Bhat S G, Nie Z, Ramkumar V
Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, USA.
Eur J Pharmacol. 1999 Oct 1;382(1):35-43. doi: 10.1016/s0014-2999(99)00584-1.
Reactive oxygen species contribute to male infertility by reducing sperm function. Our laboratory has recently demonstrated that reactive oxygen species stimulate the expression of adenosine A(1) receptor which confers cytoprotection in a variety of tissues. Since the adenosine A(1) receptor is highly expressed in the testis, the goal of this study was to determine whether this testicular adenosine A(1) receptor could also be regulated in vivo by reactive oxygen species. Cisplatin, a chemotherapeutic agent shown to alter testicular function, was used to generate reactive oxygen species in vivo. Testes obtained from Sprague-Dawley rats treated with cisplatin (8 mg kg(-1)) demonstrate increased lipid peroxidation and induction of heat shock protein by day 3. In addition, radioligand binding and Western blotting studies indicate an increase in testicular adenosine A(1) receptor in these rats. Scatchard analysis of [3H]8-cyclopentyl-1,3-dipropylxanthine (DPCPX) binding data indicates a significant increase in adenosine A(1) receptor number (B(max)) from 309+/-77 to 540+/-69 fmol mg(-1) protein in the cisplatin-treated group. The respective equilibrium dissociation constants (K(d)s) were 3.2+/-1.5 and 3.0+/-0.7 nM for the control and cisplatin-treated groups, respectively. Northern blotting analysis of rat testicular poly (A)(+) RNA indicates two adenosine A(1) receptor transcripts migrating at 3.4 and 5.6 kb, whose combined levels were increased by 49.3+/-9.3% following cisplatin treatment. These results indicate that cisplatin enhances adenosine A(1) receptor expression in the rat testis, possibly through promotion of oxidative stress.
活性氧通过降低精子功能导致男性不育。我们实验室最近证明，活性氧可刺激腺苷A(1)受体的表达，该受体在多种组织中具有细胞保护作用。由于腺苷A(1)受体在睾丸中高度表达，本研究的目的是确定这种睾丸腺苷A(1)受体在体内是否也受活性氧调节。顺铂是一种已被证明会改变睾丸功能的化疗药物，用于在体内产生活性氧。从接受顺铂（8 mg kg(-1)）治疗的Sprague-Dawley大鼠获得的睾丸在第3天显示脂质过氧化增加和热休克蛋白诱导。此外，放射性配体结合和蛋白质印迹研究表明这些大鼠睾丸中的腺苷A(1)受体增加。对[3H]8-环戊基-1,3-二丙基黄嘌呤（DPCPX）结合数据的Scatchard分析表明，顺铂治疗组的腺苷A(1)受体数量（B(max)）从309±77显著增加到540±69 fmol mg(-1)蛋白质。对照组和顺铂治疗组各自的平衡解离常数（K(d)s）分别为3.2±1.5和3.0±0.7 nM。对大鼠睾丸多聚（A）(+) RNA的Northern印迹分析表明，有两种腺苷A(1)受体转录本，迁移率分别为3.4和5.6 kb，顺铂处理后其综合水平增加了49.3±9.3%。这些结果表明，顺铂可能通过促进氧化应激增强大鼠睾丸中腺苷A(1)受体的表达。
