Possible Interaction: Dopamine and Yohimbine

“In analogy, yohimbine enhances FCX levels of DA and NAD, yet suppresses those of 5‐HT, the latter effect being antagonized by WAY100,635.”

“While fluparoxan selectively enhances hippocampal noradrenaline (NAD) turnover, yohimbine also enhances striatal dopamine (DA) turnover and suppresses striatal turnover of 5‐HT.”

“Similarly to neuroleptic agents, yohimbine reduced striatal acetylcholine concentrations and counteracted the dopamine (10(-5) M)-induced inhibition of the potassium-evoked release of [3H]acetylcholine from slices of caudate nucleus.”

“RESULTS Both oral domperidone and yo imbine in duced a significant increase in both plasma norepinephrine and plasma dop amine. ”

“ Yohimbine inhibits tryptophan,3may stimulate serotonin receptors,4and, above …, may induce a preferential destruction of newly synthesized dopamine and a depletion of stored noradrenaline.5Thus, when using such a complex pharmacologic tool as yohimbine, it is not possible to draw any direct clinical inference by ascribing it to only”

“ Dopamine (DA) … by yohimbine in the WT but unaffected in the KO mice, suggesting that NPY-Y2 receptor exerts a direct control over both the tonic and … and that, although the anxiety-like behavior of these NPY-Y2 KO mice is unaltered, there are clear modifications of DA dynamics.”

“Even after blocking the alpha(2)-adrenoceptor with yohimbine , the inhibitory effect of DA still remained, indicating separate action of DA from AD or NA.”

“Interestingly, a behaviorally ineffective dose of yohimbine markedly reduced the inhibitory effects of DA when injected 15min before.”

“The turnover of dopamine and noradrenaline in the mouse brain, as assessed by the disappearance of catecholamines following treatment with the tyrosine hydroxylase inhibitorα-methyltyrosine, was accelerated by yohimbine with a peak effect after 10 mg/kg intraperitoneally.”

“ Yohimbine did not stimulate motor activity following 10 mg/kg and it retarded the turnover of dopamine following 30 mg/kg.”

“completely antagonized the stimulatory effect of yohimbine on motor activity and on dopamine turnover but it somewhat potentiated the stimulatory effect on the turnover of noradrenaline.”

“Both sulpiride and domperidone, but not yohimbine , also antagonized the inhibitory effect of dopamine on the indomethacin-induced intestinal hypermotility.”

“ Yohimbine (alpha2-adrenoceptor antagonist, 0.3 micromol l-1) significantly (P<0.05) attenuated the inhibitory effects of dopamine and caused an upward shift in the concentration-response curves in the vas deferens and the urinary bladder.”