Effects of hemazin SC 500 (terbuthylazine) on antioxidative enzymes in human erythrocytes in vitro

The aim of this work was to investigate the effect of the commercial formulation hemazin SC 500, an herbicide containing terbuthylazine as the active compound, on the isoenzyme patterns and activities of Cu-Zn superoxide dismutase (SOD1) and catalase (CAT), as well as on the glutathione S-transferase (GST) activity, in human erythrocytes in vitro. The human erythrocytes were treated with hemazin SC 500 over a broad range of terbuthylazine concentrations (37 nmol L-1? ?37 ?mol L-1) for 1 and 3 h at a temperature of 37?C. Native electrophoresis of the control and treated samples revealed two SOD1 and one CAT isoform. Treatment did not affect the SOD1 and CAT isoenzyme profile, but induced a change in their activities. Terbuthylazine at lower concentration induced a significant increase of the total SOD1 activity and decreased the GST activity in samples incubated for 1 and 3 h. On the other hand, the highest increase in the CAT activity was observed for the sample treated for 1 h with a higher concentration of terbuthylazine. Hemazin SC 500 containing terbuthylazine induces changes in the erythrocyte antioxidative system whereby the response of individual enzymatic antioxidants depends on the concentration of the pesticide and the incubation time.

Activity of Acid Phosphatases in Ectomycorrhizal Fungi

<p>The colonization of plant roots by mycorrhizal fungi, generally increases P content in the host plant when in soils with low levels of P. The objective of this work was to evaluate the activity of acid phosphatases in two isolates of <em>Pisolithus microcarpus</em>, grown in different sources and concentrations of phosphate and to characterize the phosphatase isoenzymes produced by isolates. Both isolates were grown on Melin-Norkrans modified (MNM) medium enriched with organic (Po) or inorganic (Pi) sources of phosphorus, at five different concentrations, in order to study the activity of mycelial surface acid phosphatases during incubation for up to 96 h. Activity of acid phosphatases increased when the fungi were grown without or at low concentrations of Pi. Intraspecific differences were observed between the isolates with regard to acid phosphatase production. A greater decrease in phosphatase activity was observed when incubation time was increased than when Pi concentration was increased. At an incubation time of 96 h, activity of acid phosphatases in isolate 90A increased with increasing Po concentration, while for isolate RV82 remained constant over the different incubation periods and Po concentrations tested. When grown in media without Pi, an additional band appeared in the isoenzyme pattern of RV82, while isoenzyme production was not altered in isolate 90A when grown in media without Pi or with 2 mM Pi, showing differences in their isoenzyme patterns. Isolate 90A possesses a potential competitive advantage when utilized in mycorrhizal association with <em>Eucalyptus </em>because of its ability to utilize Po.</p>

Isoenzyme pattern of glutamate dehydrogenase as a reflection of nitrogen metabolism in Lupinus albus

Glutamate dehydrogenase (L-glutamate: NAD dehydrogenase, EC 1.4. 1.2; GDH) activity and electrophoretic separation pattern of the enzyme were studied. The enzyme was extracted from embryos of <i>Lupinus albus</i> decotyledonized and cultured for 24, 48 and 72 hours in media containing various combinations of saccharose, ammonium chloride, nitrate as well as amino acids: glutamate, aspartate, glutamine and asparagine. The absence of sugar in the medium resulted in an increase of specific activity of GDH, measured by the rate of NADH + H⁺ oxidation, and induced formation of new isoenzymes of NAD⁺ - dependent GDH. Most significant increase in GDH specific activity and most evident appearance of new isoenzymes in the embryos were noted when sugar was substituted in the medium by any of the mentioned amino acids. Induction of new isoenzymes could also be seen when ammonium salts were pre-sent in the medium. GHD isoenzymatic patterns were obtained in various trophic conditions. It is suggested that the GDH isoenzyme patterns may serve as a nitrogen metabolism index of a tissue from which the enzyme has been extracted.

How the sialylation level of serum N-acetyl-β-D-glucosaminidase a form in type 1 diabetes mellitus influences its activity?

It has been verified that serum N-acetyl-?-D-glucosaminidase (NAG) activity is elevated in diabetes, but there are no reports about changes of the sialic acid (SA) content in the carbohydrate parts of NAG A form and its influence on total NAG activity changes in type 1 diabetes mellitus patients without and with secondary complications. NAG A forms were isolated, purified and characterized from the serum of 81 IDDM patients with and without secondary complications (retinopathy, polyneuropathy and nephropathy) and 25 healthy persons. The content of ?-2,6-bound SA and isoenzyme patterns of purified A form, total NAG and A form activities were determined. In all diabetic groups, A form sialylation levels were 2-3.5 times lower compared to control, while their acidities (fractions with pI 4.25-5.1) increased, particularly with progression of secondary complications. Total serum NAG activities and percentages of A form were significantly higher (P<0.001) in all diabetic groups and negatively correlated with the ?-2,6-bound SA content of the A form. In addition, they decreased as secondary diabetic complications became more complex. Observed changes could be the consequence of structural changes in the A form due to significant increase in its acidity, i.e. negative charge which originate from groups other than SA.