Equine chorionic gonadotrophin improved vascularization of feline ovarian tissue xenografted into immunosuppressed mice

The objective of this study was to evaluate effects of eCG on vascularization and development of feline ovarian tissue xenografted to immunosuppressed mice. Feline ovarian fragments (∼1 mm3) were transplanted under the renal capsule of 20 adult, ovariectomized, C57BL/6 SCID female mice. At 45 d after transplantation, 10 mice (controls) were euthanized and the remainder given 10 IU of eCG (and sacrificed 48 h later). Transplants were recovered immediately after death, fixed, sectioned, and stained with periodic acid-Schiff (PAS). Fragment volume (Cavallieri principle) and vascularization were assessed. Mean xenotransplant volume for control and treatment groups was 0.17 ± 0.03 and 0.37 ± 0.13 mm3, respectively (P = 0.0952); vascular volume density, 30.3 ± 11.3 and 49.1 ± 8.9% (P = 0.0281); surface density, 4.1 ± 2.4 and 6.2 ± 1.7 μm−1 (P = 0.2222); and vessel total surface, 0.63 ± 0.24 μm2 and 2.28 ± 1.05 μm2 (P = 0.0079). In conclusion, eCG significantly increased vascular volume density of xenotransplanted ovarian tissue and improved its development.