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Changes of membrane-bound and soluble proteins of frontal rat brain cortex induced by morphine
Ujčíková, Hana
The aim of this Ph.D. thesis was to analyze the morphine-induced changes of frontal brain cortex protein composition in rats exposed to increasing doses of morphine (10-50 mg/kg) for prolonged period of time (10 days). The first part of this work was oriented to the analysis of the phenomenon of hypersensitization/superactivation of adenylyl cyclase (AC), which is regarded as one of the crucial molecular mechanisms causing drastic pathological consequences of drug addiction. The increase of AC activity represents a "compensatory" response and is functionally related to the desensitization of G protein response to prolonged morphine exposure of target cells. The clear desensitization of µ-OR- and δ-OR-stimulated G protein response by morphine was demonstrated in our laboratory by analysis of the dose-response curves of DAMGO and DADLE-stimulated, high-affinity [35 S] GTPγS binding in plasma membranes isolated from frontal brain cortex of rats exposed to morphine according to the same protocol as that used in my Ph.D. thesis (10-50 mg/kg, 10 days). The κ-OR-stimulated [35 S] GTPγS binding was unchanged. It has been determined the amount of all AC isoforms (AC I-IX) in plasma membranes (PM) isolated from control and morphine-treated rats which were sacrificed 24 hours since the last dose of morphine....
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Changes of membrane-bound and soluble proteins of frontal rat brain cortex induced by morphine
Ujčíková, Hana ; Svoboda, Petr (advisor) ; Mikšík, Ivan (referee) ; Farghali, Hassan (referee)
The aim of this Ph.D. thesis was to analyze the morphine-induced changes of frontal brain cortex protein composition in rats exposed to increasing doses of morphine (10-50 mg/kg) for prolonged period of time (10 days). The first part of this work was oriented to the analysis of the phenomenon of hypersensitization/superactivation of adenylyl cyclase (AC), which is regarded as one of the crucial molecular mechanisms causing drastic pathological consequences of drug addiction. The increase of AC activity represents a "compensatory" response and is functionally related to the desensitization of G protein response to prolonged morphine exposure of target cells. The clear desensitization of µ-OR- and δ-OR-stimulated G protein response by morphine was demonstrated in our laboratory by analysis of the dose-response curves of DAMGO and DADLE-stimulated, high-affinity [35 S] GTPγS binding in plasma membranes isolated from frontal brain cortex of rats exposed to morphine according to the same protocol as that used in my Ph.D. thesis (10-50 mg/kg, 10 days). The κ-OR-stimulated [35 S] GTPγS binding was unchanged. It has been determined the amount of all AC isoforms (AC I-IX) in plasma membranes (PM) isolated from control and morphine-treated rats which were sacrificed 24 hours since the last dose of morphine....
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Changes of membrane-bound and soluble proteins of frontal rat brain cortex induced by morphine
Ujčíková, Hana
The aim of this Ph.D. thesis was to analyze the morphine-induced changes of frontal brain cortex protein composition in rats exposed to increasing doses of morphine (10-50 mg/kg) for prolonged period of time (10 days). The first part of this work was oriented to the analysis of the phenomenon of hypersensitization/superactivation of adenylyl cyclase (AC), which is regarded as one of the crucial molecular mechanisms causing drastic pathological consequences of drug addiction. The increase of AC activity represents a "compensatory" response and is functionally related to the desensitization of G protein response to prolonged morphine exposure of target cells. The clear desensitization of µ-OR- and δ-OR-stimulated G protein response by morphine was demonstrated in our laboratory by analysis of the dose-response curves of DAMGO and DADLE-stimulated, high-affinity [35 S] GTPγS binding in plasma membranes isolated from frontal brain cortex of rats exposed to morphine according to the same protocol as that used in my Ph.D. thesis (10-50 mg/kg, 10 days). The κ-OR-stimulated [35 S] GTPγS binding was unchanged. It has been determined the amount of all AC isoforms (AC I-IX) in plasma membranes (PM) isolated from control and morphine-treated rats which were sacrificed 24 hours since the last dose of morphine....
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The study of membrane receptors by radioligands binding
Rejhová, Alexandra ; Hudeček, Jiří (advisor) ; Hejnová, Lucie (referee)
Drug addiction, opiates respectively, is a social problem which seriousness is currently on the rise. One of key elements causing addiction is tolerance to increasing doses of drug causing abstinence syndrome during withdrawal and craving. Opioid receptors are members of a large group of receptors coupled with heterotrimeric G-proteins (GPCR), whose properties can be investigated using agonist- stimulated binding [35 S] GTPγS. Many extracellular signals are transferred into a cell through GPCR. Opioid receptor agonists inhibit the activity of adenylyl cyclase and are coupled with G-protein group Gi/Go. This work is devoted to the study of changes in isolated plasma membranes of rat forebrain containing opioid receptors of healthy subjects with membranes acquired from morphine addicted subjects. The rats were long-term morphine treated in increasing doses, to develop the dependency. The comparison is done firstly by binding of [3 H]ouabain to Na,K-ATPase, which proves to be a negative standard of changes, secondly by binding [35 S]GTPγS to G-proteins, thereby providing the functional activity of G-protein in stimulating the binding by the agonist of δ-opioid receptors DADLE or agonist of µ-opioid receptors DAMGO. Furthermore, it has been studied the influence of prostaglandin E1 on binding [35...
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