Isolated Papillary Muscle Research Articles

Effect of parathyroid hormone on the isolated papillary muscle of the rat heart.

It has been well accepted that the bone and the kidney are the principal organs of parathyroid hormone (PTH) action. Several lines of evidence obtained during the last decade suggest that PTH directly acts on organs other than the bone and kidney; these include the brain, liver and blood cells (1–5).

Deactivation of contraction by quick releases in the isolated papillary muscle of the cat. Effects of lever damping, caffeine, and tetanization.

In the isolated cat papillary muscle, the time course of activation during isometric contraction was measured using instantaneous velocity of shortening after quick releases at constant contractile element length and controlled load. Activation rose and declined ahead of isometric force. This course of activation could be altered by the mode of the quick release. Undamped quick releases increasingly deactivated contraction with time. Deactivation was reduced by damping the rapid movement of the lever after the release and by increasing the afterloads to which the releases were made, thus lessening the extent of the releases. The curves of activation obtained from releases to different afterloads converged after the first half of the rising phase of the twitch. Deactivation from quick releases was eliminated by tetanizing the muscle. Hence, the instantaneous relation of force and velocity of shortening was not unique relative to time except when the muscle was tetanized. Deactivation was also reduced by lowering the temperature, by adding 10 m M caffeine, or by increasing the Ca 2+ concentration in the bathing medium in the presence of 10 m M caffeine. These results suggest that quick releases deactivate contraction by uncoupling crossbridges which can be reformed if the Ca 2+ available to activate contractile sites is not sequestered elsewhere.

Action of Ultrasonicated Epinephrine: Potentiation of Isometric Contraction in Isolated Papillary Muscle from Dog Quiescent Heart

Epinephrine solutions were exposed to ultrasonic frequencies or to oxidation by passing oxygen through the solution until a pink color was formed. The effects of these epinephrine solutions were investigated on the physiological functions of heart papillary muscles and their contractile element, i.e., actomyosin. When added to the bathing medium containing papillary muscle from beating rat hearts, the modified epinephrine produced a gradual increase in the maximum response of the muscle to electrical stimulation. If the incubating medium contained papillary muscle from quiescent dog heart, the muscle did not respond to electrical stimulation alone or in the presence of epinephrine. However, when added to the bathing medium, the sonified or the oxidized epinephrine caused initiation and potentiation of isometric contractions in response to electrical stimulation. The effects of the altered epinephrines on papillary muscles from both types of hearts were concentration and time dependent. When added with either the sonified or the oxidized epinephrine, a “serum protein” isolated from human serum intensified and stabilized the effects of both forms of epinephrine on the papillary muscle from rat or dog quiescent heart. When added to a standard actomyosin solution in imidazole–potassium chloride–ethyleneglycol tetraacetate salt buffer at pH 7.0, adenosine triphosphate caused precipitation of the contractile protein, which was assessed by the increase in absorbance and was measured spectrophotometrically at 660nm. When the incubation mixture contained increments of the sonified or the oxidized epinephrine, the precipitating effect of adenosine triphosphate was not changed. But, if added with either modified epinephrine, the serum protein caused two- or fivefold increases in the precipitation of the contractile elements from solutions incubated in the presence of the oxidized or sonified epinephrine, respectively.

Role of magnesium in effects of epinephrine on heart contraction and metabolism

ARTICLESRole of magnesium in effects of epinephrine on heart contraction and metabolismBM Paddle, and N HaugaardBM Paddle, and N HaugaardPublished Online:01 Oct 1971https://doi.org/10.1152/ajplegacy.1971.221.4.1178MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMagnesium deficiency and cardiogenic shock after cardiopulmonary bypassThe Annals of Thoracic Surgery, Vol. 64, No. 2Myocardial magnesium transport: effect of gramicidin S and epinephrineLife Sciences, Vol. 55, No. 23L’utilisation du sulfate de magnésium pendant la chirurgie du phéochromocytome: à propos de deux casCanadian Journal of Anaesthesia, Vol. 40, No. 6Role of Calcium in Heart Function and MetabolismInteractions between Mg and Blood PressurePurification and characterization of a Ca2+-dependent ATPase from rat heart sarcolemma.Journal of Biological Chemistry, Vol. 257, No. 23Circulatory shock associated with magnesium depletionIntensive Care Medicine, Vol. 8, No. 3PYRUVATE DEHYDROGENASE ACTIVATION IN RAT BRAIN CORTICAL SLICES BY ELEVATED CONCENTRATIONS OF EXTERNAL POTASSIUM IONSJournal of Neurochemistry, Vol. 28, No. 5Opposing actions of calcium and magnesium ions on the metabolic effects of epinephrine in rat heartBiochemical Pharmacology, Vol. 25, No. 17Myocardial high energy phosphates as influenced by catecholamines and pressure loadPfl�gers Archiv European Journal of Physiology, Vol. 349, No. 4Action of Ultrasonicated Epinephrine: Potentiation of Isometric Contraction in Isolated Papillary Muscle from Dog Quiescent HeartJournal of Pharmaceutical Sciences, Vol. 62, No. 5Action of a serum protein on muscular contractionPfl�gers Archiv European Journal of Physiology, Vol. 338, No. 2The Effect of Epinephrine, Glucagon, and the Nutritional State on the Oxidation of Branched Chain Amino Acids and Pyruvate by Isolated Hearts and Diaphragms of the RatJournal of Biological Chemistry, Vol. 248, No. 2 More from this issue > Volume 221Issue 4October 1971Pages 1178-1184 Copyright & PermissionsCopyright © 1971 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1971.221.4.1178PubMed5165101History Published online 1 October 1971 Published in print 1 October 1971 Metrics

Mechanical properties of relaxing frog skeletal muscle.

ARTICLESMechanical properties of relaxing frog skeletal muscleAS BahlerAS BahlerPublished Online:01 Jun 1971https://doi.org/10.1152/ajplegacy.1971.220.6.1983MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByPhysiology of left ventricular diastolic functionBaillière's Clinical Anaesthesiology, Vol. 11, No. 4Muscle relaxation and sarcoplasmic reticulum function in different muscle types23 June 2005The Relation Between Contraction Dynamics and the Intracellular Calcium Transient in Mammalian Cardiac MuscleActive Shortening Retards the Decline of the Intracellular Calcium Transient in Mammalian Heart MuscleScience, Vol. 221, No. 4606Factors modulating the sensitivity of the relaxation to the loading conditions in rat cardiac musclePfl�gers Archiv European Journal of Physiology, Vol. 394, No. 4Muscle, the Motor1 January 2011Isometric relaxation in rat myocardium: Load dependence and influence of caffeineExperientia, Vol. 35, No. 12Deactivation of Contraction by Quick Releases in the Isolated Papillary Muscle of the CatCirculation Research, Vol. 34, No. 2 More from this issue > Volume 220Issue 6June 1971Pages 1983-1990 Copyright & PermissionsCopyright © 1971 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1971.220.6.1983PubMed5087850History Published online 1 June 1971 Published in print 1 June 1971 Metrics

Effect of serum on fatigue of normal and dystrophic muscles

ARTICLESEffect of serum on fatigue of normal and dystrophic musclesLP Gabel, E Vance, and C TruaxLP Gabel, E Vance, and C TruaxPublished Online:01 May 1970https://doi.org/10.1152/ajplegacy.1970.218.5.1495MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByRecovery of isolated ‘Na-Rich’ rat muscles in the presence of serumLife Sciences, Vol. 13, No. 7Effect of growth hormone and thyroxine on the contractile properties of dystrophic muscleExperientia, Vol. 29, No. 7Action of Ultrasonicated Epinephrine: Potentiation of Isometric Contraction in Isolated Papillary Muscle from Dog Quiescent HeartJournal of Pharmaceutical Sciences, Vol. 62, No. 5Action of a serum protein on muscular contractionPfl�gers Archiv European Journal of Physiology, Vol. 338, No. 2 More from this issue > Volume 218Issue 5May 1970Pages 1495-1499 Copyright & PermissionsCopyright © 1970 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1970.218.5.1495PubMed5438279History Published online 1 May 1970 Published in print 1 May 1970 Metrics

A simple technique for production of chronic complete heart block in dogs.

A simple technique for production of chronic complete heart block in dogs.

ELECTROGRAM OF ISOLATED PAPILLARY MUSCLE OF THE CAT HEART

ArticleELECTROGRAM OF ISOLATED PAPILLARY MUSCLE OF THE CAT HEARTSolomon Garb, and Maynard B. ChenowethSolomon GarbFrom the Department of Pharmacology, Cornell University Medical College, and Maynard B. ChenowethFrom the Department of Pharmacology, Cornell University Medical CollegePublished Online:01 Jan 1949https://doi.org/10.1152/ajplegacy.1949.156.1.27MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation More from this issue > Volume 156Issue 1January 1949Pages 27-34 Copyright & PermissionsCopyright © 1949 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1949.156.1.27PubMed18117571History Received 10 September 1948 Published online 1 January 1949 Published in print 1 January 1949 Metrics