Myocardial Contraction

Publication Title: 
Journal of Ethnopharmacology

The effects of Abana, an Ayurvedic remedy, administered orally to rabbits was studied for its effects on isolated atria and intestine. Administration of Abana for 3 days increased the basal amplitude and reduced the responses of atria to isoprenaline and norepinephrine. Combined treatment with Abana and isoprenaline reduced this effect. It is possible that Abana treatment for 3 days has an action similar to that of chronic administration of isoprenaline (down regulation of beta receptors). A similar down regulation of beta receptors of smooth muscle of rabbit intestine also seems to occur.

Author(s): 
Pasnani, J. S.
Hemavathi, K. G.
Gulati, O. D.
Rajani, A. P.
Publication Title: 
Journal of Ethnopharmacology

Oxidative damage to crucial biomolecules due to excess generation of reactive oxygen species has been implicated as a major cause of organ damage and hence compounds capable of negating such damage have potential benefits. Using hydrogen peroxide (H2O2) as a model pro-oxidant to induce oxidative stress, we have examined the ability of natural food supplement Maharishi Amrit Kalash (MAK-4) to decrease oxidative damage in potassium-arrested isolated rat hearts.

Author(s): 
Cullen, W. J.
Dulchavsky, S. A.
Devasagayam, T. P.
Venkataraman, B. V.
Dutta, S.
Publication Title: 
Current Pharmaceutical Biotechnology

The stem bark of Terminalia arjuna (Roxb.) is used by the Ayurvedic physicians in India for the treatment of various cardiovascular diseases, collectively referred to as hritroga. It has been extensively studied in animal models to demonstrate cardioprotective properties, ranging from positive inotropic- , hypolipdemic-, coronary vasodilatory- and antioxidant effects to induction of stress protein in heart. Various bioactive compounds, like triterpinoids, tannins, flavonoids and minerals have been isolated from the stem bark.

Author(s): 
Maulik, S. K.
Katiyar, C. K.
Publication Title: 
American Journal of Physiology. Heart and Circulatory Physiology

Glucose-mediated oxidative stress and the upregulation of cyclooxygenase (COX)-2 pathway activity have been implicated in the pathogenesis of several vascular complications of diabetes including diabetic neuropathy. However, in nondiabetic subjects, the cardiovascular safety of selective COX-2 inhibition is controversial. The aim of this study was to explore the links between hyperglycemia, oxidative stress, activation of the COX-2 pathway, cardiac sympathetic integrity, and the development of left ventricular (LV) dysfunction in experimental diabetes.

Author(s): 
Kellogg, Aaron P.
Converso, Kimber
Wiggin, Tim
Stevens, Martin
Pop-Busui, Rodica
Publication Title: 
Cardiovascular Pathology: The Official Journal of the Society for Cardiovascular Pathology

BACKGROUND: Introduction of the yellow obese gene (A(y)) into mice (KKAy) results in obesity and diabetes by 5 weeks of age. METHODS: Using this model of type 2 diabetes, we evaluated male and female 6- to 8-month-old wild-type (WT, n=10) and KKAy (n=22) mice subjected to myocardial infarction (MI) and sacrificed at day (d) 7. RESULTS: Despite similar infarct sizes (50% ± 4% for WT and 49% ± 2% for KKAy, P=not significant), the 7d post-MI survival was 70% (n=7/10) in WT mice and 45% (n=10/22) in KKAy mice (P<.05).

Author(s): 
Heaberlin, James R.
Ma, Yonggang
Zhang, Jianhua
Ahuja, Seema S.
Lindsey, Merry L.
Halade, Ganesh V.
Publication Title: 
Clinical Cardiology

There has been no report regarding therapy of extracorporeal life support (ECLS) that showed stunned myocardium echocardiographically and electrocardiographically in patients with acute myocardial infarction. ECLS was performed in eight patients with cardiogenic shock or arrest unresponsive to catecholamines and intra-aortic balloon pumping following myocardial infarction; these patients required prolonged external cardiac massage. After the initiation of ECLS, both blood pressure and metabolic acidosis improved in all patients.

Author(s): 
Kurose, M.
Okamoto, K.
Sato, T.
Kukita, I.
Taki, K.
Goto, H.
Publication Title: 
Cardiovascular Engineering (Dordrecht, Netherlands)

Our institution is in development of a low frequency, non-invasive Diastolic Timed Vibrator (DTV) for use in emergency treatment of ST Elevation Myocardial Infarction (STEMI). It is preferable to avoid vibration emissions during the IsoVolumetric Contraction Period (IVCP) and at least the majority of mechanical systole thereafter, as systolic vibration may cause a negative inotropic effect in the ischemic heart.

Author(s): 
Gill, Harjit
Hoffmann, Andrew
Publication Title: 
Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas / Sociedade Brasileira De Biofísica ... [et Al.]

Many pharmacological effects have been ascribed to extracts of Psidium guajava L. (guava) leaves. However, in spite of its widespread use in Brazilian folk medicine and a reasonable number of scientific reports about it, we could not find any study dealing with its action on the mammalian myocardium. In the present study, by measuring isometric force, we observed that the crude extract of P. guajava (water-alcohol extract obtained by macerating dry leaves) depresses the guinea pig atrial contractility in a concentration-dependent fashion (N = 8 hearts, 15 trials).

Author(s): 
Conde Garcia, E. A.
Nascimento, V. T.
Santiago Santos, A. B.
Publication Title: 
Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas / Sociedade Brasileira De Biofísica ... [et Al.]

The objective of the present investigation was to determine the contractile effect of crude and acetone leaf extracts of Citrus sinensis (L.) Osb. on mammalian myocardium. Crude leaf extracts have been used in folk medicine to treat neurological disorders. Some flavonoids isolated from this plant presented a positive inotropic effect on myocardium. This motivated us to test the extracts on the atria of guinea pigs of both sexes (300-500 g) and surprisingly we observed inotropic depression instead of an increase in force.

Author(s): 
Oliveira, E. D.
Leite, T. S.
Silva, B. A.
Conde-Garcia, E. A.
Publication Title: 
Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas / Sociedade Brasileira De Biofísica ... [et Al.]

It has been reported that star fruit can lead to a fatal outcome in uremic patients. The intoxication syndrome consists of hiccups, mental confusion, dizziness, and vomiting. On the other hand, folk medicine uses teas and infusions of carambola leaves to treat headache, vomiting, cough, insomnia, and diabetes. This motivated us to determine if Averrhoa carambola can act on the contractility and automaticity of the guinea pig heart. We measured the atrial isometric force in stimulated left atria and determined the chronotropic changes in spontaneously beating right atria.

Author(s): 
Vasconcelos, C. M. L.
Araújo, M. S.
Silva, B. A.
Conde-Garcia, E. A.

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