| Effect of steroid milieu on gonadotropin-releasing hormone-1 neuron firing pattern and luteinizing hormone levels in male mice. | |
| | |
MedLine Citation:
|
PMID: 16452459 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
GnRH neuronal function is regulated by gonadal hormone feedback. In males, testosterone can act directly or be converted to either dihydrotestosterone (DHT) or estradiol (E2). We examined central steroid feedback by recording firing of green fluorescent protein (GFP)-identified GnRH neurons in brain slices from male mice that were intact, castrated, or castrated and treated with implants containing DHT, E2, or E2 + DHT. Castration increased LH levels. DHT or E2 alone partially suppressed LH, whereas E2 + DHT reