Metabolism of the vitamin D3 derivative (24R)-hydroxycalcidiol by human promyelocytic leukemia cells (HL-60). Isolation and identification of (5Z) and (5E)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol.
Human promyelocytic leukemia cells (HL-60 cells) incubated with (24R)-hydroxy[26,27-methyl-3H]calcidiol (0.2 microCi) or non-radioactive (24R)-hydroxycalcidiol (370 micrograms) produced significant quantities of two new vitamin D3 (calciol) metabolites. The metabolites were isolated from HL-60 cell culture media by methanol/chloroform extraction and a series of chromatographic procedures. The two new metabolites were identified as (5Z)- and (5E)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol by HPLC analysis, ultraviolet absorption spectrophotometry, mass spectrometry and Fourier-transform infrared spectrophotometry. According to the isolation and purification procedures, the total amounts of 3.04 micrograms (5Z)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol (lambda max = 310 nm, epsilon = 17070 M-1 cm-1) and 8.89 micrograms (5E)-(24R)-19-nor-10-oxo-24-hydroxycalcidiol (lambda max = 312 nm, e = 24,500 M-1 cm-1) were calculated, assuming an Mr of 418. The activity of 19-nor-10-oxo-(24R)-hydroxycalcidiol to promote HL-60 cell differentiation was higher than the activity of the precursor (24R)-hydroxycalcidiol suggesting a possible biological action of this metabolite in HL-60 cells.
D015650:24,25-Dihydroxyvitamin D 3; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D005434:Flow Cytometry; D006801:Humans; D006887:Hydroxycholecalciferols / Q000378:metabolism*; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D013058:Mass Spectrometry; D010587:Phagocytosis; D013053:Spectrophotometry; D013237:Stereoisomerism; D014316:Tritium
D006887:Hydroxycholecalciferols; C030711:24-hydroxyvitamin D3; D014316:Tritium; D015650:24,25-Dihydroxyvitamin D 3