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1.
In slowly secreting submandibular glands of dogs, a sympathetic effect on myoepithelial cells was demonstrated as an acceleration of the flow, followed by retardation, on short-lasting sympathetic stimulation, particularly after beta-adrenoceptor-blocking drugs. 相似文献
2.
R S Tuttle 《Experientia》1986,42(7):817-819
Pressor responses evoked by stimulation of the preganglionic sympathetic trunk of the feline superior cervical ganglion have been recorded in vivo from the vascular bed perfused by one external carotid and the vertebral artery. When vasoconstrictor activity is blocked and potential vasodilator activity enhanced by close, intracarotid injection of guanethidine and prostaglandin F2 alpha respectively, stimulation evokes a weak pressor response followed, on cessation of stimulation, by a prolonged vasodilation lasting for 6-8 min. The magnitude and duration of the poststimulation vasodilation was reduced significantly by atropine. Due to the prolonged nature of the vasodilation, it is unlikely that a sympathetic cholinergic vasodilation in the classical sense is involved. 相似文献
3.
Summary The influences of clonidine, tetracaine and procaine on the effects of electrical stimulation of the postganglionic sympathetic cardiac nerves have been compared in the isolated perfused rabbit heart. Much lower concentrations of clonidine than of tetracaine were necessary to antagonize the output of noradrenaline and the rise of frequency and contractility. Procaine even in the highest concentration tested did not inhibit the effects of nerve stimulation. In addition to its known central depression of sympathetic tone, clonidine exerts a specific inhibitory action on postganglionic sympathetic neurons. 相似文献
4.
B. Blum J. Israeli O. Hart M. Mihiz M. Farchi 《Cellular and molecular life sciences : CMLS》1987,43(10):1106-1109
Summary Pressor and tachycardic effects induced in the cat by stimulation of a lateral hypothalamic (LH) site, are shown to be mediated by sympathetic ganglia nicotinic receptor, and potentiated under atropine methyl nitrate sympathetic ganglia blockage. It is postulated that a sympatho-inhibitory pathway muscarinic ganglionic mechanism, co-activated by the LH stimulation, attenuates the pressor and tachycardic effects, the potentiation presumably being a manifestation of blockage of that mechanism. 相似文献
5.
Pressor and tachycardic effects induced in the cat by stimulation of a lateral hypothalamic (LH) site, are shown to be mediated by sympathetic ganglia nicotinic receptor, and potentiated under atropine methyl nitrate sympathetic ganglia blockage. It is postulated that a sympatho-inhibitory pathway muscarinic ganglionic mechanism, co-activated by the LH stimulation, attenuates the pressor and tachycardic effects, the potentiation presumably being a manifestation of blockage of that mechanism. 相似文献
6.
Electrical stimulation in lateral sites of the upper cervical spinal cord evoked vasodilatation after adrenergic blockade. Sympathetic fibres mediating sustained vasodilatation were shown to be separate from adrenergic sympathetic fibres since the adrenergic vasoconstrictor response in the paw evoked by vasomotor stimulation in the medulla was not reversed to vasodilatation after bretylium. 相似文献
7.
R. S. Tuttle 《Cellular and molecular life sciences : CMLS》1986,42(7):817-819
Summary Pressor responses evoked by stimulation of the preganglionic sympathetic trunk of the feline superior cervical ganglion have been recorded in vivo from the vascular bed perfused by one external carotid and the vertebral artery. When vasoconstrictor activity is blocked and potential vasodilator activity enhanced by close, intracarotid injection of guanethidine and prostaglandin F2 respectively, stimulation evokes a weak pressor response followed, on cessation of stimulation, by a prolonged vasodilation lasting for 6–8 min. The magnitude and duration of the poststimulation vasodilation was reduced significantly by atropine. Due to the prolonged nature of the vasodilation, it is unlikely that a sympathetic cholinergic vasodilation in the classical sense is involved. 相似文献
8.
Summary In slowly secreting submandibular glands of dogs, a sympathetic effect on myoepithelial cells was demonstrated as an acceleration of the flow, follwed by retardation, on short-lasting sympathetic stimulation, particularly after -adrenoceptor-blocking drugs.Supported by grant No. 14X-00539 from the Swedish Medical Research Council 相似文献
9.
P H Chanh I Sokan M C Azum-Gelade A P Chanh L Lareng 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(13):1081-1084
In Rabbit carotid sinus, the presence of sympathetic nerve endings capable of releasing noradrenaline has been demonstrated. The release of NA in response to sympathetic nerve stimulation was decreased by PgE2 and a precursor of Pg (arachidonic acid) but was strongly increased by an inhibitor of Pg biosynthesis (indomethacin). The experiments carried out demonstrated that freshly synthesized Pg acts in the same way as exogenous Pg and suggested that Pg could have a regulating effect on adrenergic neurotransmission in carotid sinus. The role of this regulating mechanism in the physiology of carotid sinus has been discussed. 相似文献
10.
A slow, long-lasting 'degeneration secretion' from the parotid gland was brought about in anaesthetized rats by section of the auriculo-temporal nerve 16--19 h in advance. This parasympathetic background activity greatly increased the secretion of amylase elicited by sympathetic nerve stimulation. 相似文献
11.
