Effect of insulin on IGFBP-1 and IGFBP-2 at day 10 post-ovulation. The effect of insulin (+/- Ins) on IGFBP-1 (BP-1) and IGFBP-2 (BP-2) secretion in culture media taken from endometrial explants (n = 2) at day 10 post-ovulation. Media samples were analysed after 24 h (D-1) and 48 h (D-2) incubation by western blotting for IGFBP-1 (A) and IGFBP-2 (B), and by ELISA for IGFBP-1 (C). Values above each band in A and B represent their optical density. PF: Proteolytic fragment of IGFBP-1. Open and closed bars in C represent IGFBP-1 levels released by explants from two different animals in the absence of insulin.