Yoo J L, Janz D M
Department of Zoology, Oklahoma State University, 430 Life Sciences West, Stillwater, Oklahoma 74078, USA.
Arch Environ Contam Toxicol. 2003 Jul;45(1):110-20. doi: 10.1007/s00244-002-0109-7.
The 70-kDa stress protein family (HSP70) plays important roles in a variety of physiological processes, including protein chaperoning, protection against apoptosis, steroidogenesis, and general cellular stress responses in vertebrate organisms, and has also been proposed as a biochemical marker of environmental stress, such as toxicant exposure. The objectives of this study were to determine HSP70 protein expression in head kidney, liver, gill, and ovarian tissues and to examine reproductive physiological responses in female fishes exposed chronically to sublethal metal concentrations. Female black bullhead (Ameiurus melas) and bluegill sunfish (Lepomis macrochirus) were collected from Tar Creek, Oklahoma (flowing through the Tri-State mining district) and from a nearby reference creek (Lytle Creek) during spring (prespawning; 26.5 +/- 0.95 degrees C water temperature) and winter (ovarian recrudescence; 4.8 +/- 0.80 degrees C water temperature). Aqueous (dissolved and suspended) concentrations of Cd and Zn and liver concentrations of Cd and Zn in both fish species were significantly greater at Tar Creek compared to Lytle Creek. HSP70 expression was consistently elevated in the head kidney of both fish species collected at Tar Creek in comparison to fish collected from the reference creek. In contrast, no consistent differences were observed in HSP70 expression in liver, gill, or ovarian tissues between sites. Significant seasonal differences were observed in expression of HSP70 in gill tissue of both species, in ovarian and liver tissue of bluegill sunfish and in head kidney of black bullhead. Serum testosterone concentration was significantly reduced in sunfish collected from Tar Creek during winter. Gonadosomatic and hepatosomatic indices were significantly lower in black bullhead collected from Tar Creek during spring, and condition factors were lower in black bullhead collected from Tar Creek during both spring and winter. There was no significant difference in the extent of ovarian follicular cell apoptosis in either species collected during spring. In conclusion, we observed significant tissue specific differences and seasonal variation in expression of HSP70, as well as alterations in circulating testosterone levels in female fish chronically exposed to metals.
70 kDa应激蛋白家族（HSP70）在多种生理过程中发挥重要作用，包括蛋白质伴侣作用、抗细胞凋亡保护、类固醇生成以及脊椎动物机体的一般细胞应激反应，并且还被提议作为环境应激（如接触毒物）的生化标志物。本研究的目的是确定HSP70蛋白在黑头肾、肝脏、鳃和卵巢组织中的表达，并检查长期暴露于亚致死金属浓度的雌性鱼类的生殖生理反应。在春季（产卵前；水温26.5±0.95℃）和冬季（卵巢再发育；水温4.8±0.80℃）从俄克拉荷马州的塔尔溪（流经三州矿区）和附近的参考溪流（利特尔溪）采集雌性黑牛头鲇（Ameiurus melas）和蓝鳃太阳鱼（Lepomis macrochirus）。与利特尔溪相比，塔尔溪中两种鱼类的水相（溶解态和悬浮态）镉和锌浓度以及肝脏镉和锌浓度均显著更高。与从参考溪流采集的鱼类相比，在塔尔溪采集的两种鱼类的黑头肾中HSP70表达持续升高。相比之下，不同地点之间肝脏、鳃或卵巢组织中HSP70表达未观察到一致差异。在两种鱼类的鳃组织、蓝鳃太阳鱼的卵巢和肝脏组织以及黑牛头鲇的黑头肾中，观察到HSP70表达存在显著的季节性差异。冬季从塔尔溪采集的太阳鱼血清睾酮浓度显著降低。春季从塔尔溪采集的黑牛头鲇的性腺体指数和肝脏体指数显著更低，并且春季和冬季从塔尔溪采集的黑牛头鲇的状况因子均更低。春季采集的两种鱼类中卵巢卵泡细胞凋亡程度均无显著差异。总之，我们观察到长期暴露于金属的雌性鱼类中HSP70表达存在显著的组织特异性差异和季节性变化，以及循环睾酮水平的改变。
