenia. This suggests the existence of a slight degree of oedema during thrombocytopenia in these animals.
Histochemical Demonstration of Carbonic Anhydrase Activity in the Human Kidney
Authors: Lönnerholm Gudmar 
Published: December 2008

AbstractThe distribution of carbonic anhydrase activity along the tubules of fresh human donor kidneys, prepared for transplantation, was studied by the histochemical method of Hansson. Enzyme activity was demonstrated in the cells of the convoluted part of the proximal tubule, including the brush border region. The straight part of the proximal tubule contained little or no enzyme, indicating a functional differentiation of the two parts of the proximal tubule. The staining of the thin limb was different in fixed and unfixed tissue. The straight and convoluted parts of the distal tubule, however, showed distinct enzyme activity. In the major part of the collecting duct a mosaic of cells was found; some cells with high and other cells with no or low enzyme activity. In the most distal part near the papilla, however, no enzyme activity was found. The present study shows that carbonic anhydrase is present in those parts of the kidney tubules where there is a postulated role for it. The distribution of the enzyme in the human kidney is similar to that seen in the rat and dog kidney, which suggests a common pattern of urinary acidification in these species.
Urinary Excretion of Noradrenaline in Response to Tilting in Aged
Authors: Hedfors Eva 
Published: December 2008

AbstractUrinary excretion of noradrenaline was measured after 1 h in supine and 1 h tilted head‐up 70 in 8 healthy persons 71–75 years of age. The lack of increase in noradrenaline excretion in response to tilting found in the investigation is probably a normal consequence of an altered reflex circulatory adaptation in this age group.
Mucosal Hemodynamics in the Small Intestine of the Cat during Reduced Perfusion Pressure
Authors: Lundgren Ove , Svanvik Joar 
Published: December 2008

AbstractThis study was performed with an indicator‐dilution technique that allowed quantitative and separate investigation on the cat small intestine, of the “mucosal” as well as of the “villous” intravascular flows and volumes. When reducing arterial inflow pressure from about 100 to about 30 mm Hg “villous” plasma volume and mean transit time increased while “villous” plasma flow remained largely unaltered. Concomitantly, total intestinal blood flow decreased significantly indicating that a larger fraction of total plasma flow was diverted to the villi at low inflow pressure. When intestinal blood flow was reduced by increasing venous outflow pressure villous hemodynamics was largely unaffected. “Mucosal” red cell and plasma flows were affected in the direction of and, generally speaking, in proportion to total intestinal blood flow. These results suggest that the autoregulatory capacity of the villous vessels is larger than that of the vessels in the deeper parts of the mucosa.
Effects of Hernodilution Induced by Hyperoncotic Dextran 40 on Cardiac Contractility
Authors: Pavek Karel 
Published: December 2008

AbstractIn 5 pentobarbital‐anesthetized dogs with autonomous nervous activity blocked with atropine and propranolol, 1 g/kg of dextran 40 as 10% solution was rapidly infused into the right atrium. After dextran, the heart rate was not changed while the mean arterial pressure increased slightly by 5 mm Hg. Cardiac contractility was studied by a continuous display of left ventricular pressure velocity curves. Peak velocity of contractile elements, dP/dt/P estimated at comparable enddiastolic pressure, was not consistently changed after dextran. A higher stroke volume at comparable enddiastolic pressure after dextran suggests improved ventricular function. This might be caused by a decreased aortic impedance. No signs of depressed cardiac contractility occurred after a large dose of dextran 40.
Effects of Adrenaline, Noradrenaline and Isoprenaline on the Electrical and Mechanical Responses of the Guinea‐Pig Vas Deferens to Nerve Stimulation
Authors: Sjöstrand By Nils O. 
Published: December 2008

AbstractSjöstrand, N. O. Effects of adrenaline, noradrenaline and isoprenaline on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation. Acta physiol. scand. 1973. 89. 10–18.The effect of noradrenaline, adrenaline and isoprenaline on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation was studied with the sucrose gap technique. A stimulatory α‐adrenergic effect was found. This was due to a depolarization of the smooth muscle cell membrane. An inhibitory β‐adrenergic effect was observed in some preparations. It consisted of a hyperpolariiSation of the membrane potential and a decrease in size of the excitatory junction potentials. Thirdly, in a few preparations an inhibition of the excitatory junction potentials was seen, which was not a β‐effect but could partly be antagonized by phentolamine. It is suggested that this effect is due to an n‐sympathicomimitic inhibition of the neurotransmission in the vas deferens.
Acid Production in the Isolated Perfused Rat Liver
Authors: Morland By Jorg , Christoffersen Thoralf , Osnes Jan‐Bjorn 
Published: December 2008

