Author/Editor     Fras, Zlatko
Title     Vzroki povečanja fibrinolitične aktivnosti krvi med telesno aktivnostjo in farmakološkim spodbujanjem
Type     monografija
Place     Ljubljana
Publisher     Medicinska fakulteta
Publication year     2007
Volume     str. 134
Language     slo
Abstract     Background. The mechanisms of increases of tissue-type plasminogen activator (t-PA), the most important physiologic activator of fibrinolysis, in response to acute stimuli, i.e. physical exercise, mental stress, venous occlusion of an extremity and pharmacological stimulation with drugs, such as adrenaline and vasopressine and their derivatives/analogues, are still incompletely understood. Regarding exercise, most of the studies have suggested that exercise stimulates increased endothelial secretion of t-PA, while some recent reported that exercise decreases clearance of t-PA. The mechanisms of action of the pharmacologic stimuli seem more clear, and it is believed that they are mainly operating through increasing endothelial release of t-PA, and also different receptor mechanisms for this actions were elucidated. Desmopressin (1-desamino-B-D-arginine vasopressin, DDAVP) is a synthetic analogue of the human neurohypophyseal hormone vasopressin and a potent agonist of V2receptors. In experimental studies it was shown that DDAVP induces a massive acute flow independent release of t-PA. Aim of the study. The main purpose of this study was to evaluate the separate and joint effects of DDAVP infusion and sustained submaximal exercise on the fibrinolytic system and hepatic clearance of t-PA. Subjects and methods. We studied the relationship between DDAVP infusion, sustained submaximal exercise, increased t-PA levels and hepatic clearance of t-PA. Six healthy male volunteers exercised for 35 minutes while receiving constant rate infusions of either placebo or DDAVP in doses of 0.4 wg/kg for 15 minutes or 1.4microg/kg for 80 minutes (started 30 minutes before exercise). On two other occasions the volunteers received only DDAVP infusions. Liver blood flow (LBF) was estimated simultaneously by constant rate indocyanine green infusion. (Abstract truncated at 2000 characters)
Descriptors     EXERCISE
FIBRINOLYSIS
PLASMINOGEN ACTIVATORS
DESMOPRESSIN
PLASMINOGEN ACTIVATOR INHIBITOR 1
ADULT
LIVER CIRCULATION
INDOCYANINE GREEN
ANTIPLASMIN