Binding Studies of Cardiovascular Drug on β Adrenoceptors in Rat Left Ventricle using (-)-[^3H]-DHA, Non-β_1/β_2-selective Radioligand = β_1/β_2 비선택적 Radioligand (-)-[^3H]-DHA를 사용한 Rat 좌심실 β-adrenoceptor에 대한 심장순환계 약물의 Binding

다국어 초록 (Multilingual Abstract)

β-Adrenoceptor binding study of β-agonist ((-)NE), β-antagonists ((±)propanolol, labetalol) and PDE inhibitors (imazodan, KR-30045, KR-30075 etc.) was performed using(-)-[^3H]-DHA, as a non-β_1/β_2 selective radioligand. In saunation studies, K_α B_max of(-)-[^3H]-DHA to β-adrenoceptors in rat left ventricle in which both β_1 and β_2 receptors coexist were determined to be 1.5±0.43 nM and 22.0土0.9 fmol/㎎ protein, respectively. (±)Propranolol, labetalol and(-)NE competed for(-)-[^3H]-DHA binding sites in an essentialy monophasic manner with Ki=l7.0±0.40 nM, 57.3±l.30 nM and 1.57±0.95 μM, respectively. All of PDE inhibitors inhibited the(-)-[^3H]-DHA binding by only below l0% even at the high concentration of l0 ^3M. The present results suggest that propranolol, labetalol and NE are non-β_1/β_2 selective antagonists and agonist, respectively.
Additionally, this study shows that imazodan and new synthesized PDE inhibitors may hardly have the affinities to β-adrenocetors in cardiac muscle.