studia universitatis babeÅ-bolyai biologia 2

More documents

Recommendations

Info

C. SEVCENCU 8. Sevcencu, C., Patriciu, A., Chihaia, E., System for monitoring the total bioelectrical activity of isolated frog heart, "Abstr., 4th Natl. Conf. Biophys. (Cluj-Napoca, 1997)", 1997, 34. 9. Syme, D.A., Influence of extent of muscle shortening and heart rate on work from frog heart traberculae, "Am. J. Physiol.", 265, 1993, 310-319. 10. Syme, D.A., Josephson, R.K., Influence of muscle length on work from trabercular muscle of frog atrium and ventricle, "J. Exp. Biol.", 198, 1995, 2221-2227. 70
STUDIA UNIVERSITATIS BABEŞ-BOLYAI, BIOLOGIA, XLV, 2, 2000 EFECTUL DIGOXINEI ASUPRA UNOR PARAMETRI AI CONTRACŢIEI MIOCARDULUI VENTRICULAR DE BROASCĂ CĂLIN ARDELEAN ∗ , CRISTIAN SEVCENCU ∗ şi CLAUDIA KISS ∗ SUMMARY. – The Effect of Digoxin on Some Parameters of the Contraction of Ventricular Myocardium in Frog. The role of digoxin in affecting transmembrane calcium fluxes is well established in mammalian cardiac myocytes. In order to see whether digoxin also induces calciumrelated effects on ventricular parameters in ectotherms, we performed the present experiments on isolated frog hearts by means of a previously presented data acquisition system. Taking into consideration that the digoxininduced calcium disturbances would be reflected mainly in changes of the ventricular contractility, we have measured its classical parameters – contraction amplitude, contraction period, contraction plateau and relaxation period, as well as some original ones, such as contraction velocity, force, mechanical work and heart power. Our results are consistent with those obtained by others in mammalian hearts and demonstrate that digoxin has a positive inotropic effect on the frog ventricle. Thus, all the parameters mentioned above showed significant initial increases, followed by their stabilisation above the basic values during the second and the third time intervals. In terms of cardiac frequency, we have established a severe bradycardia which was not observed in mammals. Therefore, the conclusion of our study is that, like in mammals, digoxin affects the mechanical activity of the frog hearts, and its inotropic and chronotropic effects are probably due to changes induced by this agent in the calcium activity. Digoxina este un glicozid natural care face parte din categoria cardiotonicelor, acest compus fiind cunoscut şi utilizat de multă vreme în tratamentul unor afecţiuni cardiace caracterizate prin incapacitatea inimii de a asigura afluxul sangvin necesar unei oxigenări tisulare corespunzătoare. Plante medicinale cu conţinut bogat în glicozide cardiace erau cunoscute încă de acum 3000 de ani de către vechii egipteni. Astfel de agenţi au fost însă folosiţi sporadic şi cu consecinţe variabile până în secolul trecut, când William Withering (citat în [6]) a publicat o monografie, în care a descris, între altele, efectele clinice ale unor extracte digitalice. ∗ Universitatea "Babeş-Bolyai", Catedra de Fiziologie animală, 3400 Cluj-Napoca, România. E-mail: sevcr@biolog.ubbcluj.ro (C. Sevcencu)
Page 1 and 2:
ANUL XLV 2000 S T U D I A UNIVERSIT
Page 3 and 4:
STUDIA UNIVERSITATIS BABEŞ-BOLYAI,
Page 5 and 6:
APLICAŢIILE EMBRIOGENEZEI SOMATICE
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16: APLICAŢIILE EMBRIOGENEZEI SOMATICE
Page 23 and 24: STUDIA UNIVERSITATIS BABEŞ-BOLYAI,
Page 25 and 26: FLORA ŞI VEGETAŢIA DIN MLAŞTINA
Page 27 and 28: FLORA ŞI VEGETAŢIA DIN MLAŞTINA
Page 31 and 32: VEGETAŢIA PRECUATERNARĂ DE LA PRA
Page 37 and 38: N. TOMESCU, L. OLARIU The bibliogra
Page 39 and 40: N. TOMESCU, L. OLARIU R E F E R E N
Page 41 and 42: V. POPA These stations are: 1. The
Page 43 and 44: 44 V. POPA
Page 45 and 46: V. POPA The highest relative abunda
Page 49 and 50: MODIFICATIONS INDUCED BY CARBOPLATI
Page 55 and 56: C. PAŞCA et al. Cisplatin (Platino
Page 57 and 58: C. PAŞCA et al. F i g. 1. Urinary
Page 59 and 60: C. PAŞCA et al. provide support fo
Page 63 and 64: MONITORIZAREA SIMULTANĂ A EKG ŞI
Page 65: MONITORIZAREA SIMULTANĂ A EKG ŞI
Page 69 and 70: EFECTUL DIGOXINEI ASUPRA PARAMETRIL
Page 77 and 78: C. I. SICORA, M. DRĂGAN-BULARDA, I
Page 87 and 88: A. SAMUEL, S. KISS, M. ŞANDOR The
Page 89 and 90: 94 A. SAMUEL, S. KISS, M. ŞANDOR
Page 91 and 92: A. SAMUEL, S. KISS, M. ŞANDOR Maiz
Page 93 and 94: A. SAMUEL, S. KISS, M. ŞANDOR Tabl
Page 97 and 98: R E C E N Z I I prin această tehno
show all

studia universitatis babeÅ-bolyai biologia 2

Create successful ePaper yourself

Delete template?

Save as template?

studia universitatis babeÅ-bolyai biologia 2