TY - JOUR T1 - Blockade of Norepinephrine-Induced Lipolysis by Isomers of <em>dl</em>-1-(Nitrophenyl)-1-Hydroxy-2-Isopropylaminoethane JF - Molecular Pharmacology JO - Mol Pharmacol SP - 501 LP - 505 VL - 2 IS - 6 AU - JOHN J. LECH AU - PITAMBAR SOMANI AU - DEANE N. CALVERT Y1 - 1966/11/01 UR - http://molpharm.aspetjournals.org/content/2/6/501.abstract N2 - The ability of three new beta adrenergic blocking agents, dl-1-(2-nitrophenyl)-1-hydroxy-2-isopropylaminoethane (2-INPEA), dl-1-(3-nitrophenyl)-1-hydroxy-2-isopropylaminoethane (3-INPEA), and dl-1-(4-nitrophenyl)-1-hydroxy-2-isopropylaminoethane (4-INPEA) to antagonize norepinephrine-induced lipolysis was investigated utilizing an isolated fat cell preparation. All three isomers were capable of blocking norepinephrine competitively. The pA10 values for 2-INPEA, 3-INPEA, and 4-INPEA were determined and concentration-inhibition curves were plotted. 4-INPEA was found to be approximately ten times as potent as 2-INPEA and 3-INPEA, the latter two being equipotent. The results are discussed in relation to the classification of the adrenergic receptor in adipose tissue. ACKNOWLEDGMENT We wish to thank Mrs. Esther Nadolny for her technical assistance. This work was supported by USPHS grants HEO 7564 and AMO 7681. ER -