Hum. Reprod. Advance Access originally published online on December 17, 2008
Human Reproduction 2009 24(3):705-709; doi:10.1093/humrep/den451
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Evaluation of Ki-67 antigen expression in the zona reticularis of the adrenal cortex of female rats in persistent estrus
1 Department of Gynecology, Federal University of Piauí, Teresina, Piauí, Brazil 2 School of Medicine, State University of Campinas, Campinas, São Paulo, Brazil
3 Correspondence address. Avenida Elias João Tajra, 1260, Bairro Jockey Club, 64059-300 Teresina, Piauí, Brazil. Tel: +55-86-3232-5063; Fax: +55-86-3215-0470; E-mail: beneditoborges{at}globo.com
BACKGROUND: Hyperandrogenism and chronic anovulation are basic characteristics of polycystic ovary syndrome (PCOS), and androgens from the adrenal glands play an important role in the hyperandrogenism. Our aim was to evaluate the proliferative activity in the zona reticularis cells of the adrenal cortex of female rats in persistent estrus, a model developed to mimic PCOS.
METHODS: Forty-four female Wistar–Hannover rats were randomly divided into two groups: control (n = 17) and animals which received 1.25 mg testosterone propionate s.c. on the second day of life (n = 27). At 90 days of age, after confirmation of persistent estrus, the animals were sacrificed, and the adrenal glands were removed and fixed in 10% buffered formalin to investigate Ki-67 antigen (marker of proliferation) expression by immunohistochemical analysis. Student's t-test and Levene's test were used in the statistical analysis.
RESULTS: The mean percentage of Ki-67-stained nuclei per 1000 cells in the zona reticularis of the adrenal cortex was 15.58 ± 1.14 (SEM) and 51.59 ± 1.81 in the control and persistent estrus animals, respectively (P < 0.001).
CONCLUSIONS: Proliferative activity in the zona reticularis cells of the adrenal cortex of the androgenized female rats was significantly greater than that of the control animals.
Key words: persistent estrus/rat/polycystic ovary/adrenal/Ki-67
Submitted on September 10, 2008; resubmitted on November 14, 2008; accepted on November 19, 2008.