Epidemiological and laboratory data support a role for vitamin D in the growth and differentiation of human prostatic cells. These findings prompted us to ask whether prostatic cells could convert 25-hydroxyvitamin D3 (25-OH-D3), the major circulating metabolite of vitamin D3, to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3J, the hormonally active metabolite, in a manner similar to cultured human kera...

The present study was undertaken to investigate the mechanism by which 1α, 25-dihydroxy-cholecalciferol [1α,25-(OH)₂-VD₃] modulates the differentiation of mouse 3T3-L1 preadipocytes into mature adipocytes. Treatment with 1α,25-(OH)₂-VD₃ in the presence of insulin, dexamethasone and 3-isobutyl-1-methyl-xanthine significantly inhibited the triacylglycerol accumulation, and mRNA expressions of adi...

this study was carried out to investigate the effects of 1, 25-dihydroxycholecalciferol (1, 25 (oh)2 d3) and root hydroalcoholic extract of withania somnifera (ws) root on performance, mineral retention, bone mineralisation and mechanical characteristics of broiler chicks. treatments were arranged factorially (2×3×2) consisted of a positive control with adequate ca and a negative control diet (...

This study aims to compare 25-hydroxy vitamin D3 (25(OH)D3), adiponectin (ADPN) and apolipoprotein A5 (apoA5) levels among subjects with different glucose tolerance and to explore their correlation with lipid metabolism. Subjects were divided into 98 cases of type 2 diabetes mellitus (T2DM group), 87 cases of impaired glucose regulation (IGR group) and 100 cases of normal glucose tolerance (NGT...

We examined the responsiveness of cultured dermal fibroblasts from biopsies of uninvolved and involved areas of skin from six patients with psoriasis to the cell-proliferation-inhibition activity of 1,25-dihydroxyvitamin D3 (1,25-(OH)2-D3). Cultured fibroblasts from age-matched controls responded to 1,25-(OH)2-D3 (at 0.01, 1, 10, and 100 microM) in a dose-dependent fashion, whereas cultured pso...

The hypothesis that 1,25-dihydroxyvitamin D3 [1,25-(OH)2 vitamin D3] modulates vascular smooth muscle contractile function was tested. 1,25-(OH)2 vitamin D3 (50 ng/day) was administered by intraperitoneal injection over a 3-day period to 13-15-week-old male spontaneously hypertensive and Wistar-Kyoto normotensive rats. On the fourth day, serum was prepared and contractile force generation of is...

25-Hydroxyvitamin D3-1 -hydroxylase (25(OH)D3-1 -hydroxylase), the key enzyme of 1 ,25-dihydroxyvitamin D3 (1,25(OH)2D3) production, is expressed in monocyte-derived macrophages (MACs). Here we show for the first time constitutive expression of 25(OH)D3-1 -hydroxylase in monocyte-derived dendritic cells (DCs), which was increased after stimulation with lipopolysaccharide (LPS). Accordingly, DCs...

Prostate cells contain specific receptors for 1α,25-dihydroxyvitamin D [1α,25(OH)(2)D] or calcitriol, the active form of vitamin D. 1α,25(OH)(2)D is known to inhibit the proliferation and invasiveness of prostate cancer cells. These findings support the use of 1α,25(OH)(2)D for prostate cancer therapy. However, 1α,25(OH)(2)D can cause hypercalcemia, analogs of 1α,25(OH)(2)D that are less calcem...

Specific binding of 1 alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] to macromolecular components in the cytoplasm and nucleus is demonstrated in parathyroid glands of vitamin-D-deficient chicks. The interaction of 1alpha,25-(OH)2D3 with the cytoplasmic binding component is of high affinity (Kd = 3.2 X 10(-10) M) and high specificity [1alpha,25-(OH)2D3 greater than 25-hydroxyvitamin D3 greate...

A slowly inactivating inward calcium current was identified in the rat osteosarcoma cell line ROS 17/2.8 using a combination of ion flux and electrophysiological techniques. Voltage dependence, dihydropyridine sensitivity, divalent cation selectivity, and single channel properties identified this current as a high threshold, "L-type" calcium current. Ion flux experiments using 45Ca2+ confirmed ...