Tumor growth hormone-secreting

Klingebiel R, Foisting M, Bruckmann H, Dorfler A, Jordan M, Buchfelder M, Knauth M. Tumor volume of growth hormone-secreting pituitary adenomas during treatment with pegvisomant a prospective multicenter study. J Clin Endocrinol Metab 2010 95(2) 552-8. 

Dopamine agonists may be appropriate for patients with mildly elevated insulin-like growth factor I levels who have growth hormone and prolactin co-secreting tumors. 

B. Indications and use Sandostatin is indicated to reduce blood levels of growth hormone and IGF-I (somatomedin-C) in acromegaly patients who have had inadequate response to or cannot be treated with surgical resection, pituitary irradiation, or bromocriptine mesylate at maximally tolerated doses. It is also indicated for the symptomatic treatment of patients with metastatic carcinoid tumors, where it suppresses or inhibits the severe diarrhea and flushing episodes associated with the disease, and for the treatment of the profuse watery diarrhea associated with VIP (vasoactive intestinal peptide)-secreting tumors (vipomas). 

A dopamine agonist alone or in combination with pituitary surgery, irradiation, or octreotide may be used to treat acromegaly. Acromegalic patients seldom respond adequately to bromocriptine unless the pituitary tumor secretes prolactin as well as growth hormone. 

In 1982 Guillemin et al. 84) and Rivier et al. 85) isolated 3 peptides 43a with GRF activity (stimulation of the secretion of growth hormone) from human pancreatic tumor cells, and synthesized them by the solid-phase method ... 

GRF has been isolated and characterized from a human tumor of the pancreas (61) as well as from rat (62), porcine (63), bovine (64), caprine (65), ovine (65), and human (65) hypothalamus stalk-median eminence. It is a 40-44-amino-acid peptide hormone produced in the arcuate nucleus of the hypothalamus and released from neurosecretory nerve terminals of these arcuate neurons, and it is carried by the hypothalamo-hypophysial portal circulation to the anterior pituitary gland where it stimulates growth hormone (GH) secretion (66). 

Bulatov AA, Martynov AV, Grigor ian AL, Komolov IS. Molecular forms of human growth hormone and prolactin, secreted by cultured pituitary tumor cells. Biokhimiia 1995 60 1637-46. 

Thymic regrowth and reactivation of thymic endocrine activity may occur in older animals by different endocrinological or nutritional manipulations than in young animals. Intrathymic transplantation of pineal gland or treatment with melatonin, implantation of a growth hormone (GH) secreting tumor cell line or treatment with exogenous... 

The patient may complain of symptoms related to local effects of the growth hormone (GH)-secreting tumor such as headache and visual disturbances. Other symptoms related to elevated GH and insulin-like growth factor-1 (IGF-I) concentrations include excessive sweating, neuropathies, joint pain, and paresthesias. 

Somatostatin acts via specific receptors, which belong to the seven transmembrane G-protein coupled superfam-ily. Somatostatin receptors (sst) are categorized into five major subtypes designated sst 1-5. The inhibitory action of somatostatin on hormone secretion is mediated by sst2, whereas suppression of cell growth is mediated by sst 1, 2, and 5. The effects of somatostatin on apoptosis are mediated by ssts 2 and 3. Immunohistochemical analysis of ssts has been used to gauge the responsiveness of NE tumors to somatostatin analogs. ... 

Studies have shown that, in addition to the conventional peptide hormones of pancreatic islets (insulin, glucagon, somatostatin, and pancreatic polypeptide), these tumors can also secrete (and express) ectopic peptides, in particular gastrin and VIP (vasoactive intestinal peptide),but on occasion also ACTH (adrenal corticotropic hormone),antidiuretic hormone (ADH), MSH (melanocyte-stimulating hormone), calcitonin, neurotensin, secretoneurin, 754-356 PTH (parathyroid hormone-like peptide),growth hormone and growth hormone releasing factor, secretogranin inhibin/activin, i prohormone... 

Berger G, Trouillas J, Bloch B, et al. Multihormonal carcinoid tumor of the pancreas. Secreting growth hormone-releasing factor as a cause of acromegaly. Cancer. 1984 54 2097-2108. 

Human placental lactogen (HPL) is a 22-kD protein with partial homology to growth hormone. HPL is secreted by syncytiotrophoblastic cells in choriocarcinoma and intermediate trophoblasts in a testicular trophoblastic tumor that is a counterpart to a uterine placental site trophoblastic tumor. 

In addition to its effect on GH secretion, octreotide can decrease tumor size—although tumor growth generally resumes after octreotide treatment is stopped. Octreotide also has significant inhibitory effects on thyrotropin secretion, and it is the treatment of choice for patients who have thyrotrope adenomas that oversecrete thyroid-stimulating hormone (TSH) and who are not good candidates for surgery. 

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