Plasma Concentration and Uterine and Ovarian Expressions of Insulin-Like Growth Factor-2 in Dogs with Cystic Endometrial Hyperplasia-Pyometra

Abstract

The objective of this study was to investigate the plasma concentrations of insulin-like growth factor-2 (IGF-2) as well as its expression in the uterus and ovary of healthy dogs and those with cystic endometrial hyperplasia (CEH)-pyometra complex. Group 1 (n = 10) included bitches with open cervix pyometra, while Group 2 (n = 7) consisted of clinically healthy bitches in dioestrus. The number of IGF-2 immunopositive interstitial cells was significantly higher in Group 1, whereas in Group 2 there were only two cases in which a few cells were IGF-2 immunopositive. 1GF-2 immunopositivity was observed in the endometrial glandular epithelium in both groups. Additionally, interstitial fibroblasts and macrophages in the endometrium were also positive in Group 1. The concentration of plasma IGF2 was higher in Group 1 than in Group 2 (P < 0.05). The concentration was positively correlated with IGF-2 expression in the endometrial glands (r = 0.926; P < 0.001) in Group 1. However, a negative correlation was present between plasma IGF-2 concentration and IGF-2 expression in the interstitial endocrine cells of the ovary in Group 1 (r = 0.652; P < 0.05). The results suggest that IGF-2 plays an important role during the inflammatory process occurring in bitches with CEH-pyometra complex as well as in the endometrium of healthy bitches in dioestrus.