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Results for “heart ventricles”

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At least 19 recordsLinked to original sources
PubMed1977

[Relationship between the myocardial mass and the volume of human heart ventricles in hypertrophy].

The weight and volume values of heart ventricles from patients dying of cardio-vascular and some other diseases were studied. Measuring of sarcomeres in freely fixed and controlled pressure-fixed hearts showed that with the former method of fixation heart ventricles were contracted and the volume of their cavity approached the tidal volume. In freely fixed and "fresh" hearts removed at autopsies within 2-27 hours after death, concentric and excentric hypertrophy of ventricles may be characterized by numeric values of the relative mass: the ratio of ventricle mass to volume of its cavity, and in the left ventricle--by the relative diameter of the cavity: the ratio of the cavity diameter in cross-section to the thickness of the ventricle wall.

Autopsy↗
PubMed1977

[Intracardiac nervous regulation of the systolic and diastolic activity of isolated heart ventricle].

In isolated hearts of cats and frogs, sistolic and diastolic pressure in the ventricle, volume speed, speed of contraction and relaxation, and indexes of contractability and elasticity, were estimated during stretching of the venous receptacle. The data showed that the stretching increased both the sistolic and diastolic activities of the ventricle. Shunting off of the intracardial nervous apparatus prevented these interrelationships. The increase in the ventricle sistolic and diastolic activities due to stimulation of mechanoreceptors of the heart venous receptacles can be regarded as the display of a regulatory activity of intracardial nervous system related to changes of the blood volume coming to the venous receptacles.

Animals↗
PubMed1979

Specific labelling of postsynaptic alpha 1 adrenoceptors in rat heart ventricle by 3H-WB 4101.

The alpha-adrenoceptor ligand, 3H-WB 4101 binds to a single population of independent sites in the rat heart ventricle. These sites are not affected by chemical sympathectomy with 6-hydroxydopamine and thus appear to be located postsynaptically. The relative order of potencies for displacement of 3H-WB 4101 binding:prazosin greater than phentolamine greater than yohimbine, is characteristic of that of the alpha 1 type of adrenoceptors. In heart ventricle 3H WB-4101 thus seems to label specifically postsynaptically located alpha 1-adrenoceptors. The significance of the specificity of this ligand is discussed with relevance to its use in the central nervous system.

Adrenergic alpha-Antagonists↗
PubMed1978

Hormone action at the membrane level. VII. Stimulation of dihydroalprenolol binding to beta-adrenergic receptors in isolated rat heart ventricle slices by triiodothyronine and thyroxine.

Thyroxine (T4) and triiodothyronine (T3) increase the number of beta-adrenergic receptors in heart ventricle slices. A short term effect reaches a maximum by 1.5-2 h and requires added amino acids for consistent results. The apparent Km for the L-T3 effect is 15 pM. This effect, measured by an increase in stereospecific binding of (-)-[3H]dihydroalprenolol is not inhibited by cycloheximide or puromycin and is produced more effectively by L-T3 than D-T3. However, cycloheximide nearly completely inhibits protein synthesis in the 2-3 h incubation time. T3 also gives a small inhibition of protein synthesis during this time interval. The early effect of T3 stimulation of dihydroalprenolol binding is considered to be a post-translational event shereby T3 enhances the transport of existing beta-adrenergic receptors from the cytosol into the membrane. A long term (15 h) stimulation of dihydroalprenolol binding to ventricle membranes is also produced by L-T3. This effect is stereospecific, is inhibited by cycloheximide, and is believed to be a transcriptional-translational event leading to the synthesis of new beta-adrenergic receptors by T3.

Alprenolol↗
PubMed1979

Changing form and function in one ventricle hearts.

Postnatal changes in morphology of hearts with one functioning ventricle influence physiology, natural history and physical signs. The most important and early changes relate to the acquiring of subpulmonary or subaortic stenosis. For this to occur, the basic anatomy has to be of particular arrangement; investigators should be aware of the problems and search for gradients both at rest and on Isuprel stimulation when the anatomy is appropriately disturbed. Atrio-ventricular valve regurgitation and calcification may also develop. Many changes are predictable from study of the basic pathology and knowledge of them helps to plan management at the correct time in the living patient.

