Figure 6.

Schematic drawing of the proposed events leading to pituitary LH hypersecretion in prenatal T-treated sheep. Adult sheep prenatally exposed to T excess manifest reduced insulin sensitivity in the liver and skeletal muscle resulting in peripheral insulin resistance and compensatory hyperinsulinemia. In turn, increased circulating concentrations of insulin stimulate the anterior pituitary (AP), which remains insulin sensitive, to synthesize and secrete large amounts of LH. Although the exact mechanisms by which insulin promotes LH hypersecretion in prenatal T-treated sheep remain unclear, a reduction in ERα levels in the AP appears to be involved.