Metformin: Direct Inhibition of Rat Ovarian Theca-Interstitial Cell Proliferation

Metformin activates adenosine monophosphate–activated protein kinase (AMPK) in rat ovarian thecainterstitial cells and subsequently inhibits cell proliferation and insulin-induced mitogenic signaling pathways.


Matthew A. Will, M.D., Murugesan Palaniappan, Ph.D., Helle Peegel, M.S., Pradeep Kayampilly, Ph.D., K.M.J. Menon, Ph.D.

Vol 98, Issue 1, Pages 207-214



To determine whether metformin has direct effects on ovarian theca-interstitial (T-I) cell proliferation through activation of adenosine monophosphate–activated protein kinase (AMPK).


In vitro experimental study.


Academic medical center laboratory.


Immature Sprague-Dawley female rats.


Ovarian T-I cells were isolated, purified, and cultured in the absence (control) or presence of insulin (1 μg/mL) with or without metformin or other activators/inhibitors of AMPK (AICAR, compound C).

Main Outcome Measure(s):

Proliferation assessed by determination of expression levels of proteins involved in cell cycle progression, cyclin D3, and cyclin-dependent kinase 4 (CDK4) with Western blot analysis, and determination of DNA synthesis with bromodeoxyuridine (BrdU) incorporation assay; activation of AMPK, Erk1/2, and S6K1 determined by Western blot analysis with the use of antibodies specific for the phosphorylated (activated) forms.


Metformin inhibited insulin-induced ovarian T-I cell proliferation and the up-regulation of the cell cycle regulatory proteins, cyclin D3 and CDK4. Metformin independently activated AMPK in a dose-dependent manner. Treatment with metformin inhibited insulin-induced activation of Erk1/2 and S6K1. This effect was reversed with the addition of compound C, a known AMPK inhibitor.


Metformin directly inhibits proliferation of ovarian T-I cells via an AMPK-dependent mechanism. These findings further validate the potential benefits of metformin in the treatment of conditions associated with hyperinsulinemia and excessive growth of ovarian T-I cells (such as polycystic ovary syndrome).

Read the full text at:

Please sign in or register for FREE

Your Fertility and Sterility Dialog login information is not the same as your ASRM or EES credentials. Users must create a separate account to comment or interact on the Dialog.