Neurotensin: A novel mediator of ovulation?

The midcycle luteinizing hormone (LH) surge initiates a cascade of events within the ovarian follicle which culminates in ovulation. Only mural granulosa cells and theca cells express large numbers of LH receptors, and LH-stimulated paracrine mediators communicate the ovulatory signal within the follicle. Recent reports identified the neuropeptide neurotensin (NTS) as a product of granulosa cells.

Neurotensin stimulates the sperm acrosome reaction and reduces percentages of fertilization in vitro.

Objective: To determine the impact of neurotensin (NTS), a naturally occurring peptide, on the function of human and nonhuman primate sperm.

Design: Experimental study.

Setting: University-based research laboratory.

Thrombospondin 1 (THBS1) Promotes Follicular Angiogenesis, Luteinization, and Ovulation in Primates.

Angiogenesis is essential to both ovulation and the formation of the corpus luteum. The thrombospondin (THBS) family of glycoproteins plays diverse roles in regulation of angiogenesis, but the role of these vascular regulators in ovulation and luteinization remain to be elucidated. Using the cynomolgus macaque as a model for human ovulation, we demonstrated that levels of THBS1 mRNA and protein in preovulatory follicle granulosa cells increased after the ovulatory gonadotropin surge, with peak levels just before the expected time of ovulation.