Mitoses of existing corticotrophs contribute to their proliferation in the rat pituitary during the late fetal period

Taniguchi, Y.; Kominami, Rieko; Yasutaka, Satoru; Shinohara, Harumichi

doi:10.1007/s004290000140

Cited by 18 publications

(15 citation statements)

References 11 publications

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“…Although several studies supported the usefulness of PCNA as a marker of proliferating cells (Nakane et al 1989;Landberg and Roos 1991;Yamada et al 1992;Nakajima et al 1994;Sasaki et al 1994;Ezaki and Matsuno 1995), some authors pointed out that the expression of PCNA is not restricted to the S phase of the cell cycle and the results obtained should be interpreted with caution (Coltrera and Gown 1991;Connolly and Bogdanffy 1993;Linden et al 1993;Elsasser et al 1994;Atkin et al 1997). Oishi et al (1993) and Taniguchi et al (2001a) applied this method to the proliferation of rat pituitary cells in control adults and in the fetus, showing that PCNA can be used as a sensitive marker of cell proliferation (see below).…”

Section: Methods Used To Detect Cell Mitosismentioning

confidence: 92%

“…In an attempt to detect proliferating cells more efficiently, we used BrdU injections twice at an interval of 10 h, or used immunocytochemical detection of PCNA instead of BrdU (Taniguchi et al 2001a), and studied the proliferation at the periods when the percentage of double-labeled cells is at the peak: E19.5 for the ACTH cells and P3-P10 for the other cell types. By these means the BrdU-or PCNA-labeled cells increased 1.3 to 2.0 or 2.4 to 4.5-fold, respectively, compared with the single BrdU injection (Fig.…”

Section: Proliferation Of Rat Pituitary Cells During Ontogenesismentioning

confidence: 99%

“…Gulyás et al (1993) reported the postnatal development of ACTH, GH and PRL cells in female rats using [ 3 H]dT autoradiography and immunocytochemistry. We have studied quantitatively the development of the pituitary through fetal and postnatal periods using the BrdU method combined with immunocytochemistry (Taniguchi et al 2000(Taniguchi et al , 2001a(Taniguchi et al , 2001b(Taniguchi et al , 2001c.…”

Section: Proliferation Of Rat Pituitary Cells During Ontogenesismentioning

confidence: 99%

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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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Section: Methods Used To Detect Cell Mitosismentioning

confidence: 92%

Section: Proliferation Of Rat Pituitary Cells During Ontogenesismentioning

confidence: 99%

Section: Proliferation Of Rat Pituitary Cells During Ontogenesismentioning

confidence: 99%

See 1 more Smart Citation

Proliferation and differentiation of rat anterior pituitary cells

Taniguchi

Yasutaka

Kominami

et al. 2002

Anatomy and Embryology

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“…We have studied, by quantitative immunocytochemistry, the proliferation of corticotrophs and thyrotrophs during late fetal and early postnatal periods, and present data indicating that mitosis contributes considerably to the proliferation of these cell types (Taniguchi et al 2000(Taniguchi et al , 2001a(Taniguchi et al , 2001b. In this study we examined the proliferation and differentiation of somatotrophs and mammotrophs quantitatively by double immunostaining of pituitary sections using anti-bromodeoxyuridine (BrdU), and anti-rat GH or anti-rat PRL.…”

Section: Introductionmentioning

confidence: 98%

Proliferation and differentiation of pituitary somatotrophs and mammotrophs during late fetal and postnatal periods

Taniguchi

Yasutaka

Kominami

et al. 2001

Anatomy and Embryology

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Proliferation of somatotrophs and mammotrophs in the rat pituitary during late fetal and postnatal periods up to 4 weeks after birth was quantitatively studied with the double immunostaining of bromodeoxyuridine and the hormones produced by them. Somatotrophs were first detected in 18.5-day fetuses and rapidly increased in number throughout the periods studied. The cells labeled with both anti-BrdU and anti-GH were few in number until shortly before birth and then increased conspicuously during the first 10 days after birth. Mammotrophs were detected at gestational day 19.5 but they were few until the second week after birth, when their number began to increase rapidly. The percentage of the number of the cells double-labeled with both anti-BrdU and anti-GH to all somatotrophs was 8.3% at the most. This was about the same as that of corticotrophs during the late fetal period and that of thyrotrophs in the early postnatal period. In contrast, the percentage of double-labeled cells to all mammotrophs was 3.8% as a maximum, which is lower than the values for somatotrophs, corticotrophs, or thyrotrophs, indicating a smaller contribution of mitosis to mammotroph proliferation. It is possible that this smaller contribution is compensated for by transdifferentiation of cells committed to become the somatotroph lineage. However, coexistence of GH and PRL was not observed in the present material.

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“…It was demonstrated that proliferation of corticotrophs was most intensive on day 19 of fetal development (Taniguchi et al 2000(Taniguchi et al , 2001. Dx, as a well-known inhibitor of mitotic activity in various cell types (Kim et al 2004) decreased the rate of division of both immature cells and existing fetal ACTH cells in 19-day-old fetuses.…”

Section: Discussionmentioning

confidence: 98%

The pituitary-adrenal axis of fetal rats after maternal dexamethasone treatment

Manojlović‐Stojanoski¹,

Nestorović²,

Negić³

et al. 2005

Anat Embryol

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Elevated glucocorticoid level in the gravid female circulation affects number of endocrine functions in fetuses and offspring. In this research female rats were injected with dexamethasone (Dx) in three consecutive daily doses of 1.0, 0.5, 0.5 mg/kg body weight, starting from day 16 of pregnancy. The influence of this treatment on the pituitary adrenocorticotrophic (ACTH) cells and adrenal glands of 19-day-old fetuses was examined immunocytochemically and by morphometric analysis. Moreover, the proliferative activity of adrenocortical cells was estimated after application of the mitotic inhibitor Oncovine. Administration of Dx to pregnant rats induced a decline of fetal ACTH cell immunopositivity and significant decreases of ACTH cell volume (23%, p < 0.05), volume density (41%, p < 0.05), and its number per unit area (17%, p < 0.05) in comparison to the control 19-day-old fetuses. Reduced proliferative activity of adrenocortical cells (31%; p < 0.05) in zona glomerulosa, as well as the volume of this zone were detected. The volume and number of fetal adrenocortical cells in the inner zone and chromoblasts were not significantly reduced after Dx treatment of pregnant rats. These results show that maternal Dx administration in the period when the fetal hypothalamo-pituitary-adrenal (PA) axis begins its function inhibited the PA axis. Reduced ACTH cell function and mitotic activity led to suppression of adrenocortical cell multiplication in zona glomerulosa, the region of the adrenal cortex where most proliferating cells were found in control 19-day-old fetuses. Thus, increased glucocorticoid levels during late pregnancy caused developmental modifications involving the fetal PA axis, which could be the basis of the altered endocrine responsiveness in adult life.

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Mitoses of existing corticotrophs contribute to their proliferation in the rat pituitary during the late fetal period

Cited by 18 publications

References 11 publications

Proliferation and differentiation of rat anterior pituitary cells

Proliferation and differentiation of rat anterior pituitary cells

Proliferation and differentiation of pituitary somatotrophs and mammotrophs during late fetal and postnatal periods

The pituitary-adrenal axis of fetal rats after maternal dexamethasone treatment

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