The adenosinergic system is involved in sensitization to morphine withdrawal signs in rats—neurochemical and molecular basis in dopaminergic system

Abstrakt

Experimental data informs that not only do the dose and time duration of dependent drugs affect the severity of withdrawal episodes. Previous withdrawal experiences may intensify this process, which is referred as sensitization to withdrawal signs. Adenosine and dopamine (DA) receptors may be involved in this sensitization. Rats were continuously and sporadically treated with increasing doses of morphine for 8 days. In rats, sporadically treated with morphine, morphine administration was modified by adding three morphine-free periods. Adenosine agonists were given during each of the morphine-free periods (six injections in total). On the 9th day, morphine was injected. One hour later, naloxone was administered to induce morphine withdrawal signs. Then, the animals were placed into cylinders and the number of jumpings was recorded. Next, the rats were decapitated and brain and brain structures (striatum, hippocampus, and prefrontal cortex) were dissected for neurochemical, molecular, and immunohistochemical experiments within DAergic pathways. We demonstrated that previous experiences of opioid withdrawal intensified subsequent withdrawal signs. Adenosine ligands attenuated the sensitization to withdrawal signs. In a neurochemical study, the release of DA and its metabolites was impaired in all structures. Significant alterations were also observed in mRNA and protein expression of DA receptors. Results demonstrate that intermittent treatment with morphine induces alterations in the DAergic system which may be responsible for sensitization to morphine withdrawal signs. Although adenosine ligands attenuate this type of sensitization, they are not able to fully restore the physiological brain status.

Autorzy

Joanna Listos
Joanna Listos
Irena Baranowska-Bosiacka
Irena Baranowska-Bosiacka
Agnieszka Wąsik
Agnieszka Wąsik
Sylwia Talarek
Sylwia Talarek
Maciej Tarnowski
Maciej Tarnowski
Małgorzata Łupina
Małgorzata Łupina
Lucyna Antkiewicz-Michaluk
Lucyna Antkiewicz-Michaluk
Izabela Gutowska
Izabela Gutowska
Marta Tkacz
Marta Tkacz
Anna Pilutin
Anna Pilutin
Jolanta Orzelska-Górka
Jolanta Orzelska-Górka
Dariusz Chlubek
Dariusz Chlubek
Sylwia Fidecka
Sylwia Fidecka
artykuł
PSYCHOPHARMACOLOGY
Angielski
2016
233
12
2383
inne
CC BY 4.0 Uznanie autorstwa 4.0
ostateczna wersja opublikowana
w momencie opublikowania
35
3,308
6
6