CIRCULATING ALPHA-TOCOPHEROL FOLLOWING INTRAMUSCULAR OR ORAL VITAMIN-E ADMINISTRATION IN SWAINSONS HAWKS (BUTEO-SWAINSONII)

Alpha-tocopherol (alpha-TOC, as D-alpha-tocopherol) administered both intramuscularly (i.m.) and orally (p.o.) to a captive group of five Sw ainson's hawks (Buteo swainsonii) at doses of 15 or 30 mg/kg body mass resulted in markedly different serum responses. Neither i.m. dose sig nificantly altered serum concentrations within a week from an average baseline value of 28.4 +/- 3.2 mug/ml. A single p.o. dose (15 mg/kg bo dy mass) without food significantly increased circulating serum concen tration from 30.0 +/- 8.7 to 57.9 +/- 27.4 mug/ml by 192 hr; values pl ateaued at elevated levels for up to 62 days postadministration. This apparently represented serum saturation, as a subsequent oral dose of 30 mg/kg effected no changes in serum concentrations measured over 32 days. A suggested therapy for raptor patients suspected to be vitamin E deficient includes p.o. (15 mg/kg body mass) doses of alpha-TOC with out food, followed by dietary supplementation to maintain status.