Adult↗
PubMed1977

[Fibrinolytic activity of blood flowing through the heart ventricles and major vessels of rats under normal conditions and in experimental myocardial ischemia].

Sampling blood from the jugular, superior and inferior caval veins and the pulmonary artery and the heart ventricles of intact rats revealed that the fibrinolytic activity was the lowest in the jugular vein, while it was 1.5-2 times higher in the other sections. The fibrinolysis in these animals is 1.5 times higher in the right ventricle than in the left. One day after coronary artery ligation a reverse relationship is observed: the blood in the left ventricle has a 1.5-times higher fubinolytic activity than that in the right. The difference in the activity is due to a different plaminogen activator content. Three days after the onset of myocardium ischaemia the difference in the fibrinolytic activity of the blood in both ventricles disappears. The obtained data emphasize the role of local fibrinolysis in the development of cardiac pathology.

Animals↗
PubMed1979

The effects of chemical sympathectomy with 6-hydroxydopamine on alpha-adrenoceptor and muscarinic cholinoceptor binding in rat heart ventricle.

The specific binding of 3H-dihydroergocryptine to alpha-adrenoceptors in membranes from the heart ventricle of rats chemically denervated with 6-hydroxydopamine was significantly decreased in comparison with control animals. In contrast the muscarinic cholinoceptor binding of 3H-quinuclinidyl benzilate was unchanged after chemical sympathectomy. These results are interpreted as indicating that the muscarinic receptors are principally postsynaptic but that a significant proportion of the alpha-adrenoceptors are located on noradrenergic nerve terminals.

Animals↗
PubMed1976

Cardiac myosin from pig heart ventricle. Purification and enzymatic properties.

A method is described for the preparation of high purity myosin from the left ventricle of pig heart. The purified myosin was free from nucleic acid, actin, tropomyosin, troponin, the 150,000 molecular weight protein and other contaminants. Analyses of subunits in the purified myosin were carried out on 3.5% acrylamide gel with 0.1% SDS. Of the total protein present in myosin, 11.3% was in the light chains; light chain 1 (LC1), 5.9% and light chain 2 (LC2), 5.4%. Urea gel electrophoresis of the purified myosin showed three closely spaced bands corresponding to the 20,000 dalton, the charge-modified 20,000 dalton and the phosphorylated 20,000 dalton components. The properties of the Ca2+-activated and K+-activated ATPases [EC 3.6.1.3] of the purified myosin were also studied. The Km values were 27 and 55 muM and the Vmax values were 0.263 and 0.317 mumole P1/mg/min for the Ca2+-activated and K+-activated ATPases, respectively. The pH-activity profiles and the effects of SH modification were of the skeletal myosin type except that the activities were lower.

Adenosine Triphosphatases↗
PubMed1978

[Effect of acetylcholine on the heart ventricle of the goldfish Carassius auratus, Teleosts, Cyprinidae. Modification of the response as a function of temperature].

Acetylcholine (Ach) is more efficient on the red fish heart at 14 degrees C than at 5 degrees C or 8 degrees C. It does not probably exist a cholinesterasic system and high concentrations of Ach are to be used to obtain significant variations of the heart frequency. Ach does not appear as a physiological mediator and temperature seems to be an essential factor in heart regulation and modulation of the pharmacological effects of eventual mediators. A thermal adaptation exists but the fast increase of the temperature, in the presence of Ach, results in heart blocage, whose contractions reappear spontanously during cooling. This is at the present time no valuable hypothesis could be made to explain this phenomenon.

Acetylcholine↗
PubMed1978

Contraction activity of right heart ventricle and pulmonary haemodynamics in cytotoxic cardiogenic shock.

In the course of experimental cardiogenic shock in dogs it was found that in comparison with marked disturbances of heart function and haemodynamics in the systemic circulation, the changes in the right ventricular contractility were less conspicuous. The pulmonary arterial pressure kept at a level approaching the initial one. The pulmonary vascular resistance substantially rose at the same time, especially so in the arterioles. The left heart filling pressure did not increase. The authors assume that the changes in the pulmonary vascular resistance result from direct neurohumoral control of vascular resistance, and discuss possible mechanism of this control.

Animals↗