Autoradiographic localization of leptin binding in the choroid plexus of ob/ob and db/db mice

The obese gene product, leptin, is synthesized in adipose tissue and is a circulating factor regulating body weight. To identify the location of leptin receptors in the brain we have performed an autoradiographic study of the binding of [¹²⁵I]leptin to frozen sections of mouse brain. Dense specific binding of [¹²⁵I]leptin was found only in the choroid plexus which is located in the dorsal part of the third ventricle and lateral ventricles. Specific binding of [¹²⁵I]leptin was found in the ob/ob and db/db mice. These findings further our understanding of the sites and mechanism of action of leptin on brain centers regulating body weight.