Abstract: Objective: To study the effects of etimicin (EM) and gentamicin (GM) on renal endoplasmic reticulum ⁴⁵Ca²⁺ uptake and Ca²⁺-Mg²⁺-ATPase activity. Methods: Using ⁴⁵Ca²⁺ incorporation technique and peacock blue spectrophotometry respectively. Results: EM and GM (≥3.4×10^-4 mol·L^-1) inhibited endoplasmic reticulum ⁴⁵Ca²⁺-uptake (the rate of inhibition: ≥17.4% and ≥25.5%, respectively); EM and GM (3.4×10^-2 mol·L^-1) inhibited Ca²⁺-Mg²⁺-ATPase activity (the rate of inhibition: 24.2% and 29.2%, respectively). Conclusion: At high concentration, EM and GM elevated intracellular calcium which may be related to their nephrotoxicity.

Key words: Etimicin (EM), Gentamicin (GM), Endoplasmic reticulum, 45Ca2+-uptake, Ca2+-Mg2+-ATPase