ISSN:
1432-0568
Keywords:
Corticotrophs
;
Pituitary gland
;
Golden hamster
;
Immunocytochemistry
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The ultrastructure of corticotrophs in the pituitary of golden hamsters was studied by immunocytochemistry. Corticotrophs were classified into three types according to the different size of the secretory granules. Type A and B cells were oval or polygonal in shape containing small (158±38 nm) and medium-sized (250±53 nm) secretory granules, respectively. Type C cells were usually pyramidal or irregular in shape, and contained large secretory granules (380±78 nm). The cytoplasmic organelles of type B and C cells were fairly well developed. In all types of corticotrophs, the secretory granules varied in electron density, and were either arranged in a single row along the cell membrane, or concentrated in the vascular pole of the cytoplasm. Many of the corticotrophs sent processes to encircle neighboring somatotrophs. In the female, the proportions of type A and B cells were higher then those in the male, whereas that of the type C cells was lower. All three types of corticotrophs were observed in the early postnatal stage. The population of type A cells decreased with the advancement of postnatal development, with a concomitant increase of that of the type C cells. Thus, type A cells might represent the immature type of corticotrophs which would evolve to become the type C cells. One to 2 weeks after adrenalectomy, the number of type C cells was drastically increased. This was accompanied by their prominent changes in ultrastructure as in the type B cells. The cytoplasm became hypertrophic with extensive dilated cisternae of rough endoplasmic reticulum. The large Golgi apparatus displayed profiles seemingly involved in the formation of secretory granules. The number of type A cells was moderately decreased, and they showed little morphological alteration. Since type B and C corticotrophs exhibited a remarkable response to adrenalectomy, it is concluded that they represent the active state of corticotrophs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00186460
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