Camins A, Jimenez A, Sureda F X, Pallàs M, Escubedo E, Camarasa J
Laboratory of Pharmacology and Pharmacognosy, Faculty of Pharmacy, University of Barcelona, Spain.
Life Sci. 1996;58(9):753-9. doi: 10.1016/0024-3205(95)02353-4.
The presence of [3H] NBMPR binding sites in the mitochondrial fraction of rat testis is described. The dissociation constant (KD) from saturation studies was 0.16 +/- 0.04 nM. The association and dissociation rate constants (k1 and k-1) were 3.95 +/- 0.57 x 10(8) M(-1) min(-1) and 0.025 +/- 0.002 min(-1), respectively. The number of binding sites was 2,100 +/- 163 fmols/mg protein. [3H] NBMPR binding was inhibited, in a nanomolar range, by NBMPR (KI= 0.23 +/- 0.02 nM), OH-NBMPR (KI= 2.30 +/- 0.55 nM) and HNBTG (KI= 2.58 +/- 0.33 nM). In the micromolar range, adenosine receptor ligands such as PIA (3.46 +/- 1.36 microM), 2-chloroadenosine (18.81 +/- 3.36 microM) and NECA (8.26 +/- 3.90 microM), and mitochondrial benzodiazepine receptor ligands such as Ro 5-4864 (5.15 +/- 1.82 micrmoM and PK 11195 inhibited the specific binding of [3H] NBMPR. These results suggest the existence of a nucleoside transport system in the mitochondrial fraction of rat testis.
本文描述了大鼠睾丸线粒体部分中[3H] NBMPR结合位点的存在情况。饱和研究得出的解离常数（KD）为0.16±0.04 nM。结合和解离速率常数（k1和k-1）分别为3.95±0.57 x 10(8) M(-1) min(-1)和0.025±0.002 min(-1)。结合位点数量为2,100±163 fmols/mg蛋白质。[3H] NBMPR的结合在纳摩尔范围内受到NBMPR（KI = 0.23±0.02 nM）、OH-NBMPR（KI = 2.30±0.55 nM）和HNBTG（KI = 2.58±0.33 nM）的抑制。在微摩尔范围内，腺苷受体配体如PIA（3.46±1.36 microM）、2-氯腺苷（18.81±3.36 microM）和NECA（8.26±3.90 microM），以及线粒体苯二氮䓬受体配体如Ro 5-4864（5.15±1.82 micrmoM）和PK 11195抑制了[3H] NBMPR的特异性结合。这些结果表明大鼠睾丸线粒体部分存在核苷转运系统。
