The effect of plant and fish fat on the content of free and total malondialdehyde and vitamin E in livers of young and adult rats.

The MDA synthesis was investigated in male Wistar rats which were given various fats, such as soybean, fish, and evening primrose oils, as well as mixture of evening primrose and fish oils. Received results show that there is a clear correlation between the kind and quantity of PUFA present in the diet and possibilities of synthesis of free or protein bounded MDA. The animals' age was possitively correlated with these alterations.

[Balance of magnesium and iron and their content in tissues and body fluids of rats after supplementation with magnesium carbonate]. / Bilans magnezu i zelaza oraz ich zawartosc w narzadach i plynach ustrojowych szczurów poddanych suplementacji weglanem magnezu.

Effect of magnesium on iron and magnesium metabolism in rats were investigated. 96 male Wistar rats were divided into four groups received 2.5; 5.0 and 10.0 mg magnesium daily per kg of body weight--dissolved in 2%--solution of arabic gum (tests groups) or clear 2%--solution of arabic gum (test group) for 4 weeks and the next 4 weeks without supplements. Iron concentrations increased in the brain and kidney of the experimental rats, but decreased in the spleen, intestine and liver (2 and 4 weeks only) also in the heart and femur (only 8 week). Percentage of iron retention decreased during the whole experiment. Magnesium concentrations increased in the spleen, liver and intestine of rats. It was shown that at 8 weeks of experiment the magnesium level of heart and femur decreased (only groups received 2.5 mg and 5.0 mg Mg/kg b.w./24 h), but in group received 10.0 mg Mg/kg b.w./24 h increased for all experiment. The apparent retention of magnesium increased in start of the experiment. This results show that oral magnesium supplementation disturbs metabolism of these elements, especially balance of iron.

Effect of chlorfenvinphos, cypermethrin and their mixture on the intestinal transport of leucine and methionine.

We assessed the effect of 2-week oral treatment with chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 on the intestinal transport of L-leucine (Leu) and L-methionine (Met) in male Wistar rats. Both in vitro (jejunal slices) and in vivo (intestinal perfusion) methods were employed in the study, using Leu and Met labelled with 14C as markers of the investigated processes. Additionally, in the in vitro study, concentrations of two amino acids were measured in the whole blood, serum, liver and perfused segment of the intestine. In the in vitro study the kinetic constants describing the active and passive Leu and Met uptake were determined. The active uptake was found to be particularly affected by oral intoxication with chlorfenvinphos, cypermethrin and their mixture. This susceptibility was seen as major alterations in the parameters of active uptake, i.e. Jm and Ki constants in the pesticide-exposed groups as compared to controls. In the in vivo study we found a decreased rate of Leu and Met disappearance from the intestinal lumen, decreased blood concentrations of Leu and Met and decreased liver content of Leu in the pesticide-exposed groups as compared to controls. The findings allow the conclusion that oral administration of chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 impairs the intestinal transport of Leu and Met and alters their distribution in the rodent body.

The study of leucine and methionine transport in the gut of rats intoxicated with thiram.

The effects of thiram on amino acids transport in rats jejunum were investigated. Using the gut everted sac method it was shown that 4 weeks intoxication with the pesticide (5% DL50 per os daily) caused time dependent inhibition in transport of C14-leucine and C14-methionine in the rat jejunum. In order to obtain further information, the influx of both amino acids into the jejunum slices was investigated in rats treated with thiram for 2 weeks. Over a range of amino acid concentrations (0-20 mM) the influx of these compounds was defined as the sum of a saturable term (active transport) and a linear term (passive transport). It was shown that thiram affected only the active transport of amino acids. The analysis of this transport for leucine using Lineweaver-Burk plots showed a decrease of the half-saturation constant (Kt), while the maximal value (Jm) remained unchanged. In the methionine transport study both kinetic constants were changed.

[Study of combined effects of mixtures of pesticides from various chemical groups on calcium absorption in the rat intestine. I. Dichlorvos and thiram]. / Badanie skojarzonego dzialania mieszanin pestycydów z róznych grup chemicznych na wchlanianie wapnia w jelicie szczura CZ. I. Dichlorfos i tiuram.

