u-50488 and rimcazole

I.v. administration of U-50,488H after i.v. saline pretreatment produced occasional high-voltage EEG slow-wave bursts that were associated with relatively small increases in spectral power in the 2.5-7.5 Hz band as a spectral peak and with behavioral incidents of sedation, ataxia, ptosis, straub tail, hunching of the back, and backing-up. After pretreatment with the sigma antagonists rimcazole and DuPont Merck S-7389-4, U-50,488H administration produced significantly larger increases in absolute EEG spectral power, both over the 1-50 Hz range and in the 2.5-5.0 and 5.0-7.5 Hz bands, than after saline pretreatment; rimcazole pretreatment eliminated U-50,488H-induced incidents of ataxia, ptosis, hunching of the back and backing-up. In summary, effects of U-50,488H on EEG, EEG power spectra and behavior may reflect interactions between kappa opioid and sigma (non-opioid) receptor-effector systems.

Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Animals; Antihypertensive Agents; Antipsychotic Agents; Behavior, Animal; Carbazoles; Drug Interactions; Electroencephalography; Female; Injections, Intravenous; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, sigma