Potassium-induced cardiovascular and ventilatory reflexes from the dog hindlimb

Wildenthal, K.; Mierzwiak, DS; Ns, Skinner; Mitchell, J. H.

doi:10.1152/ajplegacy.1968.215.3.542

Cited by 85 publications

(27 citation statements)

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“…Increased tension acting via unidentified receptors in the muscles or through irradiation from the motor cortex (20) may stimulate the autonomic centers causing a relatively higher sympathetic outflow which in turn will increase heart rate and blood pressure. Mitchell and coworkers (17,22) found a distinct increase in cardiac output, heart rate, and arterial pressure in dogs when stimulating the afferent nerve from the quadriceps muscle (the responses in cardiac output and heart rate were abolished by padrenergic blockade). Iaria and coworkers (12) have also postulated the existence of some 'ergoreceptors' responding to tension in the muscles.…”

Section: Discussionmentioning

confidence: 99%

Cardiac Output during Positive and Negative Work

Thomson¹

1971

Scandinavian Journal of Clinical and Laboratory Investigation

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Thomson, D. A. Cardiac Output during Positive and Negative Work. Scand.1. din. Lab. Invest, 27, 193-200, 1971.Cardiac output was studied in two series of experiments during positive (concentric) and negative (eccentric) bicycle ergometer work. Cardiac output (COz-rebreathing and dye dilution methods) was higher during negative work compared to positive work at the same oxygen consumption, provided this was over 1 litre per min. H e a r t rate was increased to the same extent as cardiac output. Mean arterial blood pressure was also higher, and blood lactate concentration slightly lower for negative work compared to positive work. An increased local temperature and/or a higher muscular tension may be factors which besides oxygen demand influence heart rate and cardiac output during negative work. SwedenScand J Clin Lab Invest Downloaded from informahealthcare.com by University of Queensland on 02/03/15 For personal use only. Scand J Clin Lab Invest Downloaded from informahealthcare.com by University of Queensland on 02/03/15 For personal use only. (Lond.) 120, 319, 1952. 3. Asmussen, E. Positive and negative work. Acta physiol. scand. 28, 364, 1952. 4. Asmussen, E. & Nielsen, M. Physiological dead Scand J Clin Lab Invest Downloaded from informahealthcare.com by University of Queensland on 02/03/15 For personal use only.

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Section: Discussionmentioning

confidence: 99%

Cardiac Output during Positive and Negative Work

Thomson¹

1971

Scandinavian Journal of Clinical and Laboratory Investigation

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“…This literature has been reviewed in detail by others, but some discussion is warranted due to the robust nature in which the metaboreflex stimulates muscle SNA. Several of the metabolites produced by muscular work that have been targeted as candidates for the activation of the muscle metaboreflex during exercise in humans include, but are not limited to lactic acid, potassium, adenosine, arachidonic acid, diprotonated phosphate, prostaglandins, and hydrogen ion (81,91,122,274,311,331,350,375). However, equivocal results have been reported for most of these candidates with studies supporting and refuting the involvement of each substance to some degree.…”

Section: Skeletal Muscle Metaboreflex During Steady-state Exercisementioning

confidence: 99%

Autonomic Adjustments to Exercise in Humans

Fisher

Young

Fadel

2015

Comprehensive Physiology

232

253

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Autonomic nervous system adjustments to the heart and blood vessels are necessary for mediating the cardiovascular responses required to meet the metabolic demands of working skeletal muscle during exercise. These demands are met by precise exercise intensity-dependent alterations in sympathetic and parasympathetic nerve activity. The purpose of this review is to examine the contributions of the sympathetic and parasympathetic nervous systems in mediating specific cardiovascular and hemodynamic responses to exercise. These changes in autonomic outflow are regulated by several neural mechanisms working in concert, including central command (a feed forward mechanism originating from higher brain centers), the exercise pressor reflex (a feed-back mechanism originating from skeletal muscle), the arterial baroreflex (a negative feed-back mechanism originating from the carotid sinus and aortic arch), and cardiopulmonary baroreceptors (a feed-back mechanism from stretch receptors located in the heart and lungs). In addition, arterial chemoreceptors and phrenic afferents from respiratory muscles (i.e., respiratory metaboreflex) are also capable of modulating the autonomic responses to exercise. Our goal is to provide a detailed review of the parasympathetic and sympathetic changes that occur with exercise distinguishing between the onset of exercise and steady-state conditions, when appropriate. In addition, studies demonstrating the contributions of each of the aforementioned neural mechanisms to the autonomic changes and ensuing cardiac and/or vascular responses will be covered.

