Comparison of oral and intramuscular administration of vitamins A and E on the concentrations of vitamins A and E in blood plasma and different tissues and availability of the vitamins from storage tissues of Iranian fat-tailed sheep (Moghani breed)

In this study, 23 fat-tailed rams of Moghani breed weighing 45 - 55 kg were assigned to a control (n = 4) and two treatment groups. One treatment group (n = 10) received 4500 IV !head of vitamin E (dissolved in sesame oil) through intramuscular (i.m.) administration. The other group (n = 9) received vitamin E orally (100 IUlkg body weight). Chemically, both of the vitamins were composed of dl-alpha-tocopheryl acetate. Blood samples were taken from four sheep (jugular vein) belonging to orally-administrated group on the 3rd day and then were slaughtered for tissue sampling. Blood samples, also were taken from the control and both treated groups (5 head/group) at the hours of zero, 2, 4, 8, 12, 24 and at the days of 2,3, 4, 7, 10 and 14. After the last blood sampling at 14th day, these groups were (n = 14) slaughtered for tissue sampling. The tissue samples were taken from tail fat, subcutaneous fat, heart and liver. Blood sampling continued for the remained members of i.m, treatment (n = 5) at the days of 21, 28 and 35. Blood plasma and the tissue samples examined for vitamin E (alpha-tocopherol) and vitamin A (retinol) concentrations using HPLC. The results showed that oral administration increased vitamin E concentrations. The increase observed at the hour 4 and the maximum values determined between 8 _ 24 hours. The values began to decrease after 2nd day (P0.05). Intramuscular administration could not increase the concentrations of vitamin E in blood plasma (P0.05). Oral administration on the 3rd day increased vitamin E content in blood plasma and heart (PO.OOI), the liver (PO.Ol), and in subcutaneous fat (PO.05). Oral and i.m. administration caused an increase in the concentration of vitamin E in the heart and liver (PO.OOl), subcutanous fat (PO.Ol), tail fat (PO.05), on the 14th day after treatment. Oral administration improved vitamin A content of subcutaneous fat on the 3rd day (PO.05). At the 14th day after i.m. administration, vitamin A content of tail fat and subcutanous fat (PO.Ol) also improved. It can be concluded that oral administration of vitamin E rapidly increases its concentration in blood plasma and keeps the contents high in the tissues within 2 weeks; intramuscular administration of vitamin E does not increase its concentration in blood plasma however, provides higher content of the vitamin in the tissues; oral administration is a suitable mean when an animal is fronted with a serious deficiency; it seems that both administrations of vitamin E, impove vitamin A content in the tissues, showing a "spare effect" as reported for liver and subcutaneuos being more active for absorbing vitamin E than tail fat tissue. It also seems that tail fat showes to be mostly a storage site.