Role of the ovary in the sexual differentiation of prolactin and growth hormone cells in the mouse adenohypophysis: a stereological morphometric study by electron microscopy

1982 ◽  
Vol 93 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Fumihiko Sasaki ◽  
Masao Sano
Keyword(s):  
Growth Hormone ◽  
Adult Female ◽  
Morphometric Study ◽  
Vaginal Opening ◽  
Prolactin Cells ◽  
Pituitary Development ◽  
Plateau Level ◽  
Stimulation Of ◽  
Male Pattern

The number of prolactin and growth hormone cells was estimated in the mouse anterior pituitary gland. During postnatal development in females, the number of prolactin cells showed a rectilinear increase from about 0·3 × 104 at 20 days of age to about 21 × 104 in adult female mice, while growth hormone cells gradually increased from about 7 × 104 on day 20 to about 20 × 104 on days 60–70, with a plateau level of about 14 × 104 cells around puberty. Prolactin cells were more abundant in adult female (about 21 × 104) than in male (about 5 × 104) mice, while there were fewer growth hormone cells in adult females (about 20 × 104) than in males (about 25 × 104). Ovariectomy before puberty induced the male pattern of pituitary development by inhibition of the increase in the number of prolactin cells and stimulation of that of growth hormone cells. In animals ovariectomized just before puberty (30–35 days of age) or 5 days after vaginal opening (40–45 days of age) the number of prolactin cells showed no further increase after the day of operation. On the other hand, when animals were ovariectomized at 10 days of age, the number of prolactin cells increased to the level found in 30-day-old normal control females. This implies that the increase in prolactin cells between 10 and 30 days of age is not dependent on the ovary, although after puberty the increase does depend on the presence of the ovary.

ROLE OF THE OVARY IN THE SEXUAL DIFFERENTIATION OF PROLACTIN AND GROWTH HORMONE CELLS IN THE MOUSE ADENOHYPOPHYSIS DURING POSTNATAL DEVELOPMENT: A STEREOLOGICAL MORPHOMETRIC STUDY BY ELECTRON MICROSCOPY

1980 ◽  
Vol 85 (2) ◽  
pp. 283-289 ◽  
Author(s):  
F. SASAKI ◽  
M. SANO
Keyword(s):  
Growth Hormone ◽  
Cell Population ◽  
Sexual Differentiation ◽  
Anterior Pituitary ◽  
Morphometric Study ◽  
Pituitary Cells ◽  
Prolactin Cells ◽  
Cell Organelles ◽  
Pituitary Glands

To clarify the role of the ovary in the sexual differentiation of prolactin and growth hormone cells, the anterior pituitary glands of mice ovariectomized before or after puberty were studied by a stereological morphometric technique with the electron microscope. A marked sex difference was observed in the relative proportions of these two types of cells in normal adult control animals. In male mice about 52% of anterior pituitary cells were growth hormone cells and about 10% were prolactin cells, while in female mice prolactin cells represented about 39% and growth hormone cells about 37% of the anterior pituitary cell population. Ovariectomy before puberty reduced the proportion of prolactin cells to about 10% and increased growth hormone cells to about 50% of the cell population. The size of prolactin cells and the development of their cell organelles was also reduced. Ovariectomy after puberty had less marked effects. These results suggest that ovariectomy before puberty induced the male phenotype by inhibition of the differentiation of prolactin cells and stimulation of the differentiation of growth hormone cells. The significance of these results in relation to the sexual differentiation of the pituitary gland is discussed.

