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41.
The fraction of free fatty acids (FFA) is present in skeletal muscles. However, there is almost no data regarding regulation in the content of this intramuscular lipid pool. We took advantage of the isolated muscle preparation to examine whether: a) increasing exogenous concentration of FFA (500microM or 700microM, 30min) b) insulin (10.00 I.U./L, 30min), c) adrenalin (4.4 nM, 30 min), or d) contractions (200ms, tetani, 1Hz, 30min), affect the FFA content inside myocytes. Incubation of soleus (S) and extensor digitorum longus (EDL) with increasing concentrations of exogenous FFA (from 500microM to 700microM) resulted in an increase in the total FFA fraction in both muscles studied (by 280.2% and 259.1%, respectively). In contracting muscles FFA pool was significantly reduced both in S (by 73.1%) and in EDL (by 31.1%). Neither stimulation by adrenalin nor insulin affected the total content of FFA fraction in the muscles examined. We conclude that a) increased availability of exogenous FFA at the sarcolemma level results in an increase in the size of intramuscular FFA fraction b) the intracellular FFA fraction is utilized by contracting muscles with regard to the fiber composition and to a greater extent in more oxidative muscles, c) FFA fraction remains stable upon stimulation by insulin or adrenalin. 相似文献
42.
The course of acute infection of mice with ts mutant or the native strain DNA and the antigens of HSV in brain nerve cells were determined. Virus DNA was detected in brains of all mice in both animal groups while the virus antigens--only in cells of mice infected with the native strain. It can be suggested, therefore, that the ability of ts mutant to replicate in central nervous system of the infected mice is lacking or much lower. The detection of virus nucleic acid 3-5 months after virus infection might indicate a possibility of establishing latent infection. However, ts mutant showed a significantly lower possibility of latency induction, as compared with highly virulent strains. It was found that the mutant ability to induce latent infection was markedly increased when mice were treated with both ts mutant and Depo-Medrol as immunosuppressive agent. This finding shows both a possibility of increase of frequency of latent infections in the state of immunosuppression, and of activation of the latent infection (recurrence of acute form of infection). 相似文献
43.
The study was undertaken to investigate the ability of enterococci to assimilate iron via siderophores of bacteria living in the same habitats in the human organism. The potential recipients of exogenous siderophores were six Enterococcus faecalis and six Enterococcus faecium strains, isolated from clinical materials of human origin. The donors of siderophores were Gram-negative rods (various species of the Enterobacteriaceae, Pseudomonas and Acinetobacter) and Gram-positive cocci (various species of Staphylococcus and Streptococcus). All of the investigated E. faecium and only two E. faecalis strains demonstrated the ability to utilize the siderophores of the aforementioned bacterial groups, predominantly the chelators of Gram-negative rods, those of Gram-positive cocci were utilized to a smaller extent. Four recipient strains from E. faecalis species did not demonstrate the ability to utilize siderophores synthesized by all of 40 investigated donor strains. 相似文献
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The effect of long-term diets enriched with natural antioxidants was studied on Wistar rats with average initial body weight 150 g. After enrichment of the diet with selenium (0.1 ppm of sodium selenite per 100 g of diet), with vitamin E (6 mg of alpha-tocopherol per 100 g of diet) and selenium and vitamin E together the following results were obtained: diets enriched with selenium or vitamin E given for 12 months reduced the production of lipid peroxides in the liver and serum of the rats. On the other hand, addition of both antioxidants to the diet had no effect on lipid peroxide levels in the animals. Diet enrichment for 12 and 18 months with selenium or vitamin E had no effect on the levels of total cholesterol and HDL cholesterol. The obtained results suggest that selenium and alpha-tocopherol exert an inhibitory action on the processes of ageing in the experimental animal model. 相似文献
48.
W Niewiarowski Z J Le?nikowski A Wilk P Guga A Okruszek B Uznański W Stec 《Acta biochimica Polonica》1987,34(2):217-231
Diastereomers of the title compound were obtained and absolute configuration was assigned by means of stereochemical correlation. Their reaction with 3'-O-methoxyacetylthymidine in the presence of triisopropylbenzenesulphonyl (4-nitro) triazole is neither chemo- nor stereo-selective and leads to diastereomeric pairs of dithymidyl (3',5')methanephosphonate and -methanephosphonothioate. Obtained results are discussed in terms of mechanism of activation of phosphodiesters under conditions known as "phosphotriester approach to oligonucleotide synthesis". 相似文献
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Summary The pattern of the vascular supply to the choroid of the frog eye was studied in toto with the use of the injection-replication-SEM technique. The choroid of anuran amphibians is composed mainly of the choriocapillaris. In both species studied (Rana temporaria, Rana esculenta), an independent arterial supply to the choriocapillaris supplemented that from the ciliary arteries. This additional vascular route arises from the optic artery, a separate branch of the arteria infundibularis superficialis. The optic artery, accompanied by its vein within the vascular sheath of the optic nerve, joins the rich arterial capillary network of the choriocapillaris and supplies the posterior pole of the ocular bulb. The superficial capillary network displays a dense collar around the entrance of the optic nerve into the eye and is composed of a circular meshwork of small capillaries, several layers deep. More peripherally, however, it becomes single layered. This capillary network, as a whole, establishes numerous connections with the adjacent choriocapillaris at the posterior pole of the ocular bulb. In anuran amphibians the complex arrangement of both arterial systems supporting the choriocapillaris may be regarded as a more complete equivalent of the short posterior ciliary arteries of mammals. 相似文献