Short-term effects of ether, equithesin and droperidol/fentanyl on catecholamine and indolamine metabolism in the brain of the rat.

Levels of biogenic amines and their major metabolites were measured in the frontal cortex, dorsal striatum (caudate nucleus) and ventral striatum (nucleus accumbens and olfactory tubercle) of rats which had received anaesthetic or analgesic drugs or no treatment, shortly before decapitation. Apart from a reduced level of homovanillic acid in the ventral striatum after ether, no differences were observed between ether- or Equithesin-treated and untreated animals in the levels of dopamine, dihydroxyphenylacetic acid, homovanillic acid, 3-methoxytyramine, noradrenaline, serotonin or 5-hydroxyindoleacetic acid. The neuroleptic analgesic droperidol/fentanyl, on the other hand, increased the levels of dihydroxyphenylacetic acid in the frontal cortex and dorsal and ventral striatum and of homovanillic acid in the ventral striatum; additionally, a reduced level of serotonin was observed in the frontal cortex. It is concluded that both ether and Equithesin can be used as short-term anaesthetics prior to sacrificing rats, when the levels of biogenic amines are to be analyzed in the frontal cortex or ventral or dorsal striatum.