Leptin human has been used:to study the effect of leptin on ACAT1 (acyl-coenzyme A:cholesterol acyltransferase 1) expression and cholesterol efflux from primary cultured human macrophagesto study the effect of leptin on expression of IGFBP2 (insulin growth factor binding protein 2) in skeletal muscleto study the effect of leptin on HLA-G (human leukocyte antigen G) expression in placental trophoblaststo study the effect of leptin onin vitromaturation, fertilization and development of horse oocytes after ICSI (intracytoplasmic sperm injection)