Transient sympathetically-mediated depressor effects were induced by stimulation of a small locus in the lateral hypothalamic peri-fornical region, medial to the fields of Forel. The ganglionic blocking agent, atropine methyl nitrate (ATMN), was used to show that muscarinic as well as non-muscarinic sympathetic ganglion receptor neurotransmission was involved. Evidence is presented that stimulation of this LH site co-activates a number of mechanisms and that depending on which of these are activated, the ganglionic blocking agent ATMN may either block, reverse or potentiate the depressor effect. 相似文献
12.
Summary The hindlimb of cat was separated from the body, the sciatic nerve remaining intact, The separated hindlimb was perfused through the femoral artery with tyrode solution. Synthetic bradykinin and kallidin injected into the femoral artery elicit vasoconstriction in the hindlimb, reflex on the systemic blood pressure, and stimulation of respiration. We assumed the cause of this reflex to be general sympathetic excitation through stimulation of chemoreceptor cells in the blood vessels of the hindlimb of the cat. 相似文献
13.
Summary Electrical stimulation in lateral sites of the upper cervical spinal cord evoked vasodilatation after adrenergic blockade. Sympathetic fibres mediating sustained vasodilatation were shown to be separate from adrenergic sympathetic fibres since the adrenergic vasoconstrictor response in the paw evoked by vasomotor stimulation in the medulla was not reversed to vasodilatation after bretylium.Supported by USPHS Grant No. HL 08570 and part of thesis work by Dr.Rolewicz. 相似文献
14.
P H Chanh I Sokan J P Basile A P Chanh M C Azum-Gelade 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(14):1125-1128
The experiments carried out showed the presence- in sympathetic nerve endings ot the carotid sinus- of alpha and beta adrenoceptors which by means of respective negative and positive feedback processes, modulated NA release induced by a sympathetic nerve stimulation. Similarly, Pgs acted by means of a negative feedback mechanism to regulated adrenergic neuro-transmission in carotid sinus but they could not be considered as the chemical mediators of either alpha or beta adrenoceptors. 相似文献
15.
The regular periodic activity patterns of mammalian cold receptors have been quantitatively studied. Analysis of the timing of either single impulses or impulse groups demonstrated that the periodic receptor process is maintained independently of impulse generation and continues to operate under conditions when afferent impulses are not initiated. These results imply that the underlying conductances must be operational at threshold potentials related to impulse generation. In addition to temperature, the periodic process is considerably sensitive to calcium, which affects mainly the probability of impulse generation during each cycle. Reduction of external calcium and application of calcium entry blockers with relative selectivity for low-threshold calcium channels are similarly effective in modulating cold receptor activity. The data imply the existence of a low-threshold calcium conductance at the sensory terminal. 相似文献
16.
Summary The regular periodic activity patterns of mammalian cold receptors have been quantitatively studied. Analysis of the timing of either single impulses or impulse groups demonstrated that the periodic receptor process is maintained independently of impulse generation and continues to operate under conditions when afferent impulses are not initiated. These results imply that the underlying conductances must be operational at threshold potentials related to impulse generation. In addition to temperature, the periodic process is considerably sensitive to calcium, which affects mainly the probability of impulse generation during each cycle. Reduction of external calcium and application of calcium entry blockers with relative selectivity for low-threshold calcium channels are similarly effective in modulating cold receptor activity. The data imply the existence of a low-threshold calcium conductance at the sensory terminal. 相似文献
17.
B. I. Tkachenko P. K. Pozdnjakov N. Ja. Medvedeva 《Cellular and molecular life sciences : CMLS》1976,32(9):1168-1170
Summary There is a correlation between character and magnitude of capacitance vessel responses and venous blood oxygen saturation under electrical stimulation of sympathetic fibres in the spleen and small intestine. 相似文献
18.
B. Blum J. Israeli O. Hart M. Farchi 《Cellular and molecular life sciences : CMLS》1989,45(10):991-996
Summary Transient sympathetically-mediated depressor effects were induced by stimulation of a small locus in the lateral hypothalamic peri-fornical region, medial to the fields of Forel. The ganglionic blocking agent, atropine methyl nitrate (ATMN), was used to show that muscarinic as well as non-muscarinic sympathetic ganglion receptor neurotransmission was involved. Evidence is presented that stimulation of this LH site co-activates a number of mechanisms and that depending on which of these are activated, the ganglionic blocking agent ATMN may either block, reverse or potentiate the depressor effect. 相似文献
19.
I. Palik M. Zs. Koltai M. Wagner I. Kolonics G. Pogátsa 《Cellular and molecular life sciences : CMLS》1982,38(8):934-935
Summary The conductivity of the coronary arterial bed increased in healthy and decreased in alloxan-diabetic dogs in response to intracoronary administration of norepinephrine or sympathetic stimulation. This suggests a modification of adrenergic receptors sensitivity in diabetes. 相似文献
20.
Effects of sympathetic stimulation on ventricular refractory periods in cats with acute coronary artery ligation 总被引:1,自引:0,他引:1
Ventricular refractory periods shorten in the ischemic area following acute coronary artery ligation. Subsequent bilateral sympathetic nerve stimulation reduces disparity in refractory periods across normal, border (peri-ischemic) and ischemic areas. 相似文献