PARENTERAL SUPPLY OF VITAMIN-A TO SHEEP

A total of 20 sheep was used to study the effect of intramuscular inje ctions of four different doses of vitamin A. One group received the ve hicle only (control group), while the others were injected i.m. with v itamin A. Group 2:1.5x10(6) IU, Group 3: 3x10(6) IU and Group 4:5X10(6 ) IU. There was an increase in plasma vitamin A with increase in vitam in A injection. Sheep injected with 5.0x10(6) IU vitamin A had signifi cantly higher plasma vitamin A concentrations than control sheep. The area under the plasma concentration curve (AUG) tended to increase wit h higher doses of vitamin A injection, and the greatest AUC was observ ed in sheep with 5x10(6) IU of vitamin A. Some proportionality between vitamin A dose given and tissue vitamin A concentration was found, wi th the liver containing the highest concentration within tissues. This organ is the most reliable index of vitamin A body storage. Linear re gressions of log tissue concentrations on plasma concentrations were m ostly not significant except for adrenal, and the slope ranged from -0 .24 to 0.69. The results showed that parenteral administrations of hig h (5.0x10(6) IU) doses of vitamin A in sheep increase significantly th e concentrations of this vitamin in liver and caution should be taken on the consumption of liver by humans.