Update 1999 On the Vitamin D Endocrine System: Implications for Osteoporosis.

摘要

It is now generally accepted that the biological responses that are mediated by vitamin D occur as a consequence of the integrated actions of 1 alpha , 25(OH)D and 24R, 25(OH)D interacting with the many receptors for these seco steroids which are present in the over 30 target organs which comprise the vitamin D endocrine system. The biological responses are principally generated by 1 alpha , 25)OH)D interacting with either or both the nuclear (nVDR) and membrane localized (MVDR) receptors which respectively initiate a signal transduction process involving regulating of gene transcription (nVDR) and the opening of voltage gated Ca channels (mVDR). There is evidence that indicates the nVDR and mVDR are different proteins with ligand blinding domains with different structural preferneces.