ergocalciferol brands

Molecular formula: C28H44O

For its activity, ergocalciferol is required to be transformed to its major active circulating hydroxylated metabolite and transported to the target organs in order to bind to its target, the vitamin D receptor. The activation of the vitamin D receptor is part of the vitamin D endocrine system and it is described by the production of a change in the transcription rates of the vitamin D receptor target genes. The target genes in the DNA affected by the presence of ergocalciferol are called vitamin D response elements which are dependent on co-modulators. The vitamin D receptor is a transcription factor and member of the steroid hormone nuclear receptor family. It presents a DNA binding domain (VDRE) that, when activated, recruits coregulatory complexes to regulate the genomic activity. Additionally, ergocalciferol presents nongenomic effects such as the stimulation of intestinal calcium transport via transcaltachia. The mechanism of action of calcitriol, the activated form of vitamin D, resembles that of the steroid and thyroid hormones. Thus, calcitriol binds to cytosolic receptors within target cells, and the receptor-hormone complex interacts with the DNA of certain genes to either enhance or inhibit their transcription. Structural analysis of the calcitriol receptor indicates that it belongs to the same supergene family as the steroid receptors. Calcitriol also appears to exert a few effects that occur too rapidly to be explained by genomic actions. /Calcitriol/ The mechanisms responsible for mobilization of bone salts have been only partially defined, and the interaction of multiple factors appears to be involved. Paradoxically, the cells responsible for bone resorption (osteoclasts) are not directly acted upon by calcitriol and do not appear to contain calcitriol receptors. Instead, calcitriol causes an increase in the number of osteoclasts available to resorb bone; this may result from an action upon myeloid hematopoietic precursor cells that are induced to differentiate toward functional osteoclasts. The cells responsible for bone formation (osteoblasts) do contain receptors, and calcitriol causes them to elaborate several proteins, including osteocalcin, a vitamin K-dependent protein that contains gamma-carboxyglutamic acid residues. The exact role of this protein is not known, but other unidentified substances are also elaborated that appear to stimulate the function of osteoclasts. In addition, calcitriol acts synergistically with gamma-interferon to increase the production of interleukin-1, a lymphokine that promotes bone resorption.

Source: PubChem (NCBI) · compound 5280793