[The analgesic action of clofelin administered via the cerebral ventricles and the theca medullaris spinalis].

In experiments on conscious rats it was found that clopheline (10-50 micrograms) administered intracerebroventricularly and intrathecally inhibits nociceptive shifts of arterial blood pressure and predominantly depresses segmental pain reflex in the tail-flick test. Pharmacological analysis showed that the inhibiting effect of clopheline on various manifestations of pain was due to the activation of alpha 1-adrenoceptors of the spinal cord, while in the brain the processes triggered through alpha 2-adrenoceptors play the leading role.