Frog Heart Monomeric Hemoglobin

Author(s):  
Nobuyo Maeda ◽  
Walter M. Fitch
Keyword(s):  
Author(s):  
Sarella Prakash Nathaniel Kumar ◽  
Kanthal L.K. ◽  
Durga S ◽  
Achutha Rama Raju D ◽  
Satyavati K

Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas, where herbal medicine is mainly the source of health care system. Many of these herbs havenot been assessed for safety or toxicity to tissue or organs of the mammalian recipients. An attempt is made to prove the efficacy of Sida cordifolia Linn., (a traditional medicinal plant chosen on the basis of ethnomedical knowledge) for its Cardiotonic, Antibacterial and Anthelmintic activities. Sida cordofolia Linn., is used traditionally, inter alia, in the treatment of various infections, asthma, diarrhoea, heart and stomach disorders. Cardiotonicactivity is performed using isolated Frog Heart Perfusion Technique. Antibacterial activity of the whole plant extracts were assessed by Agar well diffusion method against the strains of Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. Anthelmintic activity was studied against Pheretima posthuma. Phytochemical screening of powdered plant material revealed thepresence of some secondary metabolites such as alkaloids, saponins, tannins, glycosides and flavonoids. Results indicated that methanol, chloroform, aqueous extracts have significant cardiotonic activity but less than standard drugs. Methanol and Aqueous extracts showed high antibacterial activity and anthelmintic activity than the standard drugs. In a nutshell, we can conclude that the methanol and aqueous fractions of Sida cordifolia Linn., had a profound antibacterial and anthelmintic effect eventhough it possessed very significant cardiotonic activity. This validates its continuous usage in ethnomedicine. This plant could be developed into cheap, safe and culturally acceptable standardized herbal products and may serve as asource of new molecules for broad-spectrum antimicrobial and anthelmintic agent.


2018 ◽  
Vol 80 (4) ◽  
pp. 578-582 ◽  
Author(s):  
Nobuaki KON ◽  
Nozomu ABE ◽  
Masahiro MIYAZAKI ◽  
Hajime MUSHIAKE ◽  
Itsuro KAZAMA
Keyword(s):  

1956 ◽  
Vol 41 (2) ◽  
pp. 129-132 ◽  
Author(s):  
G. A. Erzina ◽  
V. V. Mikhailov
Keyword(s):  

1981 ◽  
Vol 213 (1192) ◽  
pp. 303-324 ◽  

Effects of caffeine on contractile tension and on intracellular action and resting potentials were examined in single frog heart trabeculae suspended in a rapid perfusion chamber. Trabeculae from atria responded more readily than those from ventricles and were therefore studied in greater detail. Both the contracture and twitch responses, the one obtained at high (>10 mM), the other at low (<10mM) caffeine concentrations, consisted of a transient tension rise followed by a maintained phase of lower, but still enhanced, tension. The hypothesis was tested that the transient response is due to the release of calcium from the sarcoplasmic reticulum (s.r.), whereas the maintained tension results from enhanced calcium influx through the cell surface. Support for these ideas was obtained by examining the response to step changes of external calcium and caffeine concentrations, applied in various combinations, simultaneously and in sequence. It also emerged that the effects on twitch tension of calcium derived from (a) s.r. discharge and ( b) influx are additive, to a first approximation. A test procedure for monitoring the s.r. store content was evolved to follow the accumulation of s.r. calcium after a preceding depletion. The results obtained, and others, suggest that the s.r. calcium pump can be operative in atrial heart cells and capable, after store depletion, of reabsorbing up to some 40 % of calcium activating a twitch, the remainder being, presumably, extruded from the cells.


2002 ◽  
Vol 293 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Antigone Lazou ◽  
Catherine Gaitanaki ◽  
Spiros Vaxevanellis ◽  
Anastasia Pehtelidou

1994 ◽  
Vol 5 (6) ◽  
pp. 499-504 ◽  
Author(s):  
Martin-Pierre Sauviat ◽  
Marie-Thérèse Moré ◽  
Jean-François Verbist

1992 ◽  
Vol 70 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Maria Touraki ◽  
Antigone Lazou

The effect of adenosine on the calcium paradox in the isolated frog heart was studied. Addition of adenosine during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein and creatine kinase release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that adenosine protected frog myocardial cells by reducing the massive calcium influx during reperfusion possibly through an action on calcium channels. Adenosine exerted its action in a dose-dependent manner; a concentration of 10 μM adenosine provided maximum protection of myocardial cells against the calcium paradox damage. Higher concentrations of adenosine produced side effects on both electrical and mechanical activity. These results are discussed in terms of the possible mechanism involved in the protective effect of adenosine.Key words: calcium paradox, adenosine, frog heart.


1972 ◽  
Vol 11 (1) ◽  
pp. 179-203
Author(s):  
SALLY G. PAGE ◽  
R. NIEDERGERKE

Two structures of physiological interest in frog heart ventricles have been examined in detail: (a) the layer of endothelial cells which encloses each bundle of heart fibres, and (b) the sarcoplasmic reticulum (SR) inside the heart fibres. Some additional observations on fibre sizes and types have been made. Movement across the endothelial cell layer of molecules (molecular or ionic size ≤ 12.5 nm) occurs through narrow clefts separating each endothelial cell from its neighbour. This conclusion results from experiments made with the extracellular markers ferritin and horseradish peroxidase. A diffusion equation describing the movement of solutes into and out of the fibre bundle has been derived using several geometrical parameters, such as the length and width of the clefts and the size of the extracellular aqueous space inside the bundle, all of which were determined from electron micrographs of the tissue. The theoretical solution for a stepwise change of external calcium concentration gives a halftime of 2.3 s (± 0.8 s, S.D. of 13 bundles) for diffusion equilibrium at the surface of the heart fibres; this value, however, is likely to be an overestimate, by some 20-30 %, on account of several systematic errors which are described. The sarcoplasmic reticulum in heart fibres consists of a network of thin tubules which partially encircle the myofibrils at Z-line level and also form occasional longitudinal connexions. Branches extend to peripheral regions of the cell and terminate in close apposition to the inner surface of the cell membrane. The volume of the SR is estimated to be approximately 0.5% of the myofibrillar volume of the cells. Cross-sectional areas of heart fibres (and also their shapes) vary considerably, from less than 2 to more than 100 µm2 (average 17.4 µm2).Fibres of large size and small surface/volume ratio contain many fewer myofibrils and more glycogen granules than fibres of the same size but larger surface/volume ratio. Physiological implications of these results are discussed.


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