Hum. Reprod. Advance Access originally published online on January 4, 2007
Human Reproduction 2007 22(4):1003-1010; doi:10.1093/humrep/del466
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Amelioration of insulin resistance in women with PCOS via reduced insulin receptor substrate-1 Ser312 phosphorylation following laparoscopic ovarian electrocautery
1 Department of Obstetrics and Gynecology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 2 Institute of Clinical Medicine 3 Institute of Physiology, National Yang-Ming University 4 Department of Medical Research & Education 5 Department of Internal Medicine, Taipei Veterans General Hospital 6 School of Medicine, Fu-Jen Catholic University, Taipei Hsien 7 Department of Obstetrics and Gynecology, Taipei Medical University, Taipei, Taiwan
8 To whom correspondence should be addressed at: Department of Medical Research and Education, Taipei Veteran General Hospital, No 201, Shih-Pai Road, Taipei, Taiwan. E-mail: ltho{at}vghtpe.gov.tw
BACKGROUND: Increased Ser312 phosphorylation of insulin receptor substrate (IRS)-1 is one possible molecular mechanism of insulin resistance in polycystic ovary syndrome (PCOS). We investigated whether laparoscopic ovarian electrocautery (LOE) improved insulin sensitivity in women with PCOS and examined the underlying molecular mechanism of LOE.
METHODS: Adipose tissue and blood samples from 12 women with PCOS before, and 3 months after, LOE were analysed.
RESULTS: Before LOE, women with PCOS were found to have significantly higher 2 h glucose, fasting and 2 h insulin levels, homeostasis model insulin resistance index and lower fasting glucose-to-insulin ratio (G0/I0) than healthy, lean, age-matched controls. Serum levels of glucose and insulin were significantly decreased, and G0/I0 ratio was significantly increased 3 months after LOE. Levels of activated extracellular signal-regulated kinase 1/2 in PCOS women were higher than in controls, but were significantly decreased after LOE. Levels of insulin receptor, glucose transporter-4 and phosphatidylinositol 3-kinase were lower in PCOS patients before LOE than in controls and increased after LOE. Levels of Ser312-phosphorylated IRS-1 in PCOS women before LOE were higher than in controls and decreased significantly after LOE, whereas IRS-1 tyrosine phosphorylation in PCOS women before LOE was lower than in controls and increased significantly after LOE.
CONCLUSION: Over the short observation period of this study, our results demonstrated that LOE effectively ameliorated insulin resistance in women with PCOS via decreased IRS-1 Ser312 phosphorylation.
Key words: extracellular signal-regulated kinase/laparoscopic ovarian electrocautery/phosphatidylinositol 3-kinase/serine phosphorylation
Submitted on June 18, 2006; resubmitted on June 18, 2006; accepted on November 7, 2006.