Resistance to blood flow in leg muscles of dog during tetanic isometric contraction

Gray, Stanton B.; Nc, Staub

doi:10.1152/ajplegacy.1967.213.3.677

Cited by 30 publications

(17 citation statements)

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“…It is known that contractions of this intensity severely restrict muscle blood flow due to nipping and compression of vessels between facial planes and contracting muscle fibers. 24 ' 25 In fact, we did not observe a significant increase in muscle blood flow even in the untreated condition. Due to these restrictions, we believe that under our experimental conditions indomethacin did not significantly alter muscle blood flow.…”

Section: Discussioncontrasting

confidence: 51%

Prostaglandins contribute to cardiovascular reflexes evoked by static muscular contraction.

Stebbins¹,

Maruoka

Longhurst

1986

Circulation Research

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The purpose of this study was to determine the contribution of prostaglandins to the reflex cardiovascular responses induced by static contraction of the hind limb in cats, i.e., the exercise reflex. To accomplish this, the cardiovascular responses to hind limb contraction induced by electrical stimulation of spinal cord ventral roots L^ and S, were compared before and after inhibition of prostaglandin synthesis (indomethacin, 2-6 mg/kg i.v., n = 5, or sodium meclofenamate, 2-6 mg/kg i.v., n = 5) or after injection of prostaglandin E 2 into the hind limb arterial blood supply. Treatment with indomethacin attenuated the contraction-induced increase in mean arterial pressure and left ventricular dP/dt by 76% and 86%, respectively. Heart rate and average developed triceps surae muscle tension were unchanged. After administering sodium meclofenamate, the reflex response was attenuated to a similar degree. In the indomethacin-treated animals, injection of exogenous prostaglandin E 2 (PGE 2 ) partially restored the pressor and myocardial contractile responses. In 6 animals, treatment with exogenous PGE 2 without prior inhibition of prostaglandin synthesis did not significantly augment the contraction-induced cardiovascular response. Using the radioactive microsphere technique, we measured skeletal muscle blood flow during contraction before and after treatment with indomethacin (n = 6) to determine if an indomethacin-induced alteration in blood flow could account for the attenuated contraction-induced cardiovascular response. Blood flow during static muscle contraction was not significantly altered by indomethacin. We conclude that prostaglandins contribute to the exercise reflex through an action on afferent nerve endings rather than through a regional vascular effect. (Circulation Research 1986;59:645-654)

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Section: Discussioncontrasting

confidence: 51%

Prostaglandins contribute to cardiovascular reflexes evoked by static muscular contraction.

Stebbins¹,

Maruoka

Longhurst

1986

Circulation Research

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“…With stronger contractions, however, the blood pres sure, heart rate, and cardiac output invariably continue to rise until muscular fatigue prohibits continued contraction. In keeping with earlier suppositions, it is now clear that stronger contractions can cause mechanical interference to blood flow to the muscle (8,19,20), and the resultant ischemia presumably contributes to the rapid development of fatigue. In general, the rate at which hemodynamic factors change during exertion and the final extent of their change are directly related to the strength of muscle contraction and inversely related to the time required to produce fatigue.…”

Section: Cardiov Ascular Effects Of Static Exercisesupporting

confidence: 55%

Static (Isometric) Exercise and the Heart: Physiological and Clinical Considerations

Mitchell¹,

Wildenthal²

1974

Annu. Rev. Med.

164

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“…These earlier human studies were done in limbs in which circulation was occluded 3 min before exercise. Animal studies used tetanic nerve stimulation during which blood (and oxygen) supply to muscle is virtually blocked (38). These studies were done in conditions where the supply of energy must rely on glycolytic rather than aerobic metabolism.…”

Section: P Nmrmentioning

confidence: 99%

Effects of thyroid hormones on skeletal muscle bioenergetics. In vivo phosphorus-31 magnetic resonance spectroscopy study of humans and rats.

et al. 1988

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The pathophysiology of the myopathy in dysthyroid states is poorly understood. We therefore tested the effects of thyroid hormones on muscle bioenergetics in humans and rats, using in vivo 31P NMR. Two hypothyroid patients had: low phosphocreatine to inorganic phosphate ratio (PCr/Pi) at rest, increased PCr depletion during exercise and delayed postexercise recovery of PCr/Pi. Eight thyroidectomized rats did not show abnormalities at rest, but muscle work induced by nerve stimulation resulted in a significantly (P < 0.0001) lower PCr/ Pi (3545% of control) at each of the three stimulation frequencies tested (0.25, 0.5, and 1.0 Hz). Recovery rate was markedly slowed to one-third of normal values. Thyroxine therapy reversed these abnormalities in both human and rat muscle. Five patients and six rats with hyperthyroidism did not differ from normal controls during rest and exercise but had an unusually rapid recovery after exercise. The bioenergetic abnormalities in hypothyroid muscle suggest the existence of a hormone-dependent, reversible mitochondrial impairment in this disorder. The exercise intolerance and fatigue experienced in hypothyroid muscle may be due to such a bioenergetic impairment. The changes in energy metabolism in hyperthyroid muscle probably do not cause the muscular disease in this disorder.

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Resistance to blood flow in leg muscles of dog during tetanic isometric contraction

Cited by 30 publications

References 0 publications

Prostaglandins contribute to cardiovascular reflexes evoked by static muscular contraction.

Prostaglandins contribute to cardiovascular reflexes evoked by static muscular contraction.

Static (Isometric) Exercise and the Heart: Physiological and Clinical Considerations

Effects of thyroid hormones on skeletal muscle bioenergetics. In vivo phosphorus-31 magnetic resonance spectroscopy study of humans and rats.

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