GHRL and polycythemia: In our previous study, it was indicated that ghrelin inducessevere polycythemia in the rats living in hypoxia (21).In a complementary study, the relation between ghrelinadministration and erythropoietin production has beenelucidated and we concluded that the polycythemic effectof ghrelin was not through erythropoietin upregulation(22).