Possible Interaction: Neuropeptide Y and Yohimbine

“Many classical pharmacological agents including guanethidine, clonidine, yohimbine , angiotensin II, nicotine and desipramine influence NPY release.”

“Here, we examined whether neuropeptide Y (NPY), an endogenous anti-stress mediator, blocks reinstatement of alcohol-seeking induced by the pharmacological stressor yohimbine.”

“Within this network, both yohimbine and NPY potently induced neuronal activation, and their effects were additive, presumably indicating activation of excitatory and inhibitory neuronal populations, respectively.”

“Neuropeptide Y, but not peptide YY, inhibited the high K(+)-stimulated tetrodotoxin-resistant release of acetylcholine, while the inhibitory effect of neuropeptide Y disappeared after treatment with yohimbine.”

“The effect of the alpha 2-adrenoceptor agonist clonidine, the antagonists prazosin (alpha 1 selective) and yohimbine (alpha 2 selective) and the beta-adrenoceptor antagonist propranolol were all shown to modulate the evoked release of NPY.”

“ Yohimbine , an α2‐adrenergic antagonist, blocked NPY inhibition of isoproterenol‐stimulated cAMP accumulation.”

“doses of yohimbine rose plasma NPY concentrations.”

“In contrast, NPY infused concomitantly with prazosin did not increase MBH-GnRH release (… vs. 0.78 +/- 0.19 pg/ml; p greater than 0.05) whereas NPY … yohimbine did stimulate GnRH secretion (1.15 +/- 0.13 vs. 2.65 +/- …; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)”

“ Yohimbine alone tended to increase the NPY mRNA level after 24 h. 4 The recovery/increase in the NPY mRNA level in the adrenal gland after 5 days treatment with clonidine was similar to its increase after treatment with reserpine (0.5 mg kg−1, i.p.,”

“Conditions that increase the biophase concentration of norepinephrine, longer stimulation trains or application of yohimbine , decreased the potentiation by NPY , although in the presence of cocaine potentiation by NPY was unchanged.”

“Whereas IIIV pretreatment with phentolamine (71 nmol), a nonselective alpha-adrenoceptor antagonist, or prazosin (9.5 nmol), …-adrenoceptor antagonist, was without effect on NPY-induced feeding behavior, pretreatment with the alpha 2-adrenoceptor antagonist yohimbine (15 nmol) … effects of NPY or epinephrine on both food …%) and local eating rate.”