Effect of insulin on IGFBP-1 and IGFBP-2 at the implantation and non-implantation sites. The effect of insulin (+/- Ins) on IGFBP-1 (BP-1) and IGFBP-2 (BP-2) secretion in culture media taken from endometrial explants of the implantation and non-implantation sites of a day 32 pregnant baboon (n = 1). Media samples were analysed by western blotting for IGFBP-1 (A) and IGFBP-2 (B), and by ELISA for IGFBP-1 (C) after 24 h (D-1) and 48 h (D-2) incubation. Values above each band in A and B represent their optical density. PF: Proteolytic fragment of IGFBP-1. Open bars: + Insulin; Closed bars: - Insulin.