Zinc binding to the gills of rainbow trout: the effect of long‐term exposure to sublethal zinc

摘要: The effects of sublethal waterborne Zn (2·28 μmol l−1) on binding kinetics to the apical gill surface were studied in juvenile rainbow trout (Oncorhynchus mykiss). Two separate radiotracer techniques employed ascertain this information. First, vitro kinetic experiments performed at extremely elevated zinc concentrations (up 20 mmol measure relatively low-affinity sites epithelium. There no differences parameters (Km and Bmax) for fish sublethally exposed 21 days their simultaneous controls. Nevertheless, Ca did have an increased inhibitory effect Zn-exposed suggesting that anionic groups epithelium these had been altered some manner. Additionally, vivo investigated using environmentally relevant (low l−1 range) isolate high-affinity (Ca transporters). No appreciable alterations Km Bmax values seen between group its control following 15 exposure. Furthermore, significant CC morphometry observed treatments. Despite lack treatment effects, there temporal Km, fractional area both groups. It is proposed fluctuations are controlled by hormonal factors (such as stanniocalcin), believed play a role influx.