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41.
Inhibitory effects of danazol, an isoxazol derivative of synthetic steroid 17 alpha-ethinyl-testosterone, on the development of uterine adenomyosis, a pathological disorder of endometrial tissue defined as the presence of endometrial glands and stroma in the myometrium, were investigated in mice of SHN strain. Mice treated with 0.5 microgram danazol for 5 weeks during 4-9 weeks of age and killed at 21 weeks of age showed significantly lower incidence of the spontaneous development of adenomyosis than the age-matched intact control mice. The inhibitory effects of danazol were also evident in mice bearing pituitary isografts which were effective in inducing an early and a high incidence of adenomyosis. Furthermore, the treatment with danazol resulted in the decrease of serum levels of luteinizing hormone (LH) and prolactin (PRL) associated with hypofunction of ovaries and persistent diestrus. These results support the usefulness of danazol for the clinical treatment of gynecological disorders except for hypofunction of ovaries. 相似文献
42.
YM175, a new bisphosphonate, increases serum 1,25-dihydroxyvitamin D in rats via stimulating renal 1-hydroxylase activity 总被引:1,自引:0,他引:1
Y Nagao Y Ishitobi H Kinoshita S Fukushima H Kawashima 《Biochemical and biophysical research communications》1991,180(3):1172-1178
Effect of YM175, a new bisphosphonate, on vitamin D metabolism was studied in rats. When animals were treated with the compound, serum 1,25-dihydroxyvitamin D increased in a dose dependent manner. The effect was also detected in thyroparathyroidectomized animals. The effect appears to be due to the stimulation of renal production of the hormone, since renal 1-hydroxylase was also elevated in these animals. However, when kidneys were incubated with YM175 and then renal 1-hydroxylase activity was examined, the enzyme activity was not different from that of non-treated control kidney. We conclude therefore that YM175 indirectly stimulates renal 25-hydroxyvitamin D-1-hydroxylase by increasing circulating parathyroid hormone via an unknown mechanism independent of parathyroid hormone. This is the first direct demonstration of increase in the renal production of 1,25-dihydroxyvitamin D resulting from bisphosphonate treatment. 相似文献
43.
H Kawashima 《Biochemical and biophysical research communications》1990,166(2):709-714
The effect of parathyroid hormone on intracellular calcium concentration in vascular smooth muscle cells in culture was studied. Human PTH 1-34 (hPTH (1-34)) caused a transient rise in intracellular calcium in a dose-dependent manner at physiological concentrations. The effect of PTH was mimicked by dibutyryl cyclic AMP and inhibited by a PTH receptor antagonist. The effect of PTH was increased in parallel with extracellular calcium concentration and a sustained response was observed when extracellular calcium was 2 mM or higher. The PTH action was blocked by nisoldipin, a calcium antagonist, but not by ouabain, a Na, K-ATPase inhibitor. These data indicate that PTH increases intracellular calcium through its receptor via opening calcium channels. A possible role of this effect in the regulation of vascular tone is also discussed. 相似文献
44.
Sumio Iwai Kazuo Nakata Teruyoshi Nagao Nobumaro Kawashima Susumu Matsuyama 《Planta》1981,152(5):478-480
Nine plants were produced from anthers of a somatic hybrid which had been obtained by fusion of Nicotiana tabacum L. and N. rustica L. protoplants. As determined by electrofocusing, the Fraction I protein of the original somatic hybrid had largesubunit polypeptides exclusively of the N. tabacum type. Two of the plants regenerated from anthers contained Fraction-I-protein large subunits exclusively of the N. rustica type. Since each plant was regenerated from a single cell, the somatic hybrid must have had cells containing both the N. tabacum and N. rustica chloroplast genome although the latter was not expressed. Possibilities to account for this non-expression of a chloroplast genome in the somatic hybrid are discussed. 相似文献
45.
Shinkichi Kamata Akira Okada Takehiko Watanabe Yasunaru Kawashima Hiroshi Wada 《Journal of neurochemistry》1980,35(5):1190-1199
The etiologic relationship between disturbances in metabolism of amino acids and amines and hepatic coma was investigated by examining the effects of diets containing various mixtures of amino acids on brain amine metabolism in rats with a portacaval shunt, using a method for simultaneous analysis of amino acids and amines. Rats with a portacaval shunt were fed on four different amino acid compositions with increased amounts of various amino acids suspected to be etiologically related to hepatic coma, such as methionine, phenylalanine, tyrosine, and tryptophan. The animals were killed 4 weeks after operation. During the experimental period, these animals did not become comatose, but exhibited various behavioral abnormalities. Marked increase in the plasma and brain levels of the augmented amino acids, especially methionine and tyrosine, were observed in rats with a portacaval shunt. Brain noradrenaline, dopamine, and serotonin levels were significantly decreased when the brain tyrosine level was increased. These results indicate that in rats with a portacaval shunt the dietary levels of amino acids greatly influence the brain levels of both amino acids and transmitter amines. 相似文献
46.
The substrate specificity of spermidine dehydrogenase from Serratia marcescens was studied using many kinds of naturally occurring and synthetic polyamines. Diamines inhibited the enzyme competitively and their inhibitor constants tended to decrease with increasing methylene chain length in the diamines. All of the triamines and tetramines examined were active as substrates, and the amines containing a 4-aminobutylimino moiety (NH2(CH2)4NH-) in their structures were more active. N-Alkylputrescine was also oxidized by the enzyme. All of the amines containing a 4-aminobutylimino group were oxidized to form 1-pyrroline stoichiometrically as one of the products. Tetramines containing a 3-aminopropylimino group (NH2(CH2)3NH-) were oxidized to form 1,3-diaminopropane. However, in the case of an amine containing both 4-aminobutylimino and 3-aminopropylimino groups, the imino moiety of the former was preferentially oxidized by the enzyme. On the basis of the substrate specificity, the binding characteristics of the enzyme are discussed and a subsite model for the binding site is proposed. 相似文献
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49.
Tetsuya Kawai Iwase Kazuhiko Noriko Takaya Yuko Yamaguchi Ryuta Kishii Yasushi Kohno Haruaki Kurasaki 《Bioorganic & medicinal chemistry letters》2017,27(4):1045-1049
We attempted to optimize sulfonamide-based non-alkyne LpxC inhibitors by focusing on improvements in enzyme inhibitory and antibacterial activity. It was discovered that inhibitors possessing 2-aryl benzofuran as a hydrophobe exhibited good activity. In particular, compound 21 displayed impressive antibacterial activity (E. coli MIC = 0.063 μg/mL, K. pneumoniae MIC = 0.5 μg/mL, and P. aeruginosa MIC = 0.5 μg/mL), and is a promising lead for further exploration as an antibacterial agent. 相似文献
50.