title: RX781094 a potent and selective alpha 2-adrenergic antagonist. Effects in adipocytes and hepatocytes.
abstract: The potency and selectivity of RX781094, 2-(2-(1,4-benzodioxanyl]-2-imidazoline HCl, as alpha 1- and alpha 2-adrenergic antagonist was studied using rat hepatocytes and hamster adipocytes. The alpha 1-adrenergic stimulation of ureogenesis produced by epinephrine in rat hepatocytes was slightly diminished by 10(-4) M RX781094. On the contrary the alpha 2-adrenergic effect of epinephrine in hamster adipocytes (inhibition of adenylate cyclase) was antagonized dose-dependently by RX781094. This agent was approximately 10-fold more potent than yohimbine. Radioligand binding studies also showed that RX781094 was more potent and selective than yohimbine at alpha 2-adrenergic sites. It is concluded that RX781094 is a potent and selective alpha 2-adrenergic antagonist.
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D004146:Dioxanes / Q000494:pharmacology*; D004147:Dioxins / Q000494:pharmacology*; D004837:Epinephrine / Q000037:antagonists & inhibitors; D019329:Idazoxan; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D014508:Urea / Q000096:biosynthesis; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D004147:Dioxins; D015016:Yohimbine; D014508:Urea; D000242:Cyclic AMP; D011224:Prazosin; D019329:Idazoxan; D004837:Epinephrine