Immunohistochemical localization of prolactin receptor in human digestive tissues
Prolactin (PRL) is primarily recognized for its lactogenic effect. However, it is known that this polypeptide hormone exerts a great variety of biological functions acting on reproduction, osmoregulation, growth, metabolism, immunomodulation and even on behavior. The actions of PRL initiate with hormone binding to a specific cell surface receptor that belongs to the cytokine/GH/PRL receptor family or the hematopoietin receptor family The PRLR is widely distributed in numerous tissues. The aim of the present work was to investigate by immunohistochemistry the cellular distribution of PRLR in the human gastrointestinal tract and associated glands (liver and pancreas).Samples of normal esophagus, stomach, small and large intestine, liver and pancreas were obtained from surgical pieces or recent autopsies. These samples were immersion-fixed in 10% buffered formalin for 24 hr, dehydrated and embedded in paraffin routinely. B6.2 anti-PRLR and avidin-biotin-peroxidase complex (ABC) procedure were employed. The B6.2 mouse monoclonal antibody (prepared against a membrane enriched fraction of human metastatic breast cancer), was generously provided by Dr. Barbara K. Vonderhaar and used at a dilution of 1:250, for 1 hr.