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Alfacalcidol, the prodrug of calcitriol, was brought onto the market in Japan in 1981 as a therapeutic agent for bone disease associated with vitamin D (D) metabolic diseases, and was approved in 1983 as a treatment for osteoporosis. The use of calcitriol and its analogs for the treatment of osteoporosis is still controversial intemationally. However, recent studies suggest that the adminisstration of a nutritional supply of D (400〜800 IU) or high doses of calcium agents are not effective in the treatment of osteoporotic Patients with intestinal calcium malabsorption and dysfunction of renal D activation. To bring about recovely of the physioological functions and maintain bone in its normal condition, it is necessary to administer the active form of D with RDA equivalent of Ca intalke. After the finding of the differentiation-inducing activities in 1981 by E. Abe et al, new analogs of D were synthesized on the basis of the idea of separating differentiation-inducing activities from calciumregulating activities by modifying the calcitriol chemical structure. Thus, 22-oxa-calcitriol (OCT) and 2β (3hydroxypropoxy) calcitriol (ED-71) were synthesized by organic chemists at Chugai. Both OCT and ED-71 have been shown to have thelapeutic value. Reports on OCT and ED-71, together with reports on calcipotriol and KH1060 by Leo, and 19nor-1α, 25 (OH)_2 D_2 by Abbot vigorously stimulated research world-wide in the development of D analogs into pharmaceutical products. In Endocrine Reviews, 1995, Bouillon et al summarized reports of the early active research on D analogs. These reviews prompted mamy researchers to discover newer and superior D analogues such as 3-epi-1α, 25 (OH)_2 D_3, 19-nor (3β)-1α, 25 (OH)_2 D_3, 18-nor 1α, 25 (OH)_2 D_3, 2-methyl-20-epi-calcitriiol, non-steroidal D and others. We are convinced that various D analogs will appear as highly effective therapeutic agents at the clinical level in the coming century, and also that a new theory of the mechanism of D wili be produced in the near future.

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Simon's metabolites (α-tocopheronic acid and its γ-lactone) have long been thought to be the main metabolites of α-tocopherol in urine. Based on these metabolites a hypothetical scheme for the biological formation was proposed (via the tocopheryl quinone route). From the initial detection of a carboxyethyl hydoxychroman (CEHC)-type metabolite of δ-tocopherol (via the retention of the chroman ring route) in rat udne, corresponding metabolites of α-tocopherol and γ-tocopherol were subsequently found. It is particularly interesting that γ-CEHC (LLU-α) was found in human urine as a natriuretic factor. Whether Simon's metabolites are physiologically significant or are artifacts due to postchemical treatment is not certain at preseot. To identify them as conjugated forms is wananted. The lack of intermediary metabolites of vitamin E homologues still remains as a missing link of vitamin E catabolism.

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To evaluate antioxidant vitamin status in young women, serum retinol, α-tocopherol, and total ascorbic acid levels were determined in 284 female students aged 21〜22 years, and serum β-carotene in 162 females. Dietaory vitamin intakes were assessed by a 3-day food record immediately before the day of blood-collecting. The intakes of vitamin A, vitamin E and vitamin C in 50.0 %, 32.7 %, and 50.4 % of students had been fulfilled their RDAs, respectively. The 59 % of dietary vitamin A intakes were from β-carotene (n=162). The mean of energy intake was low (1581 ± 303 kcal). A significant correlation was observed for only β-carotene between serum level and dietary intaake. The 2.5〜97.5 % distribution ranges and mean ± SD of serum vitamin levels were obtained from the subjects with dietary vitamin intake above RDA:0.20〜0.72 (0.42 ± 0.12) mg/l for retinol, 6.1〜22,0 (12.2 ± 3.1) mg/l for α-tocopherol, 7.2〜16.8 (12.3 ± 2.1) mg/l for ascorbic acid. That of serum β-carotene was 0.13〜2.00 (0.67 ± 0.11) mg/l calculated from all the subjects.

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To clarify the vitamin B_<12> (B_<12>) and folate status in young women, serum B_<12> and folate levels were determined in 252 female students aged 21〜22 years, and their dietaly intakes were assessed from a 3-day food record. The serum vitamin levels were measured by chemiluminescence competittiive binding assay using ACS-B12/Folate (Bayer Medical). The mean of serum B_<12> and folate levels, and the lower limit of 95 % confidential interval for serum folate were 10 %, 34 % and 49 % higher by ACS than by Elecsys VB12/Folate (Roch Diagnostics). The energy intake (1633 ± 296 kcal/day) was lower than the RDA, The B_<12> intake was 4.79 ± 3.55 μg/day, and folate intake was 190.6 ± 70.0 μg/day, and 76.7 % and 40.2 % of the students had been fulfilled their RDAs of the former and the latter, respectively A Significant correelation was found only between serum folate level and dieetary intakes. The 2.5〜97.5 % distribution range of serum B_<12> was 300〜1160 (638.0 ± 199.3) pg/ml and that of folate was 4.6〜13.5 (8.34 ± 2.04) ng/ml, which were obtained from the subjects with their vitamin intakes above RDAs.

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