Expression analysis of StAR gene in rats with polycystic ovarian syndrome and hypothyroidism induced by PTU
Expression analysis of StAR gene in rats with polycystic ovarian syndrome and hypothyroidism induced by PTU
Sara Khodabandeh,1,*Homayoun Khazali,2Vahid Azizi,3abdolkarim hosseini,4
1. Faculty of Life Sciences and Biotechnology, Shahid Beheshti University 2. Faculty of Life Sciences and Biotechnology, Shahid Beheshti University 3. Faculty of Life Sciences and Biotechnology, Shahid Beheshti University 4. Faculty of Life Sciences and Biotechnology, Shahid Beheshti University
Introduction: Thyroid disorders and polycystic ovarian syndrome(PCOS) are two of the most common endocrine disorders. Although their pathophysiology are different, but they have similar features; for instance, they both show increase size of ovary and cystic appearance of ovary.
PCOS is the most common cause of infertility in reproductive age women. Early diagnosis can help avoid the aggravation of PCOS. Gynecologist can tell PCOS from the symptom description by the patients (such as the history of oligomenorrhea), and morphological features (hirsutism). However, PCOS diagnosis is based on some pre-defined criteria. In 1990, a conference convened by National Institutes of Health (NIH) defined the signs and symptoms of PCOS, which served as the original diagnostic criteria. Rotterdam consensus workshop held in 2003 characterized hyperandrogenism, menstrual irregularities and insulin resistance as the key features of PCOS. Blood pressure, cycle duration, follicle count, mean ovarian volume, SHBG, testosterone, FSH and prolactin can indicate PCOS.
Thyroid disorders are the most common endocrine problems in women. Among various thyroid disorders, the prevalence of hypothyroidism is more with about 4%–5% worldwide. Females are at more risk of developing hypothyroidism than males. Undiagnosed and untreated thyroid disease can be a cause for infertility as well as sub-fertility. Thyroid dysfunction can affect fertility in various ways resulting in anovulatory cycles, luteal phase defect, high prolactin (PRL) levels, and sex hormone imbalances.
There are researches that indicate how PCOS women can get hypothyroidism and also some researches show how hypothyroidism can cause PCOS. Nevertheless it is not clear how these two diseases can affect each other which is the aim of this study.
Methods: 25 female wistar rats were divided into 5 groups (n=5): 1)control, 2)PCOS group, 3)PCOS + PTU1, 4)PCOS+ PTU2, 5)PCOS+PTU4. PCOS was induced with estradiol valerate (2mg/kg). after 30 days groups 3 , 4 and 5 were feed with 1 , 2 and 4 mg/kg propylthiouracil for 7 days. After that both ovaries were isolated for measurement of StAR gene expression. Data were analyzed by Graph Pad Prism8 software and appropriate tests.
Results: qRT-PCR results showed StAR expression was significantly higher in PCOS group than control Group and also its expression was significantly lower in PTU groups that received 2 and 4 mg/Kg than PCOS group.
Conclusion: Disruption of StAR expression is the causative factor that effect steroidogenesis. Since measurement of steroid hormones is one of the way for diagnosis of PCOS , so occurrence of both hypothyroidism and PCOS make it harder to diagnose PCOS and following that it would be harder to deal with these diseases.