The study aimed at evaluation the effect of dietary supplement of taurine on the oxidation-reduction status in riding horses, and especially on the extent of oxidative DNA degradation in lymphocytes.Ten Thoroughbred and half-bred geldings aged 6-13 years were classified according to breed and amount of work done into two groups – control (C, n=5) and experimental (E, n=5), the latter fed the diet with addition of 40 g taurine/horse/day. Blood samples were withdrawn from the horses’jugular vein before commencing the riding season and then after 30 days of working. In the blond some selected morphological and biochemical indicators were determined including the TBA-RS and 8-oxo-dG in lymphocyte DNA. It was found that physical effort of horses, being used for 30 days in recreation riding, affected homeostasis of redox status, and especially the rate of oxidative DNA degradation of lymphocytes. The addition of taurine to feed caused smaller oxidative stress,manifested by lower concentration of TBA-RS in plasma and of 8-oxo-dG in lymphocytes. The taurine lowered the lipid peroxidation intensity that occurred in horses due to the oxidative stress caused by physical effort. Furthermore, taurine revealed affinity to nucleic acids, counteracted the oxidative DNA degradation and decreased the damages of DNA in lymphocytes.
It has been reported that estrogen receptor-positive MCF-7 cells express TauT, a Na+-dependent taurine transporter. However, there is a paucity of information relating to the characteristics of taurine transport in this human breast cancer cell line. Therefore, we have examined the characteristics and regulation of taurine uptake by MCF-7 cells. Taurine uptake by MCF-7 cells showed an absolute dependence upon extracellular Na+. Although taurine uptake was reduced in Cl- free medium a significant portion of taurine uptake persisted in the presence of NO3 -. Taurine uptake by MCF-7 cells was inhibited by extracellular β-alanine but not by L-alanine or L-leucine. 17β-estadiol increased taurine uptake by MCF-7 cells: the Vmax of influx was increased without affecting the Km. The effect of 17β-estradiol on taurine uptake by MCF-7 cells was dependent upon the presence of extracellular Na+. In contrast, 17β-estradiol had no significant effect on the kinetic parameters of taurine uptake by estrogen receptor-negative MDA-MB-231 cells. It appears that estrogen regulates taurine uptake by MCF-7 cells via TauT. In addition, Na+-dependent taurine uptake may not be strictly dependent upon extracellular Cl-.
Zbadano wpływ sterylizacji na wartość odżywczą dwóch gatunków białka: mleka (kazeiny) i ryb (dorsza). Metodą chemiczną i biologiczną (strawność, przyswajalność i wydajność wzrostowa), określono poziom dostępnej metioniny i cysteiny w wątrobie i moczu zwierząt doświadczalnych.