Effect of ω-conotoxin and verapamil on antinociceptive, behavioural and thermoregulatory responses to opioids in the rat
| Autor: | Eleonora Pistacchio, Giovanna Murari, Sergio Ferri, Paolo Govoni, Santi Spampinato, Ester Speroni, Carlo Romagnoli |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Narcotics medicine.medical_specialty Enkephalin Dynorphin Catalepsy Rats Sprague-Dawley chemistry.chemical_compound omega-Conotoxin GVIA Internal medicine medicine Animals Opioid peptide Pharmacology Behavior Animal Chemistry Brain Enkephalins Enkephalin Ala(2)-MePhe(4)-Gly(5) Hypothermia Calcium Channel Blockers medicine.disease Rats DAMGO Endocrinology Verapamil Hyperalgesia Analgesia medicine.symptom Enkephalin D-Penicillamine (2 5) Peptides Body Temperature Regulation medicine.drug |
| Zdroj: | European Journal of Pharmacology. 254:229-238 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/0014-2999(94)90459-6 |
| Popis: | This study with the rat evaluated the contribution of omega-conotoxin GVIA-(omega-CgTx) and verapamil-sensitive Ca2+ channels in behavioural, antinociceptive and thermoregulatory responses to intracerebroventricular (i.c.v.) injection of [D-Ala2,NMePhe4,Gly-ol5]enkephalin (DAMGO), [D-Pen2,D-Pen5]enkephalin (DPDPE) and dynorphin A-(1-17), which are selective agonists for putative mu, delta and kappa-opioid receptors, respectively. The rats treated with omega-CgTx (8-32 pmol i.c.v.) showed transient, dose-dependent shaking behaviour, hyperalgesia and hypothermia which gradually disappeared within 4 h. The behaviour of the rats was normal by 24 h. Histological examination of brain sections showed morphological alterations of neurons in the hippocampus, medial-basal hypothalamus and pyriform cortex. antinociception, catalepsy and thermoregulatory responses elicited by DAMGO (0.4 and 2.0 nmol) were significantly prolonged and potentiated by verapamil (20 pmol i.c.v. 15 min before) or omega-CgTx (8 pmol 24 h before). Antinociception and hypothermia induced by DPDPE were antagonized by verapamil and omega-CgTx, whereas only omega-CgTx prevented the behavioural arousal observed after DPDPE. Similarly, hypothermia induced by dynorphin A-(1-17) (5.0 nmol) and by the kappa-opioid receptor agonist U50,488H (215 nmol) was antagonized by the two Ca2+ channel blockers but only omega-CgTx prevented the barrel rolling and bizarre postures caused by the opioid peptide. |
| Databáze: | OpenAIRE |
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