Leptin and Leptin Receptor Are Expressed in the Human Endometrium and Endometrial Leptin Secretion Is Regulated by the Human Blastocyst1

Embryonic implantation is a crucial event for the human reproductive function. Cytokines and paracrine molecules have been proposed as putative local regulators of this process. The leptin or the OB protein has been linked to the reproductive function and inflammatory response. In the present study, we describe for the first time the expression of leptin and leptin receptor (long form) in the secretory endometrium and that endometrial leptin secretion is regulated in vitro by the human blastocyst. Leptin and leptin receptor messenger RNA and protein were identified in secretory endometrium and in cultured endometrial epithelial cells (EECs) by RT-PCR, Western blot, and immunohistochemistry.…