Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Antinociceptive effects of morphine in neonatal 5,7-dihydrotryptamine lesioned rats:the role of nitric oxide

100%
Krzascik P., Kolomanska P., Zajda M., Papasz A.
Acta Neurobiologiae Experimentalis
|
2005
|
tom 65
|
nr 3
2

Androsterone has rewarding and aversive prosperities and alters the rewarding effect of cocaine in the conditioned place preference procedure (CPP)

100%
Zajda M., Krzascik P., Majewska M.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
Our previous study showed that the neurosteroid dehydroepiandrosterone sulfate (DHEAS) alters the rewarding effects of cocaine. Because DHEAS is metabolized to androsterone, which has opposite synaptic activity, we wondered about contribution of androsterone to the above phenomenon. Here we examined androsterone’s effect on the rewarding properties of cocaine in CPP test. Male Wistar rats (250–300 g) were used. The CPP procedure consisted of pre-conditioning, conditioning and post-conditioning phases. Drug injections were done i.p. Androsterone alone was rewarding at doses 1 mg/kg and 10 mg/kg, while the dose of 40mg/kg was visibly aversive. Cocaine had a biphasic dose-dependent rewarding effect (inverted U type): the doses 5 and 10 mg/kg were rewarding, while at dose 20 mg/kg, cocaine rewarding effect was lost. Pretreatment with 1mg/kg of androsterone increased the rewarding effect of all cocaine doses, especially the dose of 20 mg/kg, but the rewarding dose of 10 mg/ kg of androsterone had no effect on the rewarding prosperities of cocaine. All doses of cocaine decreased the aversive effect of 40 mg/kg of androsterone. Androsterone per se has a biphasic rewarding-aversive effects in the CPP test and infl uences the rewarding properties of cocaine, which might be explained by two mechanisms: potentiation of reward at low doses and reduction of the aversive effect of the high doses. Funded by EC grant MEXCCT-2006-42371 to M.D. Majewska.
3

Interaction of neurosteriods-dehydroepiandrosterone sulphate (DHEAS) and androsterone-with cocaine in behavioral despair test (PORSOLT) in rats

100%
Krzascik P., Zajda M., Majewska M.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
Previous studies showed that high plasma levels of endogenous DHEAS correlated with resiliency and ability of cocaine addicts to maintain prolonged abstinence after the therapy (Wilkins et al. 2005), while addicts treated with high dose of exogenous DHEA used more cocaine that those administered placebo (Shoptaw et al. 2004). Such ambiguous outcomes could be due to mixed actions of DHEAS and its metabolite, androsterone, which have opposite neuronal activities. Here we examined acute effects of both neurosteroids in Porsolt test and their interactions with 5 mg/kg of cocaine – the dose reported to have antidepressive action, but which does not infl uence locomotor activity in the open fi eld. Wistar rats (250-300 g) were used. All substances were injected i.p.; steroids 30 min and cocaine 5 minutes before the test, which measures locomotor activity of rats in narrow water containers. Cocaine at dose 5 mg/kg signifi cantly increased rats’ locomotor activity in the Porsolt test. Neither DHEAS (1, 5, 10, 40, 80 mg/kg) nor androsterone (0,1, 1, 10, 40 mg/kg) per se had any effect on activity in this test. DHEAS dose-dependently potentiated the effect of cocaine, but androsterone had no infl uence on this cocaine action. Acutely administered DHEAS appears to increase antidepressive effects of cocaine, but androsterone has no such infl uence. Funded by EC grant MEXC-CT-2006-42371 to M.D. Majewska.
4

Dehydroepiandrosterone sulphate (DHEAS) is rewarding and alters the rewarding effect of cocaine in the conditioned place preference procedure (CPP)

100%
Zajda M., Krzascik P., Majewska M.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
DHEAS is endogenous allosteric antagonists of the GABA(A) receptor and has other direct and indirect actions in CNS. It is metabolized to other neuroactive steroids. Prior studies revealed an ambiguous role of DHEA(S) in cocaine dependence, suggesting interactions with cocaine effects in the brain. This preclinical study was undertaken to evaluate direct infl uence of DHEAS on the rewarding effects of cocaine, using the CPP test in rats. Male Wistar rats (250–300 g) were used. The conditioned place preference experiment consisted of preconditioning conditioning and post-conditioning phases. Drug injections were done i.p. only during the conditioning phase. Cocaine had a biphasic dose-dependent rewarding effect (inverted U type). The doses 5 and 10 mg/kg were clearly rewarding, as they increased rats’ preference for cocaine injection site, while at the dose 20 mg/kg, cocaine rewarding effect was lost. DHEAS alone had a similar biphasic rewarding effect (the effect of 40 mg/kg was maximal and statistically signifi cant). Pretreatment of rats with 40 mg/kg of DHEAS before injection of cocaine noticeably changed its rewarding effect, shifting cocaine dose response curve to the left. DHEAS, per se has rewarding properties and it enhances the rewarding effects of low doses of cocaine, but decreases the rewarding effect of higher doses of cocaine. Funded by EC grant MEXC-CT-2006-42371 to M.D. Majewska.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.