Angiogenin is involved in morphological changes and angiogenesis in the ovary

Angiogenin is a potent angiogenic factor secreted by cultured tumor cells and is found in various normal organs and tissues. The ovary is one of the adult organs in which angiogenesis normally occurs during the female reproductive cycle. In this study, we examined whether angiogenin protein is localized and if angiogenin mRNA is expressed in the normal bovine ovary by immunohistochemistry using polyclonal rabbit anti-bovine angiogenin IgG and by in situ hybridization using bovine angiogenin probe, respectively. The localization and mRNA expression of angiogenin in the ovarian follicle and in the corpus luteum were different in their developmental stages. The intensities of immunoreactivities and angiogenin transcripts in the follicle increased from the primordial to the tertiary (or Graafian) follicle. The early corpus luteum contained strong immunoreactivities and mRNA expression of angiogenin but these intensities weakened during regression. The results suggest that angiogenin is involved in morphological changes and angiogenesis in the ovary.