ABSTRACT
En este reporte se expone el caso de una cachorra de raza Springer Spaniel que presentaba taquipnea, ascitis, intolerancia al ejercicio, leve cianosis y baja condición corporal. A la auscultación cardiaca se evidenció un soplo 5/6 mitral que irradiaba a ambos hemitórax. En la ecocardiografía se apreció una disminución de la función contráctil del ventrículo izquierdo, hipertrofia excéntrica del atrio y ventrículo izquierdo, e insuficiencia mitral.
This is a case of a Springer spaniel puppy which presented tachypnea, ascitis, exercise intolerance, mild cyanosis and a poor body condition. At cardiac auscultation a 5/6 mitral murmur was detected that irradiated to both hemithorax. Echocardiography revealed diminished left ventricular contractility, eccentric hypertrophy of the left atrium and ventricle and mitral insufficiency.
Este relatório descreve o caso de uma cachorra da raça Springer spaniel de baixa condição corporal que tinha taquipnéia, ascite, intolerância ao exercício, cianose leve. Na ausculta cardíaca foi mostrado um fôlego 5/ 6 mitral que irradiava ambos hemitórax. Em ecocardiografia revelou uma diminuição na função contrátil do ventrículo esquerdo, excêntrica hipertrofia do ventrículo direito e átrio esquerdo e insuficiência mitral.
Subject(s)
Animals , Dogs , Cardiomegaly , Echocardiography , Heart Atria , Myocardial ContractionABSTRACT
Se evaluó farmacológicamente los extractos de diversas variedades de Magnolia grandiflora sobre el músculo cardíaco. Se recolectó en el período de marzo a julio hojas y flores de Magnolia grandiflora nativa del Instituto Nacional de Cardiología "Ignacio Chávez", de la zona norte, poniente y oriente del Distrito Federal, de los estados de Puebla, Colima y Chiapas. Éstas se procesaron por separado y los extractos se obtuvieron por maceración con una mezcla de etanol-agua (1:3 v/v) a 4°C durante dos semanas. El análisis cualitativo se realizó por cromatografía en capa fina, columna y de líquidos de alta resolución (CLAR). El análisis funcional y molecular se efectuó por reactividad química específica y resonancia magnética protónica (RMN ¹H). La evaluación farmacológica se realizó en corazones aislados de cobayo macho. Los extractos, fracciones y compuestos se administraron en bolos seriados bajo un estudio de curvas dosis-respuesta gradual en donde se midió la presión intraventricular izquierda y la presión de perfusión coronaria, evaluando así el efecto inotrópico positivo y vasodilatador de los extractos de Magnolia grandiflora. Se identificó y aisló vulgarenol y 2-p-hidroxifenil-2-OH-etilamina, por lo que los resultados sugieren que su efecto vasodilatador e inotrópico positivo, se deben a la presencia de estas sustancias, las cuales se complementan con magnograndiólido y tiramina.
Several extracts from diverse Magnolia grandiflora varieties were pharmacological evaluated in the cardiac muscle. From March to July, flowers and leaves from Magnolia grandiflora, native from the National Institute of Cardiology "Ignacio Chávez", from north, west, and orient zones from Mexico City, and from Puebla, Colima and Chiapas states were collected. They were separately processed and the extracts were obtained by maceration with ethanol-water (1:3 v/v) at 4°C during two weeks. Qualitative analysis was accomplished with thin-layer, column and high-performance liquid chromatographies (HPLC). Functional and molecular analysis was made by specific chemical reactivity and by protonic magnetic resonance (RMN ¹H). Pharmacological evaluation was completed in isolated and perfused male guinea pigs hearts. Extracts, fractions, and compounds were administrated by serial bolus in a gradual dose-response curves study in which left intraventricular pressure and coronary perfusion pressure were recorded, evaluating by such the positive inotropic and vasodilator effects of Magnolia grandifloraextracts. Vulgarenol and 2-p-hydroxyphenyl-2-hydroxy-ethylamine were isolated and identified, and the obtained results suggest that its positive inotropic and vasodilator effects are owed to these substances, being complemented by magnograndiolide and tyramine.
