Author/Editor     Kužner, Jernej
Title     Zaščitne snovi in postopki pri ohranjanju funkcionalne sposobnosti izolirane koronarne arterije po hipoksiji
Type     monografija
Place     Ljubljana
Publisher     Univerza v Ljubljani, Medicinska fakulteta
Publication year     2005
Volume     str. 80
Language     slo
Abstract     Background. Functionality of cardiomyocytes impaired after ischemia-reperfusion may be preserved by using protective substances or by preconditioning. Hypoxia - reoxygenation causes alterations in contractions and relaxations of coronary artery as well. The endothelium-dependent relaxation may be mediated by nitric oxide (NO) and prostacyclin (PGI2) or by endothelium-derived hyperpolarisation factor (EDHF). The combination of substances used for precontraction and subsequent relaxation determines which of the two ways will predominate. Aim and hypothesis. We tried to confirm the hypothesis that the functionality of the porcine left anterior descending coronary artery (LAD) after hypoxia - reoxygenation may be preserved by some substances or by preconditioning. Therefore, we evaluated the influence of long-lasting hypoxia on the functionality of LAD as well as possible protective effects of some substances and of some procedures as well. Methods. Rings (3 - 5 mm wide) of LAD were placed in 10-mL organ baths, filled with oxygenated or nitrogenated Krebs-Henseleit (K-H) solution at 37°C. Contractile responses to 20 mM KC1 before and after 10-, 40- and 60-min hypoxia and 30-min reoxygenation were measuerd with isometric mechano-electric converter and compared. In addition, relaxations of the KCl- or U46619 (thromboxane analogue)-precontracted rings caused by substance P, bradykinin, adenosine or prostaglandin E1 before and after hypoxia - reoxygenation in the presence of indomethacin and Nomega-nitro-L-arginine (which inhibit cyclooxygenase and NO-synthase, respectively) and without these substances were compared. Relaxation after 60-min hypoxia and 30-min reoxygenation (H-R) was compared with relaxations after H-R following incubation of rings in K-H solution containing lacidipine, cerebrocrast or palmiltoylethanolamide and after hypoxic or pharmacological preconditioning. (Abstract truncated at 2000 characters).
Descriptors     CORONARY VESSELS
VASOCONSTRICTION
POTASSIUM CHLORIDE
ANOXIA
VASODILATION
SUBSTANCE P
BRADYKININ
ADENOSINE
PROSTAGLANDINS E, SYNTHETIC
SWINE
RECEPTORS, THROMBOXANE
CYCLOOXYGENASE INHIBITORS
NITRIC-OXIDE SYNTHASE
CALCIUM CHANNEL BLOCKERS