title: beta-Endorphin is contained within presumptive receptosomes and lysosomes of the myenteric plexus of the rat.
abstract: Using the microdissection technique combined with the pre-embedding immunostaining method, beta-endorphin immunoreactivity (beta-END-IR) was noted within ring-shaped elements lying singly or in groups in nerve processes of the duodenal myenteric plexus of the rat. The beta-END-IR was noted as a strongly electron-dense precipitate rim on the inner surface of these elements. The membrane of the ring-shaped element as well as the beta-END precipitate rim were strikingly often unilaterally interrupted at the same site. Some of the ring-shaped beta-END-positive elements were noted within large osmiophilic bodies. The beta-END immunoreactive ring structure was 60-300 nm in diameter and possessed an empty electron-lucent space as well as a thin electron-dense membrane. The osmiophilic bodies were pleormorph, had a mean diameter of 250 nm and revealed thick electron-opaque membranes. Their inner spaces were homogenously filled with electron-dense materials. These findings might indicate that the beta-END-IR-containing ring-shaped elements represent receptosomes and that the pleomorph osmiophilic bodies are identical to lysosomes.
mesh_terms: D000818:Animals; D003594:Cytoplasmic Granules / Q000032:analysis*; D004723:Endorphins / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008247:Lysosomes / Q000032:analysis*; D008297:Male; D008854:Microscopy, Electron; D009197:Myenteric Plexus / Q000032:analysis* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D001615:beta-Endorphin