Various divalent cations protect the isolated perfused pigeon heart against a calcium paradox
Φόρτωση...
Ημερομηνία
Συγγραφείς
Gaitanaki, C.
Labrakakis, C.
Papazafiri, P.
Beis, I.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Comp Physiol B
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The protective effects of various divalent cations against the irreversible damage of myocardium, a phenomenon termed "the Ca2+-paradox", were examined in the isolated perfused pigeon heart. All cations examined were added at a concentration of 200 micromol l(-1) in the "calcium-free" medium. In hearts perfused with low calcium, upon normal calcium repletion, the maximal recovery of the contractile tension (in the 2nd minute) was approximately 115% and the recovery obtained at the end of reperfusion was 81.5% (compared to the equilibration period value). From the other divalent cations examined, the presence of cobalt, nickel, manganese or barium during calcium depletion powerfully protected the pigeon heart. Upon calcium repletion, the maximal recovery of contractile tension was approximately 60%, 76.5%, 100% and 85%, the recovery estimated at the end of reperfusion was 40%, 12%, 70% and 53%, and the resting tension estimated at the end of reperfusion was 2.69+/-0.18 g, 6.40+/-0.50 g, 1.20+/-0.10 g and 1.90+/-0.10 g for cobalt, nickel, manganese and barium, respectively. On the contrary, strontium exerted no protective effects. The protective effects were also indicated by reduced total protein and lactate dehydrogenase activity release into the effluent perfusate and maintenance of electrical activity. The effectiveness of the added divalent cations (with the exception of strontium) showed a strong dependence upon their ionic radius. The most potent inhibitors of this phenomenon in the pigeon heart were the divalent cations having an ionic radius closer to the ionic radius of calcium. These results are discussed in terms of the possible mechanisms involved in the protective effects of these cations.
Περιγραφή
Λέξεις-κλειδιά
Animals, Calcium/*metabolism, Cations, Divalent/chemistry/metabolism/*pharmacology, Columbidae/metabolism/*physiology, Electrocardiography, Heart/*drug effects/physiology, L-Lactate Dehydrogenase/metabolism, Myocardial Contraction/*physiology, Myocardiu
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/15088115
http://link.springer.com/content/pdf/10.1007%2Fs00360-004-0423-7.pdf
http://link.springer.com/content/pdf/10.1007%2Fs00360-004-0423-7.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών