Histochemical, cytochemical and autoradiographic studies on the rostellum of Hymenolepis diminuta.

Histochemical studies on the rostellum of Hymenolepis diminuta revealed diastase-stable, protein/neutral carbohydrate-rich material localized in the rostellum tegument. The remainder of the rostellum, primarily composed of the glycogen-rich myocytons of the rostellum musculature, is protein-poor, but rich in diastase-labile, neutral and acidic carbohydrates. Ultrastructural cytochemical studies, using the periodic acid-thiocarbohydrazide osmium (PATCO) technique, indicated that the granules of the rostellar tegumental cytons and distal cytoplasm are carbohydrate-rich. Lipids are present in the rostellar myocytons but not in the tegumental cytons. Autoradiography using a pulse-labeling with [3H]leucine revealed an apical translocation of tegumental granules, but at a slower rat than had been reported for the strobilar tegument of the same organism. Neither [3H]galactose nor [3H]glucose were incorporated into the rostellar tegumental granules. The function of the secretory glycoprotein(s) produced in the rostellar tegument and its (their) possible role in the regulation of maturation and/or strobilization remain enigmatic.