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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 367 (1976), S. 37-42 
    ISSN: 1432-2013
    Keywords: Acetylcholine ; Atropine ; Inderal ; Sympathetic system ; Phosphorylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Phosphorylase activity was found to increase 2-fold as compared with the control value (79% and 39% respectively) within the first 2–3 s of the vasomotor effect elicited in the skeletal muscle by sympathetic stimulation. Phosphorylase activity was still high during the period of maximum blood flow, although to a lesser extent (54% and 45%). During the phase of restoration of the initial rate of blood flow the values of phosphorylase activity were the same in the experimental and the control sample. The AMP content did not increase with the initiation of the vasomotor effect, and this fact suggests that the increase in phosphorylase activity is due to an increase in phosphorylase “a” rather than to the activation of phosphorylase “b” by AMP. Atropine blocks both the dilator effect and phosphorylase activation elicited by sympathetic stimulation. Acetylcholine, injected intraarterially or added to a muscle homogenate, increases phosphorylase activity. It is concluded that acetylcholine, released by sympathetic nerve endings, performs a second mediator function, that of activating anaerobic metabolism in the skeletal muscle. The two mediator functions of acetylcholine seem to be spatially delimited.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2013
    Keywords: Sympathectomized rats ; Total peripheral resistance ; Structural component of resistance ; Vasodilator reserve
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study showed that arterial blood pressure of chemically sympathectomized rats (SR) was decreased, whereas heart rate was increased relative to controls. The cardiac output in SR was higher than that in intact animals (by 36% under urethane anaesthesia and by 80% without anaesthesia). The total peripheral resistance of SR was 1.7 times less than normal, although the magnitude of the structural component of resistance was increased. The half-time clearance of133Xe from skeletal muscle during motor nerve stimulation was greater in SR than in intact rats by a factor of 2. It is concluded that the number of small resistance vessels in SR is low, while the lumen of individual vessles is greater than in controls, thus giving rise to an insufficient “vasodilator reserve”.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 392 (1982), S. 394-398 
    ISSN: 1432-2013
    Keywords: Cholinergic vasodilatation ; Acetylcholine ; Atrophine ; Osmolality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The arterio-venous difference in the osmolality of blood plasma of cat m. triceps surae was studied during sympathetic cholinergic nerve excitation. The vasodilatation was induced by stimulation of hypothalamus or the sympathetic chain, the latter after α-adrenoceptor blockade. The vasodilator effect induced by intraarterial injection of acetylcholine was also tested. In all cases studied the vasodilatation was associated with an increase in osmolality (on the average by 10 mOsm/kg H2O with a maximum at the 30–40th s after the beginning of stimulation). Atropine (0.1 mg/kg) considerably decreased the vasodilator effect elicited by hypothalamic stimulation. The increase in osmolality was much smaller after atropine, a small peak remaining at the 50–60th s after the beginning of stimulation. The latter effect was blocked by propranolol (0.5 mg/kg). Atropine similarly almost completely abolished the vasodilator effect and the increase in osmolality produced by lumbar sympathetic stimulation and acetylcholine. The increase in osmolality was caused by a rise in the contents of Na+ (7.4%), lactate (8.2%) and K+ (13.2%); Ca2+, inorganic phosphate and total protein concentrations remained unchanged. Our data indicate that acetylcholine released by sympathetic endings activates muscle fibre metabolism via the muscarin-receptors. The increase in tissue osmolality resulting from activation of metabolism causes, at least partly, the vasodilator effect.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2013
    Keywords: Acetylcholine ; Cholinergic vasodilatation ; cGMP ; cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Phosphorylase activity and content of cyclic GMP and AMP were investigated in the gastrocnemius muscle of the cat during the development of cholinergic vasodilation evoked by stimulation of the hypothalamus. Samples of muscle tissue were taken during an early stage of the vascular effect. One of the hindlimbs was denervated and served as control. With the development of the dilator response the conductance in the bed of the femoral artery increased by 143±12%, phosphorylase “a” activity reached 76.1±2.1% of the total phosphorylase activity as compared with 49.2±1.9% in the control, the content of cGMP increased approximately 2-fold. The content of cAMP remained unchanged. All these effects — the increase in blood flow, phosphorylase activation and the increase in cGMP content — were abolished by atropine. It is suggested that acetylcholine, released by sympathetic endings during hypothalamic stimulation, has the effect of increasing the level of intracellular cGMP and that the vasodilation is secondary to the metabolic changes.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] According to Edwards et al.10, the intestinal smooth muscle of animals with a hypertrophied sympathetic system contains seven times as much noradrenaline as normal. We obtained NGF from a homogenate of salivary glands by the method of Cohen11,12 and used the CM-I fraction. As well as NGF, this ...
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 35 (1979), S. 204-204 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The frequency of spontaneous activity of single preganglionic fibres in the cervical sympathetic nerve of sympathectomized and intact animals was compared, and was found to be higher in the sympathectomized group, averaging 5.9±1.4 pulses per sec, compared with 2.3±0.5 in the control group.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 33 (1977), S. 39-40 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The data obtained are evidence of the decreased resistance of sympathectomized animals to excitement caused by afferent stimuli.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Выводы При исследовании гладкой мышцы кишечника, гипериннервированной симпатическими волокнами, показано, что чувствительность ее к норадреналину ниже, чем у нормальной. Болеенизкая чувствительнссть наблюдается и на фоне дейстбия кокаина. Предполагается, что при избытке симпатическиш окончаний в ткани чувствительность гладкомышечныш клеток к медиаитору понижена.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2013
    Keywords: Mental arithmetic ; Skeletal muscle blood flow ; Evoked contraction of skeletal muscle ; Muscle metabolism ; McArdle's syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mechanism of the increase of muscle performance and of vasodilation during emotional stress was studied. The “emotional” increment of voluntary performance does not depend on the level of blood supply to the working muscles, and the effect is maintained under conditions of cessation of arterial inflow. Augmentation of muscle performance is also observed during emotional stress when isometric contraction is evoked by electrical tetanic stimulation of the nerve, when the number of muscle fibres participating in the evoked response does not increase during emotional stress. The “emotional” vasodilation is greatly reduced in patients suffering from McArdle's syndrome, in whom the normal course of glycolysis in muscles is disrupted. It is suggested that acetylcholine liberated from sympathetic fibres causes the activation of glycolysis in muscles, which in its turn induces vasodilation in resting skeletal muscles and increase of muscle performance during emotional stress.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-2013
    Keywords: Cholinergic vasodilatation ; Skeletal muscle performance ; Acetylcholine ; Atropine ; Adrenaline ; Propanolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence exerted by stimulation of the anterior hypothalamus (zone of cholinergic vasodilatation) on the performance of triceps surae during tetanic contraction has been investigated. Hypothalamic stimulation, if combined with indirect muscle stimulation, improves muscle performance, i.e. slows down the rate of decrease of contraction. The effect is abolished by atropine (0.5 mg/kg) and insensitive to propanolol (0.1 mg/kg). The cholinergic influence is only effective if hypothalamic stimulation coincides with the beginning of motor nerve stimulation. In some of our experiments stimulation of the same central structures elicited another influence on muscle performance, associated with the release of adrenaline into the blood. In this case, contrary to the cholinergic influence, the force of contraction increases only when hypothalamic stimulation does not start earlier than 100 s after the initiation of contraction (phase of slow decline of tension). The effect is insensitive to atropine (0.1 mg/kg) and abolished by propanolol (0.1 mg/kg).
    Type of Medium: Electronic Resource
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