AbstractMorland, J., T. Christoffersen AND J.‐B. Osnes. Acid production in the isolated perfused rat liver. Acta physiol. scand. 1973. 89. 61–67.The release and production of organic acids were studied in isolated perfused rat livers. The livers were perfused at different pH with and without ethanol. Liver homogenate pH was measured in certain experiments. The results showed that the basal production of acid by the liver, was greatest in the early phase of perfusion, probably due to the low initial concentration of acid metabolites in the perfusate. The acid production declined when perfusate pH was reduced and increased when perfusate pH was raised. Ethanol treatment (perfusate concentration 30–45 mM) increased the liver acid production. Liver homogenate pH was more reduced after ethanol than after acid addition to the perfusate at the same perfusate pH. It is postulated that ethanol metabolism may influence pH‐sensitive metabolic reactions by the accompanying acid production.
Colonic Motility in the Cat
Authors: Rostad Hans 
Published: December 2008

AbstractRostad Colonic motility in the cat. 1. Extraluminal strain gage technique. Influence of anesthesia and temperature. Acta physiol. scand. 1973. 89. 79‐ 90.A technique for recording colonic motility in vivo with extraluminal strain gage transducers is described. This technique allowed segmental recording of the motility and proved more sensitive than intraluminal pressure devices. The transducers did not appear to interfere with the spontaneous colonic activity. Immediately after laparotomy considerable activity was observed in all parts of the colon. The degree of spontaneous motility varied from animal to animal, and from time to time in the same animal. The colon was seldom quiet unless the anesthesia was deep. Two main types of spontaneous contraction waves were observed: (i) slow waves of 0.5‐2.0 min duration, and (ii) rhythmic waves of a frequency of 4–7 per min. Cooling of the abdominal wall resulted in augmented colonic motility, warming caused relaxation and reduced activity. Variation in body temperature between 3G and 39o did not influence the motility.
Driving Forces over the Peritubular Capillary Membrane in the Rat Kidney during Antidiuresis and Saline Expansion
Authors: Källskog Ö. , Wolgast M. 
Published: December 2008

AbstractKällskog, Ö. and M. Wolgast. Driving forces over the peritubular capillary membrane in the rat kidney during antidiuresis and saline expansion. Acta physiol. scand. 1973. 89. 116–125.The driving forces operative over the renal peritubular capillary membrane has been investigated on a series of male Sprague‐Dawley rats. The hydrostatic capillary pressure was measured by micropuncture technique using a servo‐controlled counter pressure device according to Wiederhielm. The oncotic pressure was estimated from the protein concentration, calculated as the arithmetic mean of the concentration in the proximal end (=plasma concentration/1‐filtration fraction) and that in the distal end of the capillary (= plasma concentration). For estimation of the corresponding interstitial variables a small (50 μm) PCV catheter‐was put into the subcapsular space. The hydrostatic pressure was measured with the same system as for capillaries and the oncotic pressure from the protein concentration in samples withdrawn via the microcatheter. Under control antidiuretic conditions the capillary hydrostatic pressure averaged 11.1 mm Hg and the oncotic 27.7 mm Hg. In the interstitium the corresponding pressures amounted 1.3 mm Hg and 4.0 mm Hg, respectively. In saline expansion the interstitial hydrostatic pressure almost doubled whereas the oncotic pressure decreased towards zero, partly compensating the decrease in net driving force caused by the decreased plasma oncotic pressure following the expansion. Data from lymph flows suggest that the capillary membrane has a small and a large pore system and from these suggestions a model for the regulation nf renal interstitium is presented.
Muscle Spindles in a Flexion Reflex Elicited by Natural Stimulation
Authors: Appelberg Bo 
Published: December 2008

AbstractAppelberg, B. Muscle spin flexions in a flexion reflex elicited by natural stimulation. Acta physiol. scand. 1973. 89. 145–153.In the decerebrate and unanesthetized cat, spinalized at low thoracic level a flexion reflex in the peroneus tertius or the semitendinosus muscle was evoked by natural stimulation of the paw. The behaviour of primary muscle spindle afferents from the muscle under phasic as well as static conditions was studied in the absence of as well as during a reflex contraction. On the basis of the reactions of the spindles to these tests it could be concluded that during a flexion reflex evoked in a natural way static fusimotor neurones are active together with alpha motoneurones. Dynamic fusimotor neurones, on the other hand, do not participate in the reflex.
Colonic Motility in the Cat
Authors: Rostad Hans 
Published: December 2008

AbstractRostad, H. Colonic motility in the cat. V. Influence of telencephalic stimulation and the peripheral pathways mediating the effects. Acta physiol. scand. 1973. 89. 169–181.The cerebral cortex and intracerebral structures were stimulated in lightly anesthetized cats while colonic motility was recorded using extraluminal strain gage transducers. Excitatory colonic responses were produced from the anterior ectosylvian gyrus (the second somatic sensory‐motor area) and from a small zone around the anterior end of the lateral sulcus. These effects were shown to be mediated through the vagal nerves. Colonic inhibition resulted from stimulation of three separate cortical zones, the anterior sigmoid, the orbital and the anterior cingulate gyrl These effects were mediated mainly through the lumbar colonic nerves. Stimulation of the amygdaloid nuclei produced excitatory colonic effects mediated through the lumbar colonic nerves. Inhibitory effects were not obtained from the amygdala. Finally, weak colonic contractions resulted from stimulation of the olfactory bulb and tract and were found to be conveyed through the parasympathetic vagal and pelvic nerves.