Mitotic activity of gonadotropes in the anterior pituitary of the castrated male rat

1985 ◽  
Vol 240 (2) ◽  
Author(s):  
Kinji Inoue ◽  
Shigeyasu Tanaka ◽  
Kazumasa Kurosumi
Keyword(s):  
Mitotic Activity ◽  
Anterior Pituitary ◽  
Male Rat

scholarly journals The effects of testosterone and oestrogen on gonadectomised and intact male rat anterior pituitary mitotic and apoptotic activity

2006 ◽  
Vol 188 (3) ◽  
pp. 387-396 ◽  
Author(s):  
L A Nolan ◽  
A Levy
Keyword(s):  
Mitotic Activity ◽  
Anterior Pituitary ◽  
Male Rats ◽  
Male Rat ◽  
Gonadal Hormone ◽  
High Dose ◽  
Dependent Manner ◽  
Intact Male ◽  
Hormone Production ◽  
Apoptotic Activity

We have used a direct, non-immunochemical and highly accurate method to quantify the effects of testosterone and oestrogen on mitotic and apoptotic activity in the young, male rat anterior pituitary in vivo. Surgical gonadectomy resulted in a 3-fold increase in mitotic activity by the fourth post-operative day, which returned gradually to levels seen in intact animals over the subsequent 3–4 weeks. Both a single dose of Sustanon, a mixture of long-acting testosterone esters in arachis oil, and the same dose divided over 7 days (starting 6 days after gonadectomy), initially suppressed mitotic activity to levels seen in intact animals, but was associated after 48–96 h with a wave of increased mitotic activity. The latter was blocked by co-administration of Sustanon with the non-steroidal aromatase inhibitor letrozole and was not seen when the non-aromatisable androgen dihydrotestosterone was substituted for Sustanon. Oestrogen alone in gonadectomised and intact rats produced a marked increase in mitosis as expected. With the exception of a transient increase in response to a single high-dose injection of Sustanon in gonadectomised animals, apoptotic activity was unaffected by all of the above. This study suggests that pituitary mitotic activity is tonically inhibited by gonadal hormone production (at least in the short term) in adult male rats. The study also suggests that supraphysiological testosterone treatment – while unable to reduce anterior pituitary mitotic activity in untreated, intact animals –suppresses the early increase in mitotic activity induced by gonadectomy. Oestrogen, either exogenous or generated locally by aromatisation, stimulates anterior pituitary mitotic activity in a time-dependent manner.

Age-related changes in the regional distribution of hormones in the male rat anterior pituitary

1988 ◽  
Vol 152 (3) ◽  
pp. 1213-1220 ◽  
Author(s):  
Jerome M. Goldman ◽  
Ralph L. Cooper ◽  
Georgia L. Rehnberg ◽  
W. Keith McElroy ◽  
Joy F. Heln ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Regional Distribution ◽  
Male Rat ◽  
Age Related ◽  
Age Related Changes

EFFECTS OF STILBOESTROL ON GROWTH HORMONE SECRETION AND PITUITARY CELL PROLIFERATION IN THE MALE RAT

1971 ◽  
Vol 51 (3) ◽  
pp. 473-481 ◽  
Author(s):  
H. M. LLOYD ◽  
J. D. MEARES ◽  
JOAN JACOBI ◽  
FRANCES J. THOMAS
Keyword(s):  
Growth Hormone ◽  
Cell Proliferation ◽  
Mitotic Activity ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Mean Value ◽  
Pituitary Cell ◽  
Male Rats ◽  
Male Rat ◽  
Serum Growth Hormone

SUMMARY A single 12 mg dose of stilboestrol dipropionate given to 100-day-old male rats resulted in increased pituitary mitotic activity, pituitary weight and serum growth hormone; the latter rose from a mean value of 20 ng/ml to a maximum of 342 ng/ml 9 days later. Serum growth hormone and pituitary mitotic activity then gradually diminished but were still slightly increased on day 28. Serum growth hormone and pituitary weight were significantly correlated during the periods of rapidly rising and of sustained high levels of serum growth hormone. Indices of mitotic activity were correlated with serum growth hormone during the periods of rapidly rising and of falling levels of serum growth hormone.

Involvement of the adrenal glands and testis in gap junction formation via testosterone within the male rat anterior pituitary gland

2012 ◽  
Vol 75 (12) ◽  
pp. 1632-1638 ◽  
Author(s):  
Eisuke Sakuma ◽  
Ikuo Wada ◽  
Takanobu Otsuka ◽  
Kenjiro Wakabayashi ◽  
Kinya Ito ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Gap Junction ◽  
Anterior Pituitary ◽  
Adrenal Glands ◽  
Anterior Pituitary Gland ◽  
Male Rat ◽  
Junction Formation

scholarly journals Immunocytochemical Localization of Vasopressin V1a Receptors in the Rat Pituitary Gonadotropes

Endocrinology ◽  
2002 ◽  
Vol 143 (11) ◽  
pp. 4385-4388 ◽  
Author(s):  
Hélène Orcel ◽  
Vicky A. Tobin ◽  
Gérard Alonso ◽  
Alain Rabié
Keyword(s):  
Anterior Pituitary ◽  
Direct Action ◽  
Secretory Granules ◽  
Male Rat ◽  
Rt Pcr ◽  
V1a Receptor ◽  
Cytoplasmic Vesicles ◽  
Rat Pituitary ◽  
Vasopressin V1a Receptor ◽  
Subcellular Level

Abstract Immunocytochemical labeling using a specific antibody against vasopressin V1a receptor allowed the localization of this receptor within a subset of cells from male rat anterior pituitary. The presence of transcripts of the corresponding gene in the anterior pituitary was confirmed by RT-PCR. Multiple immunocytochemical labeling combined with confocal microscopy allowed the identification of the V1a-labeled cells as gonadotropes. At the subcellular level, the vasopressin V1a receptor was mainly associated with cytoplasmic vesicles dispersed throughout the cell, which were not the secretory granules storing LH or FSH. In addition to effects exerted by vasopressin via central targets involved in the reproductive pathways, the presence of vasopressin V1a receptors on gonadotropes supports the controversial hypothesis of a local direct action of the neuropeptide on this cell type.

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