Gonadotropin-releasing hormone agonist administration reduced vascular endothelial growth factor (VEGF), VEGF receptors, and vascular permeability of the ovaries of hyperstimulated rats.

Objective: Using hyperstimulated rats, to elucidate the mechanisms of gonadotropin-releasing hormone agonist (GnRH-a) treatment to prevent early ovarian hyperstimulation syndrome (OHSS).

Design: Descriptive study of hyperstimulated rats as an early OHSS model with Western blot analysis, Northern blot hybridization, and vascular permeability assay.

Setting: Experimental laboratory research.

Animal(s): Sprague-Dawley female rats were used for collecting ovarian samples.

Intervention(s): Hyperstimulated rats received consecutive GnRH-a treatment from the start of pregnant mare serum gonadotropin (PMSG) treatment through 2 days after hCG administration.

Main Outcome Measure(s): Expressions of vascular endothelial growth factor (VEGF), VEGF receptor-1 (VEGFR-1: Flt-1), VEGF receptor-2 (VEGFR-2: KDR/Flk-1), and vascular permeability by Evans blue leakage.

Result(s): GnRH-a treatment significantly reduced expressions of VEGF, VEGFR-1, and VEGFR-2 both in mRNA and protein levels in the ovaries of hyperstimulated rats. GnRH-a treatment also reduced vascular permeability in the ovaries of hyperstimulated rats.

Conclusion(s): It is speculated that GnRH-a treatment may prevent early OHSS by reducing vascular permeability through the decrease in VEGF and its receptors.