Vitamin B-6 content of plasma of domestic animals determined by HPLC, enzymatic and radiometric microbiological methods.
In the course of searching for a good animal model of human vitamin B-6 metabolism, it was discovered that plasma from pigs fed natural diets contained substances that interfered with the HPLC analysis of vitamin B-6. To determine the extent of such interference, plasma from several other species was examined. In addition to the HPLC method, the samples were analyzed by an apotyrosine decarboxylase method and a radiometric microbiological assay. In cats and dogs good correlation was obtained between pyridoxal phosphate concentrations determined by the HPLC and by the enzymatic method (r = 0.973). Also there was good correlation between total vitamin B-6 concentrations determined by HPLC and by radiometric microbiological assay (r = 0.998). Severe interference in the HPLC assay was encountered in plasma from pigs and herbivorous animals including goats, cattle, horses and sheep. The interference was eliminated in a pig fed a purified diet for 5 days. Average plasma pyridoxal phosphate concentrations range from 29 nM in pigs to 2443 nM in cats. This wide range indicates that there may be significant differences between species in dietary B-6 intake and/or metabolism of vitamin B-6.
D000818:Animals; D002415:Cats; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D006041:Goats; D006736:Horses; D008828:Microbiological Techniques; D011736:Pyridoxine / Q000097:blood*; D012756:Sheep; D013045:Species Specificity; D013552:Swine
D011736:Pyridoxine