Light- and electron-microscopic immunocytochemistry and lectin histochemistry of the subcommissural organ: evidence for processing of the secretory material.
The subcommissural organ (SCO) of the rat was investigated by use of histochemical and immunocytochemical methods at the light- and electron-microscopic levels. Consecutive thin methacrylate sections were stained with the pseudoisocyanin (Psi), immunoperoxidase (IMC; employing an antiserum against Reissner's fiber, AFRU), periodic acid-Schiff (PAS) and periodic acid-silver methenamine (SM) techniques, and reacted with six types of lectins. Psi, SM, concanavalin A (Con A) and IMC were also used for double and triple sequential staining of the same section. Increasing dilutions of AFRU (from 1:1000 to 1:200 000) were used for immunostaining of serial paraffin sections. In addition, ultrastructural localization of (i) Con A-binding sites and (ii) immunoreactive secretory material was performed. Some of these procedures were also applied to the ophidian and canine SCO. Con A-positive, Psi-positive and immunoreactive materials coexisted within the same cisternae of the rough endoplasmic reticulum. The Golgi apparatus lacked Con A-positive and immunoreactive substances. Apical secretory granules and secreted material lying on the surface of the SCO showed (i) the highest affinity for AFRU, but were (ii) Con A-negative, and (iii) wheat-germ agglutinin-, PAS- and SM-positive. Reissner's fiber displayed a low affinity for AFRU. It is suggested that the SCO secretes N-linked glycoproteins, the carbohydrate and protein moieties of which undergo (i) a maturation process before being released, and (ii) some kind of modification(s) after their release into the ventricle. The perivascular secretory cells of the dog SCO might secrete a material different from that secreted by the ependymal cells.
E M
EM
Rodríguez
H
H
Herrera
B
B
Peruzzo
S
S
Rodríguez
S
S
Hein
A
A
Oksche
D000818:Animals; D003208:Concanavalin A / Q000031:analogs & derivatives; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure*; D004285:Dogs; D006651:Histocytochemistry / Q000379:methods; D006735:Horseradish Peroxidase; D007106:Immune Sera; D007124:Immunoenzyme Techniques; D037102:Lectins; D008689:Methacrylates; D008709:Methenamine; D008854:Microscopy, Electron; D009490:Neurosecretory Systems / Q000378:metabolism*; D010503:Periodic Acid-Schiff Reaction; D011804:Quinolines; D051381:Rats; D011919:Rats, Inbred Strains; D012911:Snakes; D013194:Staining and Labeling / Q000379:methods; D013351:Subcommissural Organ / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure
D007106:Immune Sera; D037102:Lectins; D008689:Methacrylates; D011804:Quinolines; C045779:concanavalin A-horseradish peroxidase conjugate; D003208:Concanavalin A; C100254:pseudoisocyanine; D006735:Horseradish Peroxidase; D008709:Methenamine