Luteinizing hormone-releasing hormone neurons in XXXX preoptic/hypothalamus: differential intraneuronal localization of immunoreactive forms.

@entity1 @entity1893
Luteinizing hormone-releasing hormone (LRH) may be synthesized as part of a larger prohormone, as are several other neuropeptides. In this study, we sought not only to define the distribution and morphological characteristics of LRH neurons within the @entity1 preoptic area and hypothalamus, but also to identify sites of initial synthesis, posttranslational conversion to the decapeptide, and storage of LRH in these neurons. Immunoreactive molecular forms were differentiated using a series of antisera with distinct specificities in the peroxidase-antiperoxidase technique. These antisera were capable of detecting the fully processed hormone as well as extended decapeptide sequences. Immunopositive LRH neurons were more abundant in the infundibular area of the hypothalamus than in the preoptic area. Numbers of immunopositive perikarya and subcellular distribution of reaction product varied with binding requirements of the antisera. After treatment with an antiserum that requires the fully processed decapeptide for binding, the reaction product was associated almost entirely with granules in perikarya and processes, while very little was associated with either @entity1893 ( @entity1893 ) or Golgi apparatus. In contrast, with an antiserum capable of detecting extended forms of the decapeptide, the @entity1893 and Golgi were labeled in addition to granules. From these data, we infer that in @entity1 , mature decapeptide is present in granules within LRH neuronal perikarya and processes. Furthermore, the molecular forms associated with @entity1893 and Golgi may be precursors in which the decapeptide sequence is extended.
