Doxycycline inhibits vascular leakage and prevents ovarian hyperstimulation syndrome (OHSS) in a murine model

Abstract

Gonadotropin-induced angiogenesis and capillary leakage play a key role in the pathogenesis of ovarian hyperstimulation syndrome (OHSS). Doxycycline has been reported to inhibit angiogenesis. Some angiogenesis inhibitors inhibit vascular leakage. We postulated that doxycycline would inhibit OHSS. Determining the effect of doxycycline on vascular leakage in a murine OHSS model. OHSS was induced in 4 week old C57Bl/6 female mice. Pregnant mare serum gonadotropin (PMSG) was administered intraperitoneally (20 IU/day) for three days and on day 4, human chorionic gonadotropin (HCG) (5 IU) was injected to induce ovulation. For the Miles vascular permeability assay, mice were anesthetized 48 hours after HCG, and 0.1 ml of 5 mM Evans Blue dye was injected intravenously. After thirty minutes, the peritoneal cavity was infused with 2 ml of 0.9% NaCl. Subsequently, the fluid was extracted and Evans Blue concentration was measured spectrophotometrically at 620 nm. Designated groups of mice were treated during hormone stimulation with daily oral doxycycline (10–80 mg/kg/day). Ascites volume was determined spectrophotometrically using dye dilution. Ovaries were weighed, sectioned and stained with H&E for morphology and corpus luteum formation, and stained with anti-CD31 antibody for blood microvessel density. Doxycycline inhibited peritoneal vascular permeability 2.5 fold (0.126 ± 0.069 vs. 0.311 ± 0.163 OD 620 nm, P=0.048) and ascites accumulation by 25% (307.9 ± 35.0 μL vs. 399.2 ± 16.6 μL, P=0.046) in PMSG stimulated mice when compared to PMSG alone. Notably, doxycycline decreased vascular permeability to levels observed in non-stimulated mice (0.126 ± 0.069 vs. 0.156 ± 0.054 OD 620 nm, P=0.46). Furthermore, doxycycline treatment did not inhibit ovarian stimulation or ovulation when compared to controls, as indicated by similar ovarian morphology, ovarian weights (25.7 ± 5.4 mg vs. 25.1 ± 2.5 mg, P=0.83) and corpus luteum counts (12.7 ± 3.2 vs.13.2 ± 3.0, P=0.81). Importantly, vessel density within the corpora lutea was similar in the two groups. Doxycycline effectively prevents OHSS in a murine model without compromising ovarian stimulation and consequent ovulation. This effect is most likely due to inhibition of vascular leakage. Its safety and implication in the prevention of human OHSS warrant further studies.