Investigation was made of the effect of many-times repeated treatment with single pesticides: tiuram and dichlorfos (administered in a daily dose corresponding to 5% of LD50), and with their mixture, on calcium uptake by rat duodenum sections. Calcium uptake was examined by the method of Papworth and Patrick, as modified by the present authors. The amount of calcium transported by the sections was determined by the liquid scintillation method. Total transport was expressed in microM Ca2+/g tissue/h; subsequently, the participation of active and passive transport in total transport was determined. It was shown that administration of DDVP to rats during 14 days caused disturbances in active absorption of calcium, manifesting themselves by a significant decrease in the constant Jm (maximal transport rate) and in the constant Kt, this pointing to a rise of calcium affinity to the carrier. The effect of DDVP on passive transport was only slight. Under the same experimental conditions tiuram exerted an effect on both active and passive calcium transport. It caused a drop in the constant Jm and Kt (active transport), and to inhibition of passive transport. According to statistical treatment of the results, the effect of both pesticides combined on active transport does not differ from the effect of DDVP itself. Thus, the differences in diffusion probably result from the action of tiuram.

[Micromethod of determining the caloric value of food using chromic acid]. / Mikrometoda oznaczania wartosci energetycznej zywnosci z uzyciem kwasu chromowego.

Rozental's method using chromic acid for the determination of the caloric value of meals has failed to find practical application, on account of applying faulty amounts of the oxidizing reagents and of the tested sample, as well as large volumes of liquids and reaction solutions. In this connection, we thoroughly verified this method, introducing another value of the correction coefficient. By changing the proportions of the reaction components, we developed a modified method referred to as micromethod for caloric value determination using chromic acid. Application of minimal amounts of reagents and tested sample allowed for analysing food samples with caloric value up to 200 kcal/100 g as well as for cutting down the duration of the analysis.

[Studies on the combined effect of pesticide mixtures belonging to different chemical groups on calcium absorption in rat intestine. Part II. Chlorfenvinphos and cypermethrin]. / Badanie skojarzonego dzialania mieszanin pestycydów z róznych grup chemicznych na wchlanianie wapnia w jelicie szczura. Czesc II. Chlorfenwinfos i cypermetryna.

In male Wistar rats study was made of the effect of multiple treatment (14 days) with single pesticides (chlorfenvinphos and cypermethrin) and with their mixture on intestinal calcium absorption. Pesticides were administered intragastrically through a stomach tube in a daily dose corresponding to 5% of LD50; in the case of the pesticide mixture, 5% of LD50 of each component were administered. Calcium uptake (active and passive) by duodenal sections were determined by the method of Papworth and Patrick, modified by the present authors. It was found that under the applied experimental conditions chlorfenvinphos influences the active transport of calcium, causing an increase in the values of the constants Jm (maximal transport rate) and Kt (affinity of calcium to carrier), whereas it inhibits the passive transport. Similar changes were displayed by rats exposed to cypermethrin. On the other hand, combined administration of both pesticides led to a lack of changes in the efficiency of active transport and to impairment of passive transport, as compared with control.

The effect of zinc and magnesium on calcium uptake into the rat duodenum slices.

The experiments were carried out on 80 male Wistar rats, divided into four groups as follows: group 1, treated orally with ZnCl2 at a dose of 10 mg Zn2+/kg for 14 days; group 2, control; group 3, MgCl2-treated at a dose of 5 mg Mg2+/kg; group 4, treated with ZnCl2 plus MgCl2 in the same manner as groups 1 and 3. The influx of calcium into the rat duodenum slices was investigated in vitro by the method of Papworth and Patrick. Over a range of calcium concentrations (0-10 mM) the influx of this element was defined as a sum of a saturable term (active transport) and a linear term dependent on concentration (passive transport). In the zinc-treated rats only the saturable term was affected. The study of this term by Lineweaver-Burk plots showed a decrease of the half-saturation constant, Kt, while the maximal value, Jm, remained unchanged. Moreover, magnesium was shown to interact with zinc at gut level because simultaneous oral administration of Mg2+ and Zn2+ to rats protected them against the inhibition of calcium uptake observed when Zn2+ was given alone.

The influence of furfural inhalation poisoning on calcium and phosphorus metabolism in rats.

The inhalation of furfural, 20 mg/m3 by adult rats during 3 months for 5 h daily, 6 times a week, did not change the calcium and phosphorus level in blood serum and in bones, but depressed the activity of alkaline phosphatase in blood serum. The exposure to furfural of immature rats (6-7 weeks old) during 4 weeks caused a depression of blood serum and intestine mucosa alkaline phosphatase activity, elevation of calcium and phosphorus levels in blood serum with concomitant fall in bones, and a decrease in calcium excretion with urine.