HIF1A and placental insufficiency: These studies have consistently reported increased levels of HIF-1α mRNA in various models of placental insufficiency, including modified Reduced uterine perfusion pressure (RUPP) (created by ligation of the ovarian arteries only) in mice [30], L-NAME rats (treated with Nω-nitro-L-arginine methyl ester) [31], and rats on a low-sodium diet [32].