The Role of the Pituitary Gland in Spontaneous Canine Mammary Tumorigenesis

1980 ◽  
Vol 17 (1) ◽  
pp. 2-16 ◽  
Author(s):  
M. F. El Etreby ◽  
R. Müller-Peddinghaus ◽  
A. S. Bhargava ◽  
M. R. Fath El Bab ◽  
K.-J. Gräf ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Morphological Changes ◽  
Mammary Tumorigenesis ◽  
Secretory Activity ◽  
Serum Prolactin ◽  
Prolactin Cells ◽  
Basal Serum ◽  
Mammary Tumours

The morphological changes of the pituitary gland of 29 female dogs with spontaneous mammary tumours or dysplasia or both were correlated with basal serum prolactin, growth hormone, adrenocorticotrophin, thyrotrophin, cortisol, total cholesterol, thyroxine and thyroid binding index as well as with lesions in other endocrine and genital organs. Spontaneous canine mammary tumorigenesis seemed to be associated with increased secretory activity of growth hormone rather than prolactin cells. Depressed secretory activity of follicle stimulating hormone-, luteinizing hormone- and thyrotrophin-producing cells, as well as signs of inhibition of ovarian (anovulation) and thyroid function, were also consistent findings in dogs with mammary tumours. There also was disturbance in pituitary-adrenal function associated with hyperplastic and neoplastic changes of the pituitary gland and adrenal cortex.

scholarly journals Receptors for interleukin-3 (IL-3) and growth hormone mediate an IL-6- type transcriptional induction in the presence of JAK2 or STAT3

Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1671-1679 ◽  
Author(s):  
Y Wang ◽  
KK Morella ◽  
J Ripperger ◽  
CF Lai ◽  
DP Gearing ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Expression Vectors ◽  
Protein Activation ◽  
Stat Proteins ◽  
Interleukin 3 ◽  
Dose Dependent ◽  
Transcriptional Induction ◽  
Stimulation Of ◽  
Stat Pathway

To determine the specificity of signal transducer and activator of transcription (STAT) protein activation by box 3 motif-deficient hematopoietin receptors, expression vectors encoding the receptors for growth hormone, interleukin-3 (IL-3), and IL-4 were transiently transfected into COS-1 cells, together with expression vectors for Janus kinases (JAKs) and STAT proteins. Each receptor mediated a dose- dependent activation of STAT1 and STAT3, and for IL-3R and GHR this process was enhanced by JAK2. The data suggest that a box 3 motif in the cytoplasmic domain of the signal-transducing receptor to the JAK/STAT pathway. Transfection of the receptors, in combination with STAT3, into HepG2 cells reconstituted a cytokine-dependent stimulation of gene transcription through IL-6 response elements, providing evidence for a functional role of STAT3 in controlling gene expression.

Evidence for a Role of Protein Kinase C in the Stimulation of Lipolysis by Growth Hormone and Isoproterenol*

Endocrinology ◽  
1990 ◽  
Vol 126 (6) ◽  
pp. 2973-2982 ◽  
Author(s):  
ERELA GORIN ◽  
LIH-RUEY TAI ◽  
THOMAS W. HONEYMAN ◽  
H. MAURICE GOODMAN
Keyword(s):  
Growth Hormone ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Stimulation Of

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

2002 ◽  
Vol 283 (1) ◽  
pp. E172-E177 ◽  
Author(s):  
C. B. Djurhuus ◽  
C. H. Gravholt ◽  
S. Nielsen ◽  
A. Mengel ◽  
J. S. Christiansen ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Young Male ◽  
Abdominal Adipose Tissue ◽  
Male Volunteers ◽  
Glucagon And Insulin ◽  
Stimulation Of

Cortisol's effects on lipid metabolism are controversial and may involve stimulation of both lipolysis and lipogenesis. This study was undertaken to define the role of physiological hypercortisolemia on systemic and regional lipolysis in humans. We investigated seven healthy young male volunteers after an overnight fast on two occasions by means of microdialysis and palmitate turnover in a placebo-controlled manner with a pancreatic pituitary clamp involving inhibition with somatostatin and substitution of growth hormone, glucagon, and insulin at basal levels. Hydrocortisone infusion increased circulating concentrations of cortisol (888 ± 12 vs. 245 ± 7 nmol/l). Interstitial glycerol concentrations rose in parallel in abdominal (327 ± 35 vs. 156 ± 30 μmol/l; P = 0.05) and femoral (178 ± 28 vs. 91 ± 22 μmol/l; P = 0.02) adipose tissue. Systemic [3H]palmitate turnover increased (165 ± 17 vs. 92 ± 24 μmol/min; P = 0.01). Levels of insulin, glucagon, and growth hormone were comparable. In conclusion, the present study unmistakenly shows that cortisol in physiological concentrations is a potent stimulus of lipolysis and that this effect prevails equally in both femoral and abdominal adipose tissue.

