Vascular endothelial growth factor and its receptors in male fertility Andreas Obermair, M.D., Andreas Obruca, M.D., Michaela Pöhl, M.D., Alexandra Kaider, Anja Vales, M.D., Sepp Leodolter, M.D., Johann Wojta, Ph.D., Wilfried Feichtinger, M.D.  Fertility and Sterility  Volume 72, Issue 2, Pages 269-275 (August 1999) DOI: 10.1016/S0015-0282(99)00234-4

Figure 1 Box plots for seminal vascular endothelial growth factor (VEGF) concentrations (ng/mL, log-transformed) in the subgroup of patients <37 years of age and in those ≥37. In patients <37 years, low seminal vascular endothelial growth factor values are associated with the chance of pregnancy, whereas higher values are associated with nonpregnancy. In patients ≥37 years, high seminal vascular endothelial growth factor values are associated with pregnancy, whereas low values are associated with nonpregnancy. The boundaries of the box represent the 25th and 75th percentiles. The line inside the box represents the median. The so-called whiskers are drawn from the edge of the box to the largest and smallest values that are outside the box within 1.5 box lengths. ∗ = values outside this range. No whiskers are shown where the value of the 25th percentile equals the minimum value. The median value is not shown where it equals the value of the 25th percentile. (□ = no pregnancy; ■ = pregnancy.) Fertil Steril ©1999 Fertility and Sterility 1999 72, 269-275DOI: (10.1016/S0015-0282(99)00234-4)

Figure 2 (A), FACS scan analysis revealed strong and distinct expression of Flk-1 and Flt-1. (B), Negative control of immunocytochemistry. (C), Staining for Flk-1 was largely positive around the base of the sperm flagella; (D), staining for Flt-1 was mainly positive in the acrosomal region. Arrows indicate the areas of most intense staining reaction. Fertil Steril ©1999 Fertility and Sterility 1999 72, 269-275DOI: (10.1016/S0015-0282(99)00234-4)