Effect of variation of trans-fatty acid in lactating rats' diet on lipoprotein lipase activity in mammary gland, liver, and adipose tissue.

Objective: Lactation is associated with an increase in lipoprotein lipase (LPL) activity in the mammary gland (MG) and a decrease in adipose tissue because lactation redirects circulating substrates to the MG for milk synthesis. We investigated the effects of different dietary contents of trans-fatty acid (TFA) on LPL activity in maternal tissues and fatty acid composition in milk.

Methods: Lactating rats were fed semisynthetic isocaloric diets containing 7% soy oil (control), 7% partially hydrogenated vegetable oil (7%-PHVO), 5% PHVO plus 2% soy oil (5%-PHVO), or 3.