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Shigeaki KATO
Article type: Article
1996 Volume 70 Issue 5-6 Pages
217-233
Published: June 25, 1996
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Recent discovery of nuclear retinoid receptors revealed that a variety of retinoid (vitamin A) action is exerted by the nuclear receptors-mediated gene expression. Nuclear retinoid receptors are classified into two classes, all-trans-retinoic acid receptors (RARα, β and γ) and retinoid-X-receptors (RXRα,β and γ). Ho- mo- and hetro-dimers of RAR and RXR bind to specific retinoid response elements (RARE and RXRE) located in the target gene promoters. These response elements are composed of two direct repeated AGGTCA motifs (or related motif) spaced by 1,2 and 5bp (DR 1,2 and 5). Based upon these observations, the molecular mechanisms of retinoid actions were considered from different experimental approaches. By extending our previous findings in unusual estrogen response elements, other classes of retinoid response elements have been identified from systematic studies. Using animal models of various status of retinoid, vitamin D and thyroid hormone, we found that the gene expression of RARβ our of three RARs is positively regulated at transcriptional level by retinoid, but not vitamin D and thyroid hormone. In the contrast, the gene expression of RXRβ (positive) and RXRγ (negative) is regulated transcriptionally and post-transcriptionally by only thyroid hormone. Furthermore, the effects of these three ligands on the gene expression of cellular retinoid binding proteins are under investigation. In addition, isomerization of active form of retinoic acids and the functional domain of RAR and RXR with special attention to phosphorylation are also studied. Thus, taken together, these studies may clarify a part of the molecular mechanisms of retinoid actions.
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Akio OTA, Masato NISHIKAWA, Hiroshi SATO, Atsushi KOGA, Makoto SHIMIZU ...
Article type: Article
1996 Volume 70 Issue 5-6 Pages
235-240
Published: June 25, 1996
Released on J-STAGE: December 26, 2017
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Capillary basement membrane thickening is a characteristic of diabetic microangiopathy. Type IV collagen is the major component of basement membrane. To elucidate the pathogenesis of diabetic nephropathy, we investigated serum type IV collagen and serum ascorbic acid in non-insulin-dependent diabetes mellitus (NIDDM) (n=37) and in normal subject s (n=14). Serum ascorbic acid level was lower in NIDDM than in normal subjects. Serum type IV collagen level was higher in NIDDM than in normal subjects. There was a significant positive correlation between serum type IV collagen and HbA_<IC> in poorly controlled diabetes (HbA_<IC>>8%) (p<0.05). A significant negative correlation was found between serum type IV collagen and serum ascorbic acid (p<0.05). A significant positive correlation was found between serum type IV collagen and urinary albumin excretion in patients with microalbuminuria (U-alb>30 mg/g・Cr) in NIDDM. In conclusion, serum type IV collagen is helpful as a early indicator of nephropathy.
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Masaru TSUJIMURA, Shizu HIGASA, Takamasa KASAI
Article type: Article
1996 Volume 70 Issue 5-6 Pages
241-248
Published: June 25, 1996
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A rapid progress in high performance liquid chromatography (HPLC) has been made recently and various procedures to apply it for differential determination of total vitamin C (AsA plus DAsA) in foods have been examined. In this report, we describe a method for total vitamin C determination by HPLC using 2,4-dinitrophenylhydrazine (DNPH) as the internal standard. (1) Addition of DNPH in a range of 100-1000μg/ml (AsA standard) hardly influenced the peak area of the remaining DNPH in the reaction system after the formation of osazone. (2) When shaking extraction was carried out for 5 min after the addition of ethyl acetate, the peak area of DAsA osazone in the chromatograms reached to the maximum, indicating that 5 min of shaking time is optimum for extraction. (3) The amounts of total vitamin C in 33 kinds of foods on the market were determind by using HPLC, TLC and DNPH method, and the results were compared among these three methods. The amounts estimated by the present HPLC method were close to those by TLC method and similar or lower than those by DNPH method. (4) The recovery of added total vitamin C was 95-106% for the present method. (5) Total vitamin C can be determined in concentrations 0.5 mg per 100 g of food.
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Article type: Appendix
1996 Volume 70 Issue 5-6 Pages
249-251
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
253-255
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
255-257
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
257-260
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
260-262
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
262-265
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
265-267
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
267-268
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
268-270
Published: June 25, 1996
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
271-272
Published: June 25, 1996
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
272-273
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
273-274
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
274-275
Published: June 25, 1996
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T. Josseph, D.B. McCormick
Article type: Article
1996 Volume 70 Issue 5-6 Pages
275-
Published: June 25, 1996
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
275-276
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
276-277
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
277-278
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
278-279
Published: June 25, 1996
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[in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
279-280
Published: June 25, 1996
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
280-281
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
283-285
Published: June 25, 1996
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[in Japanese], [in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
285-287
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
287-288
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
289-290
Published: June 25, 1996
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[in Japanese]
Article type: Article
1996 Volume 70 Issue 5-6 Pages
290-292
Published: June 25, 1996
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