Comparative acute toxicity of gallium(III), antimony(III), indium(III), cadmium(II), and copper(II) on freshwater swamp shrimp (Macrobrachium nipponense)

BACKGROUND: Acute toxicity testing were carried out the freshwater swamp shrimp, Macrobrachium nipponense, as the model animal for the semiconductor applied metals (gallium, antimony, indium, cadmium, and copper) to evaluate if the species is an suitable experimental animal of pollution in aquatic ecosystem. RESULTS: The static renewal test method of acute lethal concentrations determination was used, and water temperature was maintained at 24.0 ± 0.5°C. Data of individual metal obtained from acute toxicity tests were determined using probit analysis method. The median lethal concentration (96-h LC50) of gallium, antimony, indium, cadmium, and copper for M. nipponense were estimated as 2.7742, 1.9626, 6.8938, 0.0539, and 0.0313 mg/L, respectively. CONCLUSIONS: Comparing the toxicity tolerance of M. nipponense with other species which exposed to these metals, it is obviously that the M. nipponense is more sensitive than that of various other aquatic animals.

vitro effect of lead, silver, tin, mercury, indium and bismuth on human sperm creatine kinase activity: a presumable mechanism for men infertility

The aim of the present study was to investigate the in vitro effects of mercury [Hg[+2], lead [Pb[+2]], silver [Ag[+2]], tin [Sn[+2]], bismuth [Bi[+3]] and indium [In[+3] ions on sperm creatine kinase. creatine kinase was isolated from human sperm homogenates after chromatography on a DEAE cellulose column. At 60 microg ml[-1] metal concentration, 70% of the creatine kinase activity was inhibited by Hg[+2], while at the same concentration, Pb[+2], Ag[+2], Sn[+2], Bi[+3] and In[+3] caused 68%, 66.5%, 65.7%, 64.7% and 62.7% inhibition, respectively. All six metal ions displayed a competitive type of inhibition mechanism for the isolated creatine kinase as analyzed by Lineweaver-Burk plot. KA values of Hg[+2], Pb[+2], Ag[+2], Sn[+2], Bi[+3] and In[+3] were calculated and 8.34 mM, 5 mM, 4.54 mM, 3.45 mM, 3.12 mM and 2.63 mM values were obtained, respectively. All the studied metal ions, at levels of 60 micro g ml[-1], may reduce normal sperm metabolism by inhibition of sperm creatine kinase, which probably is an important cause of infertility in men. However, further investigations, as in vitro and in vivo, are needed to elucidate the exact mechanism of heavy metals on male reproductive functioning at the molecular level