Growth hormone: a reproductive endocrine-paracrine regulator?

2000 ◽  
Vol 5 (3) ◽  
pp. 175-182 ◽  
Author(s):  
K. Hull
Keyword(s):  
Growth Hormone ◽  
Reproductive Endocrine

Influence of in vivo Reproductive Endocrine State on Growth Hormone-Releasing Factor Stimulated Adenylate Cyclase Activity in Anterior Pituitary Fragments

1993 ◽  
Vol 57 (1) ◽  
pp. 63-69
Author(s):  
Steven M. Gabriel ◽  
Edward H. Hunnicut ◽  
William J. Millard ◽  
Thomas M. Badger ◽  
James A. Nathanson
Keyword(s):  
Growth Hormone ◽  
Adenylate Cyclase ◽  
Anterior Pituitary ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Growth Hormone Releasing Factor ◽  
Reproductive Endocrine

scholarly journals Leptin modulates fertility under the influence of elevated growth hormone as modeled in oMt1a-oGH transgenic mice

2004 ◽  
Vol 182 (3) ◽  
pp. 421-432 ◽  
Author(s):  
AD Thomas ◽  
JD Murray ◽  
AM Oberbauer
Keyword(s):  
Growth Hormone ◽  
Pregnancy Rate ◽  
Reproductive Function ◽  
Treatment Groups ◽  
Reproductive Axis ◽  
Reproductive Endocrine ◽  
Estrous Cyclicity ◽  
Plasma Leptin ◽  
Old Females ◽  
Endocrine Axis

Elevated growth hormone (GH) concentrations suppress reproductive function in a variety of species, although it is unclear whether GH directly suppresses reproductive performance, or whether GH activates other pathways to achieve these effects. The ovine metallothionein 1a-ovine GH (oMt1a-oGH) transgenic mouse has been used to model the effects of GH on both body composition and reproductive function. A recent report has documented increased leptin levels in obese oMt1a-oGH mice. Given the importance of leptin in modulation of the reproductive endocrine axis, as well as the reports documenting reduced leptin signal transduction in animals with elevated leptin levels, we hypothesized that high leptin concentrations in response to elevated GH would reduce fertility. To determine the effects of high circulating leptin levels on the reproductive endocrine axis, we assessed hypothalamic neuropeptide Y (NPY) and GnRH expression. At weaning, oMt1a-oGH transgenic (TG) and wild-type (WT) female mice were allocated to one of four treatment groups: oMt1a-oGH females chronically expressing the transgene (TG ON); oMt1a-oGH females expressing the transgene from 3 to 8 weeks of age (TG ON/OFF); WT females receiving the transgene stimulus from 3 to 8 weeks of age (WT ON/OFF); and WT females never receiving the transgene stimulus (WT OFF). Eight-week-old females were housed with males for a 2-week period, after which females were isolated from males and allowed to carry pregnancies to term. Body and gonadal fat pad (GFP) weights, along with plasma leptin concentrations, estrous cyclicity, pregnancy rate and litter characteristics, were recorded for each female. Chronic expression of the oMt1a-oGH transgene resulted in larger leaner mice, and inactivation of the transgene produced obese females. Pregnancy rate was reduced in TG ON females when compared with all other groups, and infertility was associated with elevated leptin levels. In addition, high leptin levels were associated with increased NPY expression, suggesting reduced leptin-signaling capacity, which may contribute to suppression of the reproductive axis in oGH animals.

Association of pituitary adenoma with neuronal christoma: A TEM study

1994 ◽  
Vol 52 ◽  
pp. 232-233
Author(s):  
Eva Horvath ◽  
Kalman Kovacs ◽  
B. W. Scheithauer ◽  
R. V. Lloyd ◽  
H. S. Smyth
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
Pituitary Tumor ◽  
Nervous Tissue ◽  
Alternative Explanation ◽  
Growth Hormone Releasing Hormone ◽  
Cell Hyperplasia ◽  
Releasing Hormone ◽  
Secretory Neurons

The association of a pituitary adenoma with nervous tissue consisting of neuron-like cells and neuropil is a rare abnormality. In the majority of cases, the pituitary tumor is a chromophobic adenoma, accompanied by acromegaly. Histology reveals widely variable proportions of endocrine and nervous tissue in alternating or intermingled patterns. The lesion is perceived as a composite one consisting of two histogenetically distinct parts. It has been suggested that the neuronal component, morphologically similar to secretory neurons of the hypothalamus, may initiate adenoma formation by releasing stimulatory substances. Immunoreactivity for growth hormone releasing hormone (GRH) in the neuronal component of some cases supported this view, whereas other findings such as consistent lack of growth hormone (GH) cell hyperplasia in the lesions called for alternative explanation.Fifteen tumors consisting of a pituitary adenoma and a neuronal component have been collected over a 20 yr. period. Acromegaly was present in 11 patients, was equivocal in one, and absent in 3.

Target Growth Hormone Doses to IGF-1 Levels

2005 ◽  
Vol 39 (10) ◽  
pp. 10
Author(s):  
BETSY BATES
Keyword(s):  
Growth Hormone

Burned Children Benefit From Growth Hormone

2009 ◽  
Vol 40 (8) ◽  
pp. 38
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Growth Hormone
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