Immunohistochemical Localization of Luteinizing Hormone-Releasing Hormone in the Rat Median Eminence

Abstract

Although it has been shown thathypothalamic neurohormones controlling adenohypophysealactivity are concentrated in the medianeminence, precise identification of the intracellularstructures containing hypophysiotropic hormoneshas not been achieved. Using an immunohistochemicaltechnique at the electron microscopiclevel, we have observed that luteinizinghormone-releasing hormone (LH-RH), the neurohormonestimulating the release of both FSHand LH, is contained in the secretory granules of somenerve endings located in the palisade layer of themedian eminence. This is the first demonstration atthe ultrastructural level that an hypothalamicreleasinghormone is stored in secretory granules ofthe median eminence. (Endocrinology95:314, 1974)