Sonoko Masuda

Regulatory activities of 2β-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3, a novel synthetic vitamin D3 derivative, on calcium metabolism

Regulatory activities of 2β-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3 [ED-71], a novel synthetic vitamin D3 derivative, on calcium metabolism were investigated. The compound behaved similar to 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] in the ex vivo intestinal calcium transport using rat everted gut sac and the in vivo bone mobilization using vitamin D-deficient rats. By means of Raiszs assay method, 45Ca releasing activity of ED-71 was not greater than that of 1,25(OH)2D3. The time course curve of ED-71 in plasma made a mild round shape compared with that of 1,25(OH)2D3 and the formers plasma concentration remained increased longer than the latters. The therapeutic effect of ED-71 for the animal models with osteoporosis seemed to be better than that of 1,25(OH)2D3. The results suggest that ED-71 may be a promising drug for therapy of osteoporosis.

2β-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3 (ED-71), preventive and therapeutic effects on bone mineral loss in ovariectomized rats

Abstract 2β-(3-Hydroxypropoxy)-1α,25-dihydroxyvitamin D3 (ED-71) improved bone mineral density and mechanical bone strength in the pre-osteoporosis and osteoporosis model rats made by ovariectomy more effectively than 1α,25-dihydroxyvitamin D3.

A method for the simultaneous determination of vitamins D2,D3 and their metabolites in plasma and its application to plasma samples obtained from normal subjects and patients

Abstract A method has been established for the simultaneous determination of vitamins D2,D3 and their metabolites in plasma. Vitamin D 2 D 3 , 25-hydroxyvitamin D 2 D 3 24R,25-dihydroxyvitamin D 2 D 3 [ 24,25( OH ) 2 D 2 D 3 ] and 1α,25-dihydroxyvitamin D 2 D 3 [ 1,25( OH ) 2 D 2 D 3 ] in 1.5 ml of a plasma sample were simultaneously assayed. The method includes extraction of lipid, followed by three steps of high-performance liquid chromatography (HPLC) for clean-up and separation. Vitamin D 2 D 3 and 25- OH - D 2 D 3 were quantified by a UV detector, while 24,25( OH ) 2 D 2 D 3 and 1,25( OH ) 2 D 2 D 3 were assayed by competitive protein binding assay (CPBA) and radioreceptor assay (RRA) methods, respectively. Existing interfering substances in a sample could be effectively eliminated by HPLC and reliable results with small coefficients of variation were obtained. The method was applied to plasma samples obtained from normal subjects and patients with epilepsy, liver cirrhosis, leukaemia, diabetes, sensorineural deafness and hypophosphataemic osteomalacia; satisfactory results were obtained.