Possible Interaction: Isoproterenol and Yohimbine

“In the presence of yohimbine, isoprenaline (1.2 μM) significantly increased stimulation-induced transmitter overflow, suggesting that in rat atria the facilitatory effect of isoprenaline mediated via prejunctional beta-adrenoceptors, is masked by the dominant influence of inhibitory alpha-2-adrenoceptors.”

“The effects of Clon and Iso and BRL 37344 were antagonized by yohimbine and propranolol, respectively.”

“Pretreatment with yohimbine caused a three to four-fold increase in plasma delta NPY-LI, which was slightly reduced both in the presence of isoprenaline (-39%) and propranolol (-27%).”

“The NE and isoprenaline actions were antagonized by yohimbine and propranolol, respectively.”

“Decreased cyclic AMP production at high concentrations of isoproterenol is blocked by the specific alpha 2-adrenergic antagonist, yohimbine , but not by the alpha 1-adrenergic antagonist, prazosin.”

“The differences observed in the dose-response curves of adenylate cyclase activity to isoproterenol or noradrenaline were prevented in the presence of clonidine (a alpha 2-agonist) or yohimbine (alpha 2-antagonist) respectively.”

“Further, yohimbine and tolazoline, alpha 2-adrenoceptor antagonists, augment the drinking response to both peripherally administered isoproterenol and angiotensin II.”

“ Yohimbine (1 times 10-6M) reduced the rate of beating to isoprenaline and to noradrenaline.”

“ Yohimbine enhanced the potentiating effect of isoproterenol on the STZ-induced diabetes.”