Abstract
An investigation of the pharmacological mechanism of the Straub tail reaction (STR) was made of the intracerebral (i.c.) injection of morphine. In addition, the effects of central muscle relaxants on the STR were examined. The STR was elicited by i.c. injection of morphine. Meprobamate, haloperidol, 1, 3-diphenyl-5-(2-dimethylaminopropionamide)-pyrazole [difenamizole] and β-(p-chlorophenyl)-γ-aminobutyric acid [baclofen] apparently decreased the STR by systemic administration. In mice injected i.c. with difenamizole or baclofen, moreover, the STR was noticeably inhibited. Especially, baclofen decreased the STR in the approximate one-thousandth of the dose by systemic administration. Thus it appears that the central nervous system may have a profound significance for the manifestation of the STR due to morphine in mice.