scholarly journals Stimulation of growth hormone by kisspeptin antagonists in ewes

2018 ◽  
Vol 237 (2) ◽  
pp. 165-173 ◽  
Author(s):  
J T Smith ◽  
A Roseweir ◽  
M Millar ◽  
I J Clarke ◽  
R P Millar
Keyword(s):  
Growth Hormone ◽  
Potential Role ◽  
Third Ventricle ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells ◽  
Physiological Conditions ◽  
Gh Secretion ◽  
Stimulation Of

Kisspeptin signalling is indispensable for fertility, stimulating gonadotropin-releasing hormone (GnRH) secretion and mediating gonadal steroid feedback on GnRH neurons. Moreover, kisspeptin neurons have been implicated in other non-reproductive neuroendocrine roles. Kisspeptin appears to also regulate growth hormone secretion but much of the data appear contradictory. We sought to clarify a potential role of kisspeptin in growth hormone (GH) regulation by examining the effect of kisspeptin antagonists on GH secretion in ewes under various physiological conditions. Our data show clear and robust increases in GH secretion following lateral ventricle or third ventricle infusion of kisspeptin antagonists p-234 and p-271 in either ovariectomized or anestrous ewes. Central infusion of kisspeptin-10 had no effect on GH secretion. To determine the level at which kisspeptin may influence GH secretion, we examined expression of the cognate kisspeptin receptor, GPR54, in pituitary cells and showed by immunocytochemistry that the majority of somatotropes express GPR54 while expression was largely negative in other pituitary cells. Overall, we have demonstrated that blocking kisspeptin signalling by antagonists stimulates GH secretion in ewes and that this is likely mediated by inhibiting endogenous kisspeptin activation of GPR54 expressed on somatotropes. The findings suggest that endogenous kisspeptin inhibits GH secretion through GPR54 expressed on somatotropes.

Evidence for the role of growth hormone as a part of a 'light–pituitary axis' in growth and smoltification of Atlantic salmon (Salmo salar)

1976 ◽  
Vol 54 (4) ◽  
pp. 544-551 ◽  
Author(s):  
M. P. Komourdjian ◽  
R. L. Saunders ◽  
J. C. Fenwick
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
High Salinity ◽  
Separate Experiment ◽  
Pars Intermedia ◽  
Prolactin Cells ◽  
Atlantic Salmon Salmo Salar ◽  
Natural Photoperiod

Atlantic salmon (Salmo salar) parr were subjected to one of two photoperiod regimens: a simulated natural photoperiod, or a reciprocal photoperiod (with a light-to-dark ratio opposite to that of the natural photoperiod). The animals were held at 10 °C from mid-December onward and were sampled at 3-week intervals.By February, salmon held under the reciprocal photoperiod were significantly longer, had lower condition factors, and looked and behaved more like smolts than did those under the natural photoperiod. A separate experiment showed that salinity tolerance increased at this time. In June the situation was reversed; the salmon kept under the natural photoperiod showed greatest growth and high salinity tolerance.Longer days in either regimen coincided with an increase in number and apparent activity of pituitary somatotrops of the animals. Adrenocorticotropin (ACTH), pars intermedia, and prolactin cells were also judged to be active under these conditions. A role for growth hormone and other peptides as components of a 'light–pituitary axis' is discussed in relation to the parr–smolt transformation of Atlantic salmon.

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