Formation and release of secretory granules during mitosis in the anterior pituitary gland.

Kurosumi, Kazumasa

doi:10.1679/aohc1950.42.481

Cited by 13 publications

(3 citation statements)

References 11 publications

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“…Still a further possibility is that the responsiveness of the hypothalamo-pituitary glands to sex steroids is low until 30 days of age in our rats. With regard to the last possibility, there was a report suggesting that some maturational period was necessary until the estrogenic control on prolactin secretion became substantially effective [Ojeda and McCann, 1974;Ojeda et al, 1977], Mitotic prolactin cells were previously reported in estrogen-treated rats [Zam brano and Deis, 1970] or in intact adult rats [Kurosumi, 1971[Kurosumi, , 1979. The present study on developing pituitaries also showed the presence of mitotic prolactin cells, and that mitotic prolactin cells were more numerous in female rats than in males at adult ages.…”

Section: Discussionsupporting

confidence: 65%

Age-Related Changes in Prolactin Cell Percentage and Serum Prolactin Levels in Intact and Neonatally Gonadectomized Male and Female Rats

Takahashi¹,

Kawashima²

1982

Cells Tissues Organs

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Electron microscopically the percentages of various pituitary cell types were calculated at 30 and 90 days of age. Prolactin cell percentage was more at 90 days of age than at 30 days in both intact male and female rats. No sexual difference was observed in the percentage of prolactin cells at 30 days of age, but at 90 days female pituitaries contained more numerous prolactin cells than male ones. Neonatal ovariectomy did not affect the prolactin cell percentage at 30 days of age, while it lowered the percentage at 90 days. Neonatal orchidectomy did not affect the prolactin cell percentage at both 30 and 90 days of age. Mitotic prolactin cells were more frequently observed in intact female rats at estrus than in intact male rats at 90 days of age. These results show the presence of the sexual difference in the proliferation of prolactin cells. Serum prolactin levels increased with age in intact male and female rats. In neonatall·y gonadectomized male and female rats the serum prolactin levels failed to increase at 60 and 90 days of age. In general conclusion, the changes in serum prolactin levels are in line with the changes in prolactin cell population during postnatal development.

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Section: Discussionsupporting

confidence: 65%

Age-Related Changes in Prolactin Cell Percentage and Serum Prolactin Levels in Intact and Neonatally Gonadectomized Male and Female Rats

Takahashi¹,

Kawashima²

1982

Cells Tissues Organs

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“…Before electron-microscopic immunocytochemistry became routine, Kurosumi et al (Kurosumi and Kobayashi 1966;Kurosumi 1971Kurosumi , 1979) observed mitosis of pituitary cells, whose cytoplasm contained many secretory granules, in the rats after removal of the target organ or in female rats during estrus.…”

Section: Studies On the Proliferation Of Pituitary Cells Identified Bmentioning

confidence: 99%

Proliferation and differentiation of rat anterior pituitary cells

Taniguchi

Yasutaka

Kominami

et al. 2002

Anatomy and Embryology

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Studies on the proliferation and differentiation of the cells in the rat anterior pituitary were reviewed. The mitotic rate of anterior pituitary is low in the control adult animal, but it increased by stimulation, such as by ablation of the target organ. A high mitotic rate was also reported during ontogenesis of the pituitary. Concomitant with this augmented mitosis, the number of those cells that are double-labeled with the marker of proliferation and the antibody to pituitary hormones increased as well. The percentage of these double-labeled cells in all the proliferating cells is less than 10%, suggesting that about 1/10 of the proliferating cells are involved in producing pituitary cells. This percentage for GH cells is 30-40% at most, suggesting very active production of them. The percentage of the double-labeled cell in all the hormone-producing cells is within 10% in all cell-types of the pituitary, including GH cells. When the proliferation is detected by a more sensitive method, this percentage increased to 20-40%, suggesting that the self-mitosis of the pituitary cells contributes considerably to their proliferation at a certain period during their ontogenesis.

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“…A further study by electron microscopy (Kurosumi, 1979) demonstrated not only the production of secretory granules but also the release of granules by exocytosis during mitosis (Fig. 5e,f).…”

Section: Lysosome Multivesicular Bodymentioning

confidence: 73%

Ultrastructural immunocytochemistry of the adenohypophysis in the rat: A review

Kurosumi

1991

J. Elec. Microsc. Tech.

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Immunocytochemistry has made great strides in the morphology of endocrine glands, especially the adenohypophysis, because the localization of hormones can be clearly demonstrated by this method in the microscopic preparations both for light and electron microscopy. In the adenohypophysis, electron microscopic immunocytochemistry is useful for identifying the producer cell of each hormone. The second contribution is its application to the cell biology of secretion mechanisms. The pituitary hormones, their precursors, derivatives, and fragments were artificially synthesized and their antibodies were produced. Using these antibodies the intracellular sites of synthesis, condensation, processing, and sorting were studied under the electron microscope. The ultrastructure of each cell organelle and its alteration due to the changing function was studied. It was proved that the intracisternal granules in the thyroidectomy cells contain thyroid-stimulating hormone (TSH). The trans-Golgi network or GERL contains a peculiar supporting structure, intracisternal skeleton. Transport of secretory granules may be performed in relation to the microtubules, actin, and some related substances. The most frequently observed mode of hormone release in the adenohypophysis is exocytosis. Sometimes multigranular exocytosis occurs. Vesiculation of membrane around the secretory granules often occur inward or outward. The inward vesiculation forms pinocytotic vesicles, through which the membrane material may be retrieved. The outward vesiculation forms vesicle-like fragments of cytoplasm being discarded to the extracellular space. By these mechanisms the surface area of the cell is maintained constantly.

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Formation and release of secretory granules during mitosis in the anterior pituitary gland.

Cited by 13 publications

References 11 publications

Age-Related Changes in Prolactin Cell Percentage and Serum Prolactin Levels in Intact and Neonatally Gonadectomized Male and Female Rats

Age-Related Changes in Prolactin Cell Percentage and Serum Prolactin Levels in Intact and Neonatally Gonadectomized Male and Female Rats

Proliferation and differentiation of rat anterior pituitary cells

Ultrastructural immunocytochemistry of the adenohypophysis in the rat: A review

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