8 research outputs found
抗原誘発性Th1・Th2サイトカイン産生に対する性ホルモンの影響の性差
The incidence, severity and prognosis of asthma can be affected by a number of factors, including the patient\u27s age and sex. Clinical observations and epidemiologic studies indicate that the prevalence and severity of asthma is higher among boys than girls, but that the ratio inverts after puberty. The reversal of the male/female prevalence of asthma at puberty strongly suggests a role of sex hormones. However, the mechanisms underlying the gender differences in the prevalence of asthma are not clear. Recently, we suggested that the sex differences were due to those in not only sex hormones but also lymphocyte functions based on findings in a murine model of allergic asthma. Therefore, we investigated the effect of sex hormones on antigen-induced cytokine production by lymphocytes to further investigate these gender differences. Splenocytes from ovalbumin (OVA)-sensitized female mice produced more IL-5, Th2 cytokine, than those from OVA-sensitized male mice, upon simulation with OVA. Progesterone decreased the production of IFN-g, Th1 cytokine, by splenocytes from both sensitized male and female mice. 17β-estradiol had no effect on Th1 and Th2 cytokine production by splenocytes from both mice. However, 5a-dihydrotestosterone decreased the production of Th2 cytokines by splenoytes from sensitized female mice but not these from male mice. Our findings suggest that lymphocytes from males and females have different sensitivities to sex hormones in antigen-induced cytokine production
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Suppression of mammary tumors by oral administration of 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil in SHN virgin mice
Chronic oral administration of 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil suppressed not only de novo but also salvage pathways for pyrimidine nucleotide synthesis, and reduced mammary tumorigenesis and tumor growth in SHN virgin mice, which have a high potential for the incidence of mammary tumors
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Effects of Danazol on endometrial DNA synthesis in rats
The suppressive effects of Danazol, an isoxazol derivative of the synthetic steroid 17 α-ethinyltestosterone, on endometrial DNA synthesis were investigated in rats by immunohistochemistry with bromodeoxyuridine (BrdU) and DNA-synthesizing enzyme assays. Rats treated with Danazol for 14 days at 17–19 weeks of age showed a decrease of plasma gonadotropins associated with ovarian hypofunction, persistent diestrus, and a smaller number of corpora lutea in ovary, resulting in no BrdU-immunoreactive (S-phase) cells in endometrial epithelium and lower activity of thymidine kinase in the uterus compared with control
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Effects of Kampo (Japanese Herbal) Medicine “Sho-Saiko-To” on DNA-Synthesizing Enzyme Activity in 1,2-Dimethylhydrazine-Induced Colonic Carcinomas in Rats
Abstract
Sho-Saiko-To (SST) is a modified Japanese traditional Chinese herbal medicine containing seven medical plants: Bupleuri radix, Pinelliae tuber, Suxtallariae radix, Zizyphi fructus, Ginseng radix, Glycyrrhizae radix, and Zingiberis recens rhizoma. This preparation has been used in the treatment of some inflammatory diseases of the respiratory system and chronic hepatitis. In the present study, the effects of SST were investigated on the activities of DNA-synthesizing enzymes in 1,2-dimethylhydrazine (DMH)-induced colonic carcinomas in rats. Six-week administration of SST prevented nearly 100% of the body weight loss and the final number of the colonic carcinomas compared to those in the rats treated with DMH alone, and suppressed the enhanced activities of thymidylate synthetase (TS) and thymidine kinase (TK) which were involved in the DE NOVO and salvage pathways of pyrimidine synthesis, respectively, in DMH-induced colonic carcinomas. These results indicate that SST may show directly and/or indirectly inhibitory effects on the development of colonic carcinomas
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Suppression by Kampo Medicines in Preneoplastic Mammary Hyperplastic Alveolar Nodules of SHN Virgin Mice
Abstract
Sho-saiko-to (SST), Keishi-bukuryo-gan (KBG), and Shakuyaku-kanzo-to (SKT) are Japanese modified traditional Chinese herbal medicines (Kampo medicines) consisting of 7, 5, and 2 medical plants, respectively. It is known that the hyperplastic alveolar nodule (HAN) is a representative preneoplastic state in the mammary glands of mice. We examined the effects of SST, KBG, and SKT on the formation and growth of HAN in a high-mammary-tumor strain of SHN virgin mice. Oral administration of SST for 60 days beginning at 90 days of age reduced the number and area of HAN and mammary thymidylate synthetase activity with a reduction of serum prolactin level. There was little difference between the other experimental groups and the control in the formation and growth of HAN and the enzyme activities. These results indicate that SST may have a preventive effect on malignant mammary transformations