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Abstract: Effects of treatment with a single intra-peritoneal (i.p.) injection (0.84mgCd/kg body weight) of cadmium (Cd) on lipid/phospholipids profiles of rat brain microsomes and mitochondria were examined. At the end of one-week following treatment with Cd the microsomal total phospholipids (TPL) content was unchanged but the cholesterol (CHL) content increased. In one-month Cd-treated group both TPL and CHL contents increased. In one-week Cd-treated group the content of phosphatidylinositol (PI) decreased whereas that of lysophospholipid and phosphatidic acid (PA) increased. In one-month Cd-treated group the sphinghomyelin (SPM) and phosphatidycholine (PC) components increased whereas phosphatidyethanolamine (PE) and PA decreased. In mitochondria, CHL content increased in both Cd-treated groups. The content of TPL decreased only in one-month Cd-treated group. In one-week Cd-treated group the lysophospholipids increased whereas PI and phosphatidylserine (PS) decreased. In one-month group the lysophospholipids, PI and diphosphatidylglycerol (DPG) components decreased whereas PS and PE component increased. The results suggest that exposure to a single dose of Cd has differential and long-lasting effects on lipid/phospholipids profiles of rat brain microsomes and mitochondria. [Copyright &y& Elsevier]

Abstract: Studies on Cd hepatotoxicity have focused mainly on induction of cytochrome P450 system and related enzymes. In the present study young adult male rats given a single intra-peritoneal injection of Cd (0.84mg Cd/kg body weight) and effects on kinetic parameters rat liver microsomal Na+, K+-ATPase and G6Pase were evaluated at the end of 1 month and 1 week. The substrate and temperature kinetics parameters were examined and attempts were made to seek correlation with changes in lipid/phospholipid profiles. The Na+, K+ ATPase activity decreased only in 1 week Cd-treated group but recovered at the end of 1 month. The activity resolved in two distinct kinetic components in control as well as the experimental groups. In 1 week Cd-treated group the K m value of both the components was unchanged, whereas V max value decreased. In 1-month Cd-treated group V max value only of component I increased. The catalytic efficiency of both the components was not affected in the experimental groups. In 1-week Cd-treated group the energy of activations at high-temperature range (E H) and low-temperature range (E L) decreased, whereas for 1-month Cd-treated group the energies of activations did not change. The G6Pase activity measured at 37°C was high only in 1-month Cd-treated group. The activity resolved in two kinetically distinguishable components in control as well as in the experimental groups. K m value of component I decreased in both the Cd-treated groups. In 1-month Cd-treated group the V max value of component II increased. The catalytic efficiency of G6Pase was unchanged despite changes in K m and V max. In 1-week Cd-treated group the E H and E L decreased, whereas only E L showed decrease in 1-month Cd-treated group. Cholesterol (CHL) content increased in both the Cd-treated groups. Content of lysophospholipid (Lyso), spinghomyelin (SPM) and phosphatidic acid (PA) increased, whereas phosphatidylcholine (PC) and phosphatidylserine (PS) decreased in 1-week Cd-treated group. In 1-month Cd group the Lyso, SPM, and PC increased while PC, phosphatidylethanolamine (PE) and PA decreased. In conclusion, Cd has short-term effects on microsomal Na+, K+-ATPase which are reversed by the end of 1 month and that G6Pase does not seem to be a target of Cd insult. [Copyright &y& Elsevier]