Consequences of long-term selenium-deficient diet on the prostacyclin and thromboxane release from rat aorta.

It is known that peroxides, which are increased during Se deficiency because of reduced glutathione peroxidase (GSH-Px) activity, can influence the prostacyclin I2/thromboxane A2 (PGI2/TXA2) ratio. In this study we analyzed the PGI2 and TXA2 formation of aortas of long-term Se-deficient rats. Despite low GSH-Px activity in the Se-deficient group, the basal PGI2 and TXA2 formation was not different versus control animals (PGI2: 2295+/-1134 pg/mg vs 2940+/-1134 pg/mg; TXA2: 3.83+/-1.06 pg/mg vs 5.67+/-2.99 pg/mg). However, we checked the capacity of the aortas of Se-deficient rats to compensate for a suddenly increased peroxide concentration. After peroxide stimulation, the PGI2 release was significantly lower in the Se-deficient group compared to the control group (PGI2: 3507+/-1829 pg/mg vs 7986+/-2636 pg/mg). Again, the TXA2 release did not show any differences. The release ratio of PGI2/TXA2 decreased under peroxide stress in Se-deficient animals. Although long-term Se deficiency showed a relatively well-balanced metabolism under resting conditions, sudden stress, accompanied by an excessive radical production, cannot be compensated.

Targeting dipeptidyl peptidase IV (CD26) suppresses autoimmune encephalomyelitis and up-regulates TGF-beta 1 secretion in vivo.

CD26 or dipeptidyl peptidase IV (DP IV) is expressed on various cell types, including T cells. Although T cells can receive activating signals via CD26, the physiological role of CD26/DP IV is largely unknown. We used the reversible DP IV inhibitor Lys[Z(NO(2))]-pyrrolidide (I40) to dissect the role of DP IV in experimental autoimmune encephalomyelitis (EAE) and to explore the therapeutic potential of DP IV inhibition for autoimmunity. I40 administration in vivo decreased and delayed clinical and neuropathological signs of adoptive transfer EAE. I40 blocked DP IV activity in vivo and increased the secretion of the immunosuppressive cytokine TGF-beta1 in spinal cord tissue and plasma during acute EAE. In vitro, while suppressing autoreactive T cell proliferation and TNF-alpha production, I40 consistently up-regulated TGF-beta1 secretion. A neutralizing anti-TGF-beta1 Ab blocked the inhibitory effect of I40 on T cell proliferation to myelin Ag. DP IV inhibition in vivo was not generally immunosuppressive, neither eliminating encephalitogenic T cells nor inhibiting T cell priming. These data suggest that DP IV inhibition represents a novel and specific therapeutic approach protecting from autoimmune disease by a mechanism that includes an active TGF-beta1-mediated antiinflammatory effect at the site of pathology.

[Occurrence and use of anthracenones]. / Niektoré aspekty výskytu a vyuzitia antracenónov.

The present paper aims to inform the pharmaceutical public about anthracenons and their natural producers. The first available mention dates from 1888 and the present authors also describe their synthesis and use in clinical practice.

[Curcumin as a potential antioxidant]. / Kurkumín ako potenciálne antioxidans.

Curcuma vera is one of the medicinal plants of traditional Chinese medicine. The plant is the natural source of one of natural antioxidative agents--curcumin. The present paper summarizes information about the properties of curcumin and presents the characteristics of Curcuma vera, its producer.

Invertase in immobilized cells of Papaver somniferum L.

Papaver somniferum L., (opium poppy) cells were after permeabilization in Tween 80 immobilized by glutaraldehyde without any carrier. Cells immobilized by cross-linking performed the hydrolysis of sucrose. The immobilized cells were characterized by high invertase activity and appropriate physico-mechanical properties.