Luteinizing hormone (LH) is secreted from the brain (pituitary) in sexually intact dogs to stimulate synthesis of estrogen and testosterone in females and males, respectively. However, LH is secreted at concentrations up to 20 times higher following gonad removal with spaying or castration because hormonal negative feedback is lost. Although LH is considered to be a reproductive hormone, there are dozens of non-reproductive tissues in dogs that contain receptors for LH including immune system cells, specifically lymphocytes.
Lymphoma is a common malignant cancer of dogs involving lymphocytes, and spayed/castrated dogs are reportedly 3-4 times more likely to develop lymphoma. Conventional chemotherapy results in remission in approximately 60-90% of cases with a median survival time of 6-12 months. Preliminary work has identified LH receptors in canine lymphoma tissue and demonstrated LH- receptor-induced proliferation of neoplastic lymphocytes in vitro.
This study aims to determine if LH receptor activation induces adhesion and migration of neoplastic lymphocytes in vitro. Characterizing the role of LH receptor in neoplastic lymphocyte proliferation may help guide future lymphoma treatment options.
Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02751-A
Michelle Kutzler, DVM, PhD; Oregon State University