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Aminoglutethimide, a corticosteroid inhibitor, administered at a daily dose of 150 mg per kg body weight, showed a dramatic interference with ovarian histology in the rat. The drug caused thinning of the germinal epithelium and disruption of the layers of the follicular cells. It also resulted in the appearance of cytoplasmic vacuoles and distortion of follicle cell nuclei. In the corpus luteum, it caused shrinkage of the lutein cells, resulting in large spaces between the cords of cells. It also arrested immature follicles at various stages of their development. Our results indicate that aminoglutethimide, by modifying ovarian structure in the rat, interferes with the ovulation process. 相似文献
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The objective of this study was to examine the effect of oxLDL on prostacyclin (PGI2) generation by rat aortic segments and to see whether the lipid fraction of oxLDL or its components are responsible for that effect. We also tested if antioxidants have any protective role. LDL oxidized by copper was characterized by higher TBARS, conjugated diene, lysophosphatidylcholine (lyso PC), oxysterols and less polyunsaturated fatty acids (PUFA) than nLDL. Preincubation of aortas with oxLDL caused a significant inhibition of PGI2 generation compared to aortas preincubated with nLDL or buffer only. The percent inhibition was dependent on the concentration of oxLDL. Most of the inhibitory effect of oxLDL resided in its lipid moiety while the lipid fraction of nLDL, as well as native LDL had no effect. Preincubation of aortas with 10 microg/ml of 7-ketocholesterol the major oxysterol in oxLDL reduced the amount of PGI2 generated by aorta at all times tested; however that decrease did not reach a significant level. Aortas preincubated with 10 microg/ml of lyso PC showed a 21-36% inhibition of PGI2 generation which was comparable to the inhibition produced by preincubating the aortas with 50 microg protein/ml of oxLDL (containing about 7.5 microg lyso PC). This indicated that most of the inhibitory effect of oxLDL was due to its lyso PC. The small molecular weight fraction (< 10 kDa) with a high level of TBARS (TBARS solution) also significantly decreased the PGI2 generation by aorta. Addition of superoxide dismutase (SOD) + catalase or vitamin E simultaneously with oxLDL or TBARS solution in the preincubation medium did not reverse their inhibitory effects. This indicated that oxygen free radicals are not a contributing factor to the inhibitory effect of oxLDL but lyso PC and the lipid peroxides and probably other components already present within oxLDL are the important inhibitors. 相似文献
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Summary Isotope dilution provides a method for measuring plant competition for mineral N and transfer of biologically fixed N from
a legume to a grass. A plant growth medium was enriched with15N, and used to grow Siratro (Macropitilium atropurpureum D.C. Urb.) and Kleingrass 75 (Panicum coloratum L.) in 20 liter pots for 98 days in a glasshouse. The plants were grown in pure stand and in mixtures. When grown in 50∶50
mixture the grass obtained 59% of the labelled N and the legume obtained 41%. The grass produced nearly as much root mass
as the legume even though biomass of the shoots were less than half that of the legume. Reducing the proportion of either
plant species in the mixture reduced the proportion of the mineralized N absorbed by that species. The shoots of the grass
were significantly more enriched (1.166 atom%15N excess) than the roots (1.036). The grass received 12% of its N as biologically fixed N from the legume. 相似文献
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Summary
Quadriacanthus aegypticus n. sp., a monogenean from the gills of Clarias lazera inhabiting Nile delta waters in Egypt, is described. The genus Quadriacanthus Paperna, 1961 is reported for the first time in Egypt. Particular attention has been paid to the reproductive system, the digestive system, the anterior adhesive glands, the posterior body glands and haptoral sclerites. Possible functions of the different internal organs are discussed. The diagnosis of the genus Quadriacanthus is emended. ac]19840926 相似文献
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Mohammed Sbia Marie-Francoise Diebler Nicolas Morel Maurice Israël 《Journal of neurochemistry》1992,59(4):1273-1279
The mediatophore is a presynaptic membrane protein that has been shown to translocate acetylcholine (ACh) under calcium stimulation when reconstituted into artificial membranes. The mediatophore subunit, a 15-kDa proteolipid, presents a very high sequence homology with the N,N'-dicyclohexylcarbodiimide (DCCD)-binding proteolipid subunit of the vacuolar-type H(+)-ATPase. This prompted us to study the effect of DCCD, a potent blocker of proton translocation, on calcium-dependent ACh release. The present work shows that DCCD has no effect on ACh translocation either from Torpedo synaptosomes or from proteoliposomes reconstituted with purified mediatophore. However, using [14C]DCCD, we were able to demonstrate that the drug does bind to the 15-kDa proteolipid subunit of the mediatophore. These results suggest that although the 15-kDa proteolipid subunits of the mediatophore and the vacuolar H(+)-ATPase may be identical, different domains of these proteins are involved in proton translocation and calcium-dependent ACh release and that the two proteins have a different membrane organization. 相似文献
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Mohammed S. Taghour Hazem Elkady Wagdy M. Eldehna Nehal M. El-Deeb Ahmed M. Kenawy Eslam B. Elkaeed Aisha A. Alsfouk Mohamed S. Alesawy Ahmed M. Metwaly Ibrahim. H. Eissa 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):1903
A thiazolidine-2,4-dione nucleus was molecularly hybridised with the effective antitumor moieties; 2-oxo-1,2-dihydroquinoline and 2-oxoindoline to obtain new hybrids with potential activity against VEGFR-2. The cytotoxic effects of the synthesised derivatives against Caco-2, HepG-2, and MDA-MB-231 cell lines were investigated. Compound 12a was found to be the most potent candidate against the investigated cell lines with IC50 values of 2, 10, and 40 µM, respectively. Furthermore, the synthesised derivatives were tested in vitro for their VEGFR-2 inhibitory activity showing strong inhibition. Moreover, an in vitro viability study against Vero non-cancerous cell line was investigated and the results reflected a high safety profile of all tested compounds. Compound 12a was further investigated for its apoptotic behaviour by assessing the gene expression of four genes (Bcl2, Bcl-xl, TGF, and Survivin). Molecular dynamic simulations authenticated the high affinity, accurate binding, and perfect dynamics of compound 12a against VEGFR-2. 相似文献