LEPTIN RECEPTOR IMMUNOREACTIVITY IS ASSOCIATED WITH THE GOLGI-APPARATUS OF HYPOTHALAMIC NEURONS AND GLIAL-CELLS

Leptin has emerged as a major peripheral hormone, controlling central mechanisms of metabolism and related autonomic and endocrine functions . In the regulation of hypothalamic neurones, leptin is suggested to a ffect different second messenger systems and transcription regulating factors. The present study reports the predominant localization of lep tin receptor immunoreactivity in the cis and trans cisternae of the Go lgi apparatus in hypothalamic neuronal and glial cells. In these hypot halamic cells, translocation of leptin receptor immunoreactivity from the Golgi apparatus to the perikaryal membrane, nucleus or to the cyto plasm was not apparent after manipulation of the metabolic state eithe r by fasting or suppression of the thyroid axis. On the other hand, le ptin receptor immunoreactivity was associated with the perikaryal memb rane of neurones in other parts of the central nervous system, includi ng the dentate gyrus and the cingulate cortex. These data indicate an extremely high turnover of leptin receptors in hypothalamic target sit es, but also raise the possibility that leptin may interact with the G olgi apparatus-related mechanisms to alter intracellular mechanisms.