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“…All other branches of the popliteal artery were carefully tied to prevent minor leakage, an essential procedure (16,18). Sometimes ligation around the femur was necessary to occlude as much blood as possible, except that flow through the femoral vessels (19 (iii) Muscle contraction. After laminectomy the ventral root of the 6th or the 7th lumbar segment was sectioned, separated from other roots, and placed on a bipolar stimulating electrode in the mineral oil pool.…”

Section: Introductionmentioning

confidence: 99%

Neuronal activity of the cat supraoptic nucleus is influenced by muscle small-diameter afferent (groups III and IV) receptors.

Kannan

Yamashita

Koizumi

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

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In anesthetized cats, responses of single neurosecretory neurons of the supraoptic nucleus to activation of muscle receptors were investigated. Electrical stimulation (1-3 pulses at 200 Hz) of group m and IV pure muscle afferents (gastrocnemius nerve) evoked excitation of >50% of supraoptic nucleus neurons (n = 50), whereas stimulation of group Ia or lb fibers was ineffective. Baroreceptor stimulation inhibited 95% of these supraoptic nucleus neurons that responded to activation of muscle afferents. Excitation of receptors in the gastrocnemius muscle by intra-arterial injection of chemi (NaCl, KCI, and bradykinin) increased firing rates of most (84%, 74%, and 80%, respectively) neurosecretary neurons. The magnitude of the excitatory response was dose dependent-bradykinin being the most effective. The response disappeared after muscle denervation. When the gastrocnemius muscle alone was contracted phasically by ventral root stimulation, discharges of the supraoptic nucleus neurons increased, whereas quick stretch of the muscle had no effect. We conclude that activation of muscle receptors by chemical or mechanical stimulus can directly excite neurosecretory neurons in the supraoptic nucleus and that afferent impulses are carried by polymodal fibers of small diameter but not by the largest afferents (group I) from the muscle. The results may relate to increased concentrations of plasma vasopressin during exercise.Physical exercise is accompanied by antidiuresis and increased plasma level of vasopressin (1-7) as well as by respiratory and cardiovascular changes (8-12). It has been suggested that these autonomic responses do not result from secondary changes induced by increases in blood volume, core temperature, or metabolic rate during exercise but result, instead, from direct excitatory neural input from polymodal receptors in the muscle to the autonomic centers (10, 11). We showed previously that the neurosecretory neurons in the supraoptic nucleus (SON) ofthe hypothalamus were affected by excitation of peripheral somatic as well as visceral afferents (13). Thus, the increased level of plasma vasopressin could also be due to activation of polymodal receptors in striated muscle.The present investigation was done for two purposes: (i) to study characteristics of afferent fibers from the muscle that excite neurosecretory neurons in the SON and (ii) (Nembutal, 35 mg/kg). Supplemental doses of the same anesthetic agents or sodium thiopental (Pentothal, 2-5 mg/kg) were given i.v. whenever necessary. No muscle relaxant was used. A trachea cannula was inserted, and the femoral artery and vein were cannulated for blood pressure recording and fluid or drug administration. Pneumothorax and artificial ventilation was used whenever necessary to minimize movement of brain tissues. The rectal or esophageal temperature was maintained between 37-38TC by a heating pad and an overhead lamp. The animal was placed in a stereotaxic head holder and hemispherectomy was done by the method described (15). The exposed surface...

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Potassium-induced cardiovascular and ventilatory reflexes from the dog hindlimb

Cited by 85 publications

References 0 publications

Cardiac Output during Positive and Negative Work

Cardiac Output during Positive and Negative Work

Autonomic Adjustments to Exercise in Humans

Neuronal activity of the cat supraoptic nucleus is influenced by muscle small-diameter afferent (groups III and IV) receptors.

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