[ effect of titanium on stearic acid transport in rat everted gut sac]

Background and Objective: an everted intestinal sac [EGS] technique has been used to extensively estimate the transport and intestinal absorption in rats. Therefore, a number of factors such as pH and the nature of solvent may play an important role in fatty acid uptake by enterocytes. There are reports indicating that fatty acid transport is affected by many biochemical parameters including trace elements. In this study the effect of titanium on stearic acid transport was investigated

Materials and Methods: wistar male rats [200-250gr] were used for the experiments. Rats were killed, their intestine was removed and the jejunum parts were dissected. Everted gut sac was prepared from these parts. Sacs full of buffer were incubated in a medium containing stearic acid and titanium. Then the transported stearic acid inside the EGS was measured by spectrophotometer under different conditions of temperature and concentrations. Data was analyzed using SPSS software and Mann Whitney test

Results: the results showed that titanium decreased fatty acid uptake by enterocytes in a dose dependent manner. Titanium concentrations of 0.5, 1, 1.5 and 10 micromoles in the presence of sodium chloride can decrease the uptake of stearic acid by 32.2%, 43.4%, 54.5% and 61.5%, respectively. Titanium concentrations of 0.5, 1, 1.5 and 10 micromoles in the absence of sodium chloride in medium could decrease the stearic acid by 10%, 19.5%, 23.9% and 28.3% respectively which is not very affective

Conclusion: stearic acid transport appeared to be a Na dependent process and titanium may exert its inhibitory effect by interfering with this system. Our results showed that the incubation time, stearic acid concentration and pH were effective on stearic acid transport. Titanium decreased stearic acid transport in Rat EGS. This should be considered seriously, especially in people exposed to titanium compounds for a long period

effect of aluminum on biochemical parameters related to bone metabolism: a model study of hemodialysis patients

The influence of aluminum on some serum parameters related to bone metabolism has been investigated by daily administration of aluminum over different periods of time. Daily administration of aluminum [1 mg/kg BW] for 20 or 50 days elevated serum phosphorous concentration by 16 percent and had no significant effect on serum calcium level. When aluminum was injected as a complex with citric acid [1:1] there was a 22 percent elevation in serum phosphorous concentration, but again had no significant effect on serum calcium. Same amounts of aluminum caused a 28 percent elevation in serum alkaline phosphatase [ALKP], but had no significant effect on serum parathormone [PTH] either with or without citric acid. A marked reduction [about 41 percent] in serum calcitonin was observed when rats were given aluminum with or without citric acid. The relationship between aluminum toxicity and osteomalacia has been discussed

Chromium interaction with iron metabolism in rat: a model study in relation to hemodialysis patients

The interaction between chromium and some serum iron related parameters were investigated. Intraperitoneal administration of 1 mg/kg chromium [as chromium chloride] for 45 days reduced the serum iron and total iron binding capacity by 27% and 11% respectively. Ferritin and hemoglobin concentrations were also reduced by 22% and 18%, respectively. The results suggest that chromium influences iron metabolism and these two elements are biochemically interrelated