Author/Editor     Virant, Mojca
Title     Vpliv izbranih zaviralcev angiotenzinskega sistema na poškodbe hipoksije-reoksigenacije izolirane prašičje koronarne arterije
Type     monografija
Place     Ljubljana
Publisher     Univerza v Ljubljani, Medicinska fakulteta
Publication year     2006
Volume     str. 54
Language     slo
Abstract     BACKGROUND. Ability of vessels to relax and to contract is impaired after prolonged exopsure to ishemia. Ability of vessels to relax can be perserved by using protective substances or by preconditioning. Inhibitors of angiotensin system protect cardiovascular system from ishemic injuries. The degree of protection of isolated coronary arteries from injuries caused by hypoxiareoxygenation (H-R) can be demonstrated by the degree of relaxation of vessels during reoxygenation mediatetd by endothelium-derived hyperpolarisation factor (EDHF). AIM. We tried to show on isolated porcine coronary arteries that certain drugs, which induce preconditioning and protect vessels from injuries of H-R in normal physiologic conditions in vivo, may also protect isolated vessels from injuries of H-R under profound hypothermia (4°C) while certain other drugs may not. With cold Krebs-Henseleit solution (KH) we altered the bradykinin functioning. With the use of thromboxane analogue U-46619 we tried to determine the role of thromboxane system. HYPOTHESIS. Losartan, inhibitor of angiotensin II on receptors AT1, will preserve relaxation of the porcine coronary arteries with substance P after exposure to H-R under profound hypothermia, while captopril will not preserve the relaxation in such conditions. METHODS. Arterial rings were dissected from left anterior decsending porcine coronary artery and placed in Krebs-Henseleit solution (KH). With preliminary tests we studied the effects of these drugs on KCl induced contraction of coronary arteries. After this we contracted rings with 60 mM KCl (to obtain reference contractions) and incubated them with indomethacine and LNNA (COX and NOS inhibitors). Relaxation of the rings was achieved with cumulative addition of substance P on the rings precontracted with 50 nM U-46619 (thromboxane analogue). Relxation was mediated by EDHF. (Abstract truncated at 2000 characters)
Descriptors     CORONARY VESSELS
ANGIOTENSIN-CONVERTING ENZYME INHIBITORS
ANOXIA
VASOCONSTRICTION
POTASSIUM CHLORIDE
SUBSTANCE P
SWINE