Flachowsky G, Wilk M, Ochrimenko W I, Geinitz D, Richter G H, Henning A
Sektion Tierproduktion und Veterinärmedizin, Universität Leipzig.
Arch Exp Veterinarmed. 1991;45(1):93-100.
The effect of one single oral or parenterally administered dose of 1 million IU vitamin A on the vitamin A depot in the liver and on blood plasma vitamin A concentrations was investigated in 3 individual feeding experiments with involvement of 18 and 24 calves or 24 fattening bulls. 50% of all animals in each of the 3 experiments received feed without any vitamin A through 108 or 112 or 209 days, prior to vitamin A administration, or received 10.000 IU/100 kg live weight and day. Parenteral vitamin A administration in either group yielded rise in blood plasma from 0.06--0.35 to 26.2--30.2 mumol/l, after 1 or 2 days. The maximum value measured after oral administration was 1.9 mumol/l. Most of the plasma values had returned to normal (0.6--12. mumol/l) within 14 days from administration. Oral and parenteral vitamin A doses, after 14 days, caused significant rise in vitamin A concentrations in the liver (from 15.5 to 82.5), with the increase resulting from parenteral administration (from 13.7 to 99.1) being clearly higher than that resulting from oral administration (from 17.3 to 65.9 mumol/kg fresh liver tissue). The same trends were recorded from recovery of vitamin A from the liver (26.8% after parenteral administration versus 15.0% in the wake of oral doses). Storage in and recovery from vitamin-A depleted animals were below values recorded from young cattle with sufficient vitamin A supply. These findings are likely to confirm that one single parenteral vitamin A administration was of clearly higher effectiveness, as compared to oral application.
在涉及18头和24头犊牛或24头育肥牛的3项个体饲养实验中，研究了单次口服或肠胃外给予100万国际单位维生素A对肝脏中维生素A储备和血浆维生素A浓度的影响。在3项实验中的每一项里，50%的动物在给予维生素A之前的108天、112天或209天内食用不含任何维生素A的饲料，或者按每100千克活体重每天给予10000国际单位维生素A。两组中通过肠胃外给予维生素A后，1天或2天后血浆中维生素A浓度从0.06 - 0.35微摩尔/升升至26.2 - 30.2微摩尔/升。口服后测得的最大值为1.9微摩尔/升。给药后14天内，大多数血浆值恢复正常（0.6 - 1.2微摩尔/升）。14天后，口服和肠胃外给予的维生素A剂量均使肝脏中维生素A浓度显著升高（从15.5升至82.5），肠胃外给药引起的升高（从13.7升至99.1）明显高于口服给药引起的升高（从17.3升至65.9微摩尔/千克新鲜肝脏组织）。从肝脏中回收维生素A也记录到相同趋势（肠胃外给药后为26.8%，口服给药后为15.0%）。维生素A缺乏动物体内的储存量和回收量低于维生素A供应充足的幼畜所记录的值。这些发现可能证实，与口服相比，单次肠胃外给予维生素A的效果明显更高。
