Dietary vitamin a (VIT A) affects vit a content of mammary glands in rats

Because of a lack of information on the VIT A content of mammary glands and our interest in the potential for increased delivery of chylomicron VIT A to mammary glands during lactation, we performed a pilot study on the effects of VIT A intake and reproductive state on mammary gland VIT A content. Weanling female Sprague-Dawley rats were fed a purified diet containing 10 nmol VIT A/g diet until sexual maturity. Rats were mated and then fed either 0 or 50 nmol VIT A/g diet. Age-matched, non-mated rats were also fed 0 or 50 nmol VIT A/g diet. Following parturition, pups nursed for 15 d; maternal plasma and milk samples were collected on d 2, 5, 10, and 15 of lactation. On d 15, rats were killed, and liver and mammary glands were removed. Mammary glands and milk were analyzed for VIT A and lactose, plasma and liver for VIT A. Intake had a variable, nonsignificant effect on mammary gland VIT A content in non-lactating rats (4.2 + 1.0 [mean±SD, n=3] vs 18.2±11.2 [n=4] nmol) at 0 and 50 nmol/g, respectively. Lactation had no significant effect at 0 nmol/g intake (9.1 ±5.2 nmol [n=5]) but high (50 nmol/g) VIT A intake and lactation caused a significant increase in mammary gland VIT A content (43.0+13.0 nmol [n=3]) when compared with the other 3 groups.