Effects of drugs which influence noradrenergic activity on metenkephalin levels in specific brain areas

The effects of pretreatment with clonidine, an alpha 2 adrenoceptor agonist, and isobutylmethylxanthine, a phosphodiesterase inhibitor, were measured on the metenkephalin content of the locus coeruleus, the amygdala and the nucleus periventricularis thalamis of rat brain. No significant effect of either drug on metenkephalin content could be detected.