Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00691 (EE2)
 7,802 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the binding of 125I-human growth hormone (hGH) to crude 100,000 X g membrane preparations from rat liver, and have studied factors which might regulate the capacity and affinity of hGH binding sites. Membrane preparations have livers of pregnant rats bound between 8% and 18% of the 125I-hGH initially added, and 70%-80% of that bound was displaced by 1 mug of unlabeled hGH. Humans prolactin (hPrl) displaced 125 I-hGH in a manner parallel to hGH itself but with about one-third the potency. Ovine, porcine, and rat Prl, and rat and bovine GH were much less effective. Scatchard analysis of specific hGH binding by a variety of different rat liver membrane preparations revealed a single order of binding site in each case with a binding affinity of 0.93-1.62 X 10(-9) M-1. Membranes from pregnant rats had twice the binding capacity of membranes from nonpregnant female rats, and about six times the capacity of sites present in preparations from normal adult male rats and hypophysectomized (Hx) male or female rats. Female or male rats with extremely high circulating GH an Prl levels, due to the presence of transplantable GH/Prl secreting pituitary tumors showed a significantly greater binding capacity than did the pregnant rats. Estradiol (E2) treatment (25 mug/day for 10-12 days) of normal male rats led to an increase in specific hGH binding. Treatment of hypophysectomized male rats with bovine GH (100 or 500 mug/day) +/- E2 (25 mug/day) for 5-10 days stimulated both body weight gain and the incorporation of sulfate by cartilage from the treated rats, but no significant increase was observed in the characteristics of 125I-hGH binding. These results indicate that high levels of E2, GH, and/or Prl play an important role in the regulation of hGH binding sites in rat liver membranes. The restoration of binding sites in liver from hypophysectomized rats, however, apparently requires additional factors which are as yet unidentified. The role of the hGH binding sites in the physiologic actions of GH also remains to be determined.
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PMID:Pituitary regulation of human growth hormone binding sites in rat liver membranes. 17 42

To identify the hormones which affect lactogenic receptors in the liver of chronically hypophysectomized female rats, hormones were injected s.c. for 7 days. Specific binding (%, SB) of labelled ovine prolactin (PRL) in liver membrane preparations (1000,000 X g pellet) of controls was 1%. Estradiol (E2), cortisone (Con), ACTH or bovine growth hormone (bGH) treatment did not induce hepatic binding sites for PRL. Human GH and a single dose of 2mg PRL (but not lower doses) increased SB of PRL. Treatment with oPRL plus ACTH was less effective than hGH plus ACTH (13 vs 28%); combinations of oPRL plus Con as well as administration of oPRL plus ACTH to hypophysectomized and adrenalectomized female rats did not induce SB for PRL. Therapy with oPRL plus hGH (26%) was more potent than oPRL plus bGH (2%). These studies suggest that PRL, GH, and ACTH induce and in concert with sex steroids, modulate the lactogenic receptors in the female rat liver. The effect of ACTH is not due to increased adrenal corticoid secretion.
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PMID:Induction of lactogenic receptors. I. In the liver of hypophysectomized female rats. 18 47

Tamoxifen (ICI 46474), an antiestrogen, was given to 89 selected patients with stage IV breast cancer at a dose of 20 mg orally every 12 hours. Forty-seven percent of the patients had objective tumor regression averaging 11+ months with 25 of 42 women still in remission. In the first 39 patients where the minimum follow-up period is 16 months the average duration of remission is more than 15 months with 8 of 19 patients still in remission. These results are approaching those of surgical hypophysectomy, where, in our experience the average remission lasts about 18 months. Thus, Tamoxifen is a highly effective antitumor agent and is probably the initial treatment of choice for women with hormone responsive breast cancer. Antiestrogen induced objective remissions in 5 of 19 patients who had previously responded to surgical hypophysectomy, and 5 additional patients showed no progression of disease lasting 15+ months. Estradiol and estrone were detectable in the serum of these patients whereas, prolactin and growth hormone were not detectable. Thus, antiestrogen can induce remissions in some patients in the absence of the pituitary gland, and this constitutes additional palliation and provides evidence that estrogens can directly stimulate tumor growth. Four of 7 patients who obtained remissions from Tamoxifen obtained further improvement from hypophysectomy, and 1 of 8 patients who failed to benefit from antiestrogen improved after hypophysectomy. These results suggest that prolactin and growth hormone may also play a role in stimulating tumor growth in some patients.
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PMID:Treatment of breast cancer with antiestrogen: approach to medical hypophysectomy? 61 66

Estradiol (0.2 mug), injected subcutaneously for 10 days to adult male rats, increased plasma growth hormone (GH) levels as compared with oil-treated controls. In estradiol-pretreated (10 days), urethane-anesthetized rats, the first as well as the second of two successive intracarotid injections, at 1-hour intervals, of one rat stalk median eminence equivalent evoked a significant rise in plasma radioimmunoassayable GH. Under the same conditions, cerebral cortex extracts (1 equivalent) induced a slight elevation whereas vasopressin (30 mU) or serotonin (200 ng) were ineffective. These results indicate that estrogen-primed, urethane-anesthetized rats can be used to demonstrate GH-releasing activity in rat SME extracts.
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PMID:Effect of rat stalk median eminence extracts on rat GH secretion in vivo. 79 47

The effects of Ovral (norgestrel plus ethinyl estradiol) on plasma growth hormone (GH) levels and glucose tolerance were investigated in Sprague-Dawley and a carbohydrate-sensitive strain (BHE) of rats. Sodium pentobarbitol was used to stimulate GH production. Fasting blood glucose levels were not altered by treatment with Ovral in either strain. However, under a glucose load, Sprague-Dawley rats developed an impaired tolerance during the latter part of the glucose tolerance test, while treatment with the oral contraceptive improved an impaired response to glucose load in BHE animals. A good correlation between changes in GH and glucose tolerance during treatment could not be established. Sprague-Dawley rats had a significant (p less than .01) decrease in the rate of body weight increase compared with controls.
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PMID:The effects of an oral contraceptive on plasma growth hormone and glucose tolerance in two strains of rats. 84 89

Altered carbohydrate metabolism associated with fibrosarcomas and chondrosarcomas has been well-documented in past literature. This report describes abnormal carbohydrate metabolism in 2 osteosarcoma patients, and abnormalities in growth hormone and somatomedin serum levels. Experimental evidence is presented showing in vitro suppression of osteosarcoma tumor cell proliferation by 17 beta Estradiol. Estrogen inhibition of linear bone growth, cartilage proliferation, and somatomedin is discussed with reference to possible estrogen therapy in osteosarcoma.
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PMID:Investigation of carbohydrate metabolism and somatomedin in osteosarcoma patients. 105 23

Recent evidence suggests that endocrine factors play an important role in the natural history of osteosarcoma. The occurrence of this tumor in the metaphysis of rapidly growing adolescents, coupled with increased female survival led to the investigation of the effects of various hormones on cultured osteosarcoma cells. The in vitro effects of physiologic concentrations of human growth hormone, 17beta estradiol, and progesterone on cultured osteosarcoma cells and chondrocytes are presented. Growth hormone significantly enhances 3H-thymidine incorporation in osteosarcoma cells and chondrocytes, in the presence of human serum. The use of other sera, culture media, or heat inactivation of the human serum abolishes this effect. Estradiol and progesterone, alone, or in combination produce significant suppression of DNA synthesis in cultured tumor cells. Several sera contain a heat-labile factor which has the capacity to block the suppressive effect of estradiol. This factor could be overcome by increasing the concentration of hormone, or by heat-inactivation of the serum. The use of hormone therapy in the treatment of osteosarcoma has never been reported, despite its demonstrated value in certain other malignancies. In light of these observations and considering the poor prognosis in this disease it seems reasonable to initiate a study of adjunctive hormone therapy in osteosarcama.
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PMID:Hormone suppression of DNA synthesis in cultured chondrocyte and osteosarcoma cell line. 105 8

The effect of cortisol and estradiol on the stimulation by growth hormone of liver mitochondrial protein synthesis in hypophysectomized rats has been studied by measuring radioactive leucine incorporation in vivo and in vitro. Estradiol inhibited the stimulatory effect of growth hormone on incorporation into mitochondrial and microsomal proteins. Cortisol blocked the stimulatory effect of growth hormone on mitochondrial protein synthesis. The stimulatory effects of cortisol and growth hormone on microsomal incorporation were not additive. Gain in body weights corresponded with their effects on mitochondrial and microsomal protein synthesis. These results show that steroid hormones may act as regulators of the growth hormone effect.
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PMID:Growth hormone and liver mitochondrial protein synthesis effect of cortisol and estradiol. 115 77

The effects of estradiol and growth hormone-releasing hormone (GHRH) on galanin release from anterior pituitary cells were examined in vitro. 17-beta-Estradiol (0.001-10 nM) increased galanin secretion from anterior pituitary cells in a concentration-dependent manner. Estradiol (10 nM) increased galanin release 300 and 600% from pituitary cells of ovariectomized and male rats, respectively. Immunocytochemical studies demonstrated that estradiol (10 nM) increased the number of galanin-containing cells twofold after 4 days in culture. Growth hormone-releasing hormone (1 and 10 nM) increased and SRIF (1 and 10 nM) decreased galanin release from pituitary cells of ovariectomized and male rats. We conclude that estradiol increases galanin release by a direct effect on pituitary cells, in part by increasing the number of pituitary cells synthesizing galanin. In addition, GHRH stimulates galanin release when estradiol levels are low.
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PMID:Regulation of galanin secretion from pituitary cells in vitro by estradiol and GHRH. 128 31

The effect of the alpha 2-adrenoceptor agonist, clonidine, on plasma growth hormone (GH), plasma 3-methoxy-4-hydroxyphenylethylenegylcol (MHPG), blood pressure and sedation were studied in 16 menopausal subjects before and 6 wk after a 100-mg implant of estradiol. The specific binding of tritiated yohimbine to intact platelets also was studied. Estradiol implants increased basal GH output and reduced baseline MHPG and sedation scores. However, none of the subsequent responses to clonidine were altered. Platelet yohimbine binding also was unchanged following the implant. Both observer- and self-rating scales showed a marked reduction in anxiety and depression scores. The results suggest that estradiol may alter some indices of noradrenergic function, but that the mechanism does not involve alterations in alpha 2-adrenoceptor sensitivity.
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PMID:Effect of estradiol implant on noradrenergic function and mood in menopausal subjects. 131 72


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