Abstract
The level of the four types (pyridoxal, pyridoxamine and their phosphates) of vitamin B_6 in blood of rabbit had been investigated at different time after an oral administration of vitaimin B_6 derivatives, including N-(4-pyridoxyl) dehydrohomocysteine thiolactone (PAL-DHT). After an oral administration of PAL-DHT to rabbit, total vitamin B_6 level in blood was markedly greater than that of administration of other vitamin B_6 derivatives, and reached a maximum 4 hours later, and about 80% of total vitamin B_6 was recovered as pyridoxamine phosphate (PAM-P). When PAL-DHT was injected in the ligated intestine in situ, a large quantity of PAM-P in the mesentric vein blood was recovered. These findings suggested that PAL-DHT might be readily metabolized to PAM and phosphorylized to PAM-P in the transporting process through the intestinal wall. And the differential patterns were observed in the increased level of vitamin B_6 in blood after administration of PAL plus DL-Homocysteine mixture and PAL-HCySH. Also the half-life of total vitamin B_6 in blood after oral administration of vitamin B_6 derivatives were calculated respectively.
