Immunohistochemical localization of transforming growth factor-alpha, epidermal growth factor (EGF), and EGF receptor in the human fetal ovary

Peptide growth factors are thought to be involved in adult ovarian regulatory functions. However, little is known about the role of growth factors in human fetal ovarian development. This study is an attempt to identify and localize transforming growth factor-alpha (TGF alpha), epidermal growth factor (EGF), and EGF receptor (EGF-R) in human fetal ovaries. Ovaries were obtained from first and second trimester elective abortuses. Immunohistochemistry was performed on paraffin sections of these specimens after fixation. We examined the sections microscopically using the specific antibodies against TGF alpha, EGF, and EGF-R. Phosphate-buffered saline and preimmune IgG were used as negative controls. First and second trimester ovaries stained positively for all three proteins. Staining was significantly more intense in the oocytes than in the stroma. Negative controls did not stain. These results combined with our previous demonstration of messenger ribonucleic acid for these growth factors suggest roles for TGF alpha, EGF, and EGF-R in human fetal ovarian development. The strong staining in the oocytes suggests a possible autocrine or paracrine role of these growth factors in human oocyte growth in, utero.