Mazon A F, Cerqueira C C C, Fernandes M N
Department of Physiological Sciences, Federal University of São Carlos, 13565-905 São Carlos, SP, Brazil.
Environ Res. 2002 Jan;88(1):52-63. doi: 10.1006/enrs.2001.4315.
The cellular changes in gill tissue induced by exposure to copper were studied in the tropical freshwater fish Prochilodus scrofa, with emphasis on chloride and pavement cells. Damage to gills included epithelial changes such as lifting, rupture, peeling of lamellar epithelium, lamellar fusion, hyperplasia, and cellular hypertrophy. Cell degeneration by necrosis and apoptosis was intense in fish exposed to 25 and 29 microg Cu L-1. Pavement cells showed microridge reduction on their surface. Chloride cells proliferated in the lamellar epithelia close to the onset of the lamellae. However, no changes in total chloride cell density in contact with the water were observed. The chloride cell apical area of fish exposed to copper increased, but only fish exposed to 25 microg Cu L-1 showed significant increase in the chloride cell fractional area. At this water copper concentration, almost 60% of the chloride cells were apoptotic. Necrotic chloride cells increased with copper in water, reaching 70% in fish exposed to 29 microg Cu L-1 (=LC50 calculated for this species). Pavement and chloride cell proliferation and hypertrophy on lamellar epithelia increased the thickness of the water-blood barrier. Our findings suggest severe impairment of ion regulation and gas transfer of fish exposed to copper.
研究了热带淡水鱼细须石脂鲤暴露于铜后鳃组织的细胞变化,重点关注氯化物细胞和扁平细胞。鳃的损伤包括上皮变化,如片状上皮的隆起、破裂、剥落、片状融合、增生和细胞肥大。在暴露于25和29微克/升铜的鱼中,坏死和凋亡引起的细胞变性很强烈。扁平细胞表面的微嵴减少。在鳃小片起始处附近的片状上皮中,氯化物细胞增殖。然而,未观察到与水接触的氯化物细胞总密度有变化。暴露于铜的鱼的氯化物细胞顶端面积增加,但只有暴露于25微克/升铜的鱼的氯化物细胞分数面积有显著增加。在此水铜浓度下,近60%的氯化物细胞发生凋亡。坏死的氯化物细胞随水中铜含量增加,在暴露于29微克/升铜(该物种计算出的半数致死浓度)的鱼中达到70%。片状上皮上扁平细胞和氯化物细胞的增殖及肥大增加了水-血屏障的厚度。我们的研究结果表明,暴露于铜的鱼的离子调节和气体交换严重受损。