Subject(s)
Animals , Guinea Pigs , Male , Heart/drug effects , Magnolia , Plant Extracts/pharmacology , Case-Control Studies , Chromatography, Gel , Coronary Vessels/drug effects , Coronary Vessels/physiology , Heart/physiology , Magnetic Resonance Spectroscopy , Myocardium/metabolism , Ventricular Function, Left/drug effects , Ventricular Function, Left/physiology , Ventricular Pressure/drug effects , Ventricular Pressure/physiologyABSTRACT
Pese a su reducido margen de seguridad, los digitálicos siguen utilizándose en el tratamiento de la insuficiencia cardiaca congestiva y la fibrilación auricular crónica. Con el descubrimiento de su estructura, se han realizado remodelaciones para disminuir su toxicidad. Investigaciones recientes reportan que la eficacia digitálica radica en la electronegatividad del anillo "D" esteroideo, generada por la lactona e hidroxilo que poseen estos compuestos. En el presente trabajo, damos cuenta de la importancia que tiene esta propiedad molecular, que aunada a la conformación estructural, dan lugar a cambios significativos en las propiedades farmacológicas como el inotropismo y el margen de seguridad. Así, evaluamos una serie de once compuestos derivados de digitoxigenina, con grupos que sustituyen sobre el anillo "D" al hidroxilo y/o la lactona, los cuales denominamos -OH, -Lac, D-01, D-02, D-03, D-07, D-14, D-15, D-20, D-21 y D-22. La electronegatividad y la energía conformacional de cada compuesto se determinaron por el método Duhamm. El estudio farmacológico se realizó en corazones aislados de cobayo con base en el modelo de Langendorff y, en corazón de perro conforme al modelo cardiopulmonar de Starling. Los resultados permiten observar que la modulación de la acción digitálica está centrada, estructuralmente, en los sustituyentes de la fracción "D". El efecto inotrópico positivo y el margen de seguridad, medido como el cociente de la dosis tóxica sobre la dosis inotrópica, están relacionados con el aumento de electronegatividad y con una disminución de las energías rotacional y translacional que definen la conformación molecular; en consecuencia, estas propiedades son imprescindibles en la eficacia digitálica.
In spite their reduced therapeutic index, digitalis-type drugs continue being used for treating diseases such as congestive heart failure and chronic atrial fibrillation. Thanks to the development of several methods, their structural determination has been feasible, so, structural modifications have been worked out to modulate their toxicity. Several reports realizes that efficacy for these digitalis-type drugs lies on the electronegativity centered on the steroidal moiety (D-ring) generated by either lactone and hydroxyl sub-stituents attached to the steroidal moiety. In this work, we report how electronegativity, and so structural conformation, does modify their pharmacological properties, e.g., inotropism and safety margin. Thus, we evaluated a series of eleven drugs derived from digitoxigenin, named -OH, -Lac, D-01, D-02, D-03, D-07, D-14, D-15, D-20, D-21 and D-22, with groups that substitute both lactone and hydroxyl groups on the steroidal D-ring. Electronegativity and conformational energy were determined by Duhamm's method. The pharmacological evaluation for these drugs was accomplished in guinea pigs isolated hearts (according to the model proposed by Langendorff) and dog's isolated heart (as established by Starling's in vivo model). The results may suggest that digitalis-like action lies on the substituents attached to the D-ring. Positive inotropic effect and therapeutic index are related with increases in electronegativity as well with decreases in rotational and traslational energies; therefore, these molecular properties have such importance for the digitalis efficacy. (Arch Cardiol Mex 2003; 73:11-17).
Subject(s)
Animals , Guinea Pigs , Male , Cardiotonic Agents/pharmacology , Digitalis Glycosides/pharmacology , Heart Failure/drug therapy , Myocardial Contraction/drug effects , Stimulation, ChemicalABSTRACT
Aim To investigate the effects of propafenone on myocardium inotropism and explore it’s possible mechanism in isolated papillary muscle of guinea pig. Methods Developed tension (DT), maximum rate of contraction (+dT/dt_ max) and maxi-mum rate of relaxation (-dT/dt_ max) were measured during propafenone perfusion before and after administration of L-type calcium channel blocker, nicardipine and selective Na+/Ca 2+ exchanger inhibitor, KB-R7943. Results ①At concentration of 0.1,1,10,30 ?mol?L -1,propafenone attenuated DT from control (0.18?0.05) g to (0.14?0.03), (0.12?0.03), (0.08?0.02), (0.05?0.02) g respectively (P
ABSTRACT
AIM To investigate the positive inotropic effect of aconitine on isolated hearts from cardiac dysfunctional rats when combined with pinacidil. METHODS In our experiment Langendorff perfusion equipment was used to investigate the following cardiac indexes:LVSP(left ventricular systolic pressure), LVDP(left ventricular diastolic pressure), +d p /d t max (the maximum going up rate of left ventricular pressure) and -d p /d t max (the maximum going down rate of left ventricular pressure) from rat hearts under two conditions:① aconitine only,② aconitine plus pinacidil(an agonist of K ATP channel) to observe the positive inotropic effect of aconitine on cardiac dysfunctional rat hearts. RESULS ①Aconitine had certain positive inotropic effect on isolated hearts from cardiac dysfunctional rats; ②Combing aconitine with potassium channel activator markedly winded the doses range between the effective and toxic concentration and enhanced the cardiotonic effect of aconitine. CONCLUSION Aconitine had positive inotropic effect on dysfunctional isolated rat hearts; the combination of aconitine with potassium channel activator markedly widened the cardiotonic doses range of aconitine and enhanced its cardiotonic effect.