Abstract:
:Studies were undertaken to determine the effects of chronic stimulation of opiate receptors on the negative feedback effects of testosterone (T) on luteinizing hormone (LH) secretion in the male rat. In an initial study, castrated male rats received replacement levels of T (2 ng/ml) or chronic morphine (M) treatment for 7 days. When initiated at the time of castration, both T and M treatments prevented the castration-induced hypersecretion of LH. However, when the treatments commenced 2 weeks after castration, only T restored LH secretion to the low levels seen in intact rats. In a second study, rats castrated 2 weeks previously were exposed to chronic M or placebo (control) treatment in the presence of various dosages of T. In rats receiving T alone, LH secretion was unaffected at T levels up to 600 pg/ml serum, but thereafter there was a dose-dependent suppression of LH release by T. Serum T levels which reduced LH secretion by 50% were estimated to be 966 pg/ml. In contrast, in castrated rats receiving both M and T treatment, a 50% reduction in LH secretion was estimated to be at 300 pg T/ml serum and maximal inhibition of LH secretion was achieved at serum T levels of greater than 600 pg/ml. Neither T alone nor M plus T treatment altered the responsiveness of the anterior pituitary to LHRH in vitro. These findings indicate that M may enhance the sensitivity of the hypothalamus to T feedback by approximately 3-fold and raise the possibility of the existence of an opioid-sensitive neural component which may modulate the negative feedback effects of T on LH secretion.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Gabriel SM,Simpkins JW,Kalra SP,Kalra PSdoi
10.1159/000124049subject
Has Abstractpub_date
1985-01-01 00:00:00pages
39-44issue
1eissn
0028-3835issn
1423-0194journal_volume
40pub_type
杂志文章abstract::This study was designed to investigate the effects of penfluridol, a potent neuroleptic calmodulin inhibitor, on basal and secretagogue-stimulated secretion of thyroid-stimulating hormone (TSH), growth hormone (GH), and luteinizing hormone (LH). The drug had no effect on basal TSH or LH release, but decreased GH relea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123548
更新日期:1983-09-01 00:00:00
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journal_title:Neuroendocrinology
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更新日期:1983-12-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125743
更新日期:1991-04-01 00:00:00
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journal_title:Neuroendocrinology
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更新日期:1981-08-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124479
更新日期:1986-01-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126893
更新日期:1995-06-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125708
更新日期:1991-02-01 00:00:00
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更新日期:1988-09-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
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更新日期:1998-12-01 00:00:00
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pub_type: 杂志文章
doi:10.1159/000122650
更新日期:1977-01-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
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更新日期:1990-06-01 00:00:00
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pub_type: 杂志文章
doi:10.1159/000126518
更新日期:1993-07-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126645
更新日期:1994-02-01 00:00:00
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pub_type: 杂志文章
doi:10.1159/000126717
更新日期:1994-07-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123529
更新日期:1983-08-01 00:00:00
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pub_type: 杂志文章
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更新日期:1998-02-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
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更新日期:1989-04-01 00:00:00
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更新日期:1998-10-01 00:00:00
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更新日期:1997-09-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
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更新日期:2017-01-01 00:00:00
abstract::Circadian rhythm of blood corticosterone in adrenalectomized rats with (AT rat) or without adrenal autotransplants was investigated. Blood samples were obtained individually at 4-hour intervals for a 24-hour period per week for 5-7 consecutive weeks by the tail tip incision method. Corticosterone responses of the auto...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123294
更新日期:1982-03-01 00:00:00
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journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124922
更新日期:1988-03-01 00:00:00
abstract::To gain further insight into the regulation of hypothalamic TRH by thyroid hormones, we measured TRH concentration in specific hypothalamic nuclei and preproTRH mRNA levels in the anterior hypothalamus. Adult male rats were decapitated 1, 7, 14 days after thyroidectomy. Micropunches by the method of Palkovitz from sev...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126131
更新日期:1992-03-01 00:00:00
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journal_title:Neuroendocrinology
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更新日期:1994-05-01 00:00:00
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pub_type: 杂志文章,评审
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更新日期:2010-01-01 00:00:00
abstract::The response of folliculo-stellate (FS) cells of the anterior pituitary to estrogen has been studied in two strains of rat which differ in estrogen responsiveness. Fischer 344 (F344) rats are highly estrogen-responsive in comparison to Sprague-Dawley (S-D) rats. Ovariectomized adults were implanted with silastic capsu...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125064
更新日期:1988-11-01 00:00:00
abstract::Specific lesions of different brain structures known to contain or to be coursed by LHRH neurons have been carried out in intact cycling female rats in order to investigate the role played by central LHRH and neuronal systems in the regulation of ovarian and hypophyseal LHRH receptor (LHRH-R) levels, using the stable ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124196
更新日期:1985-10-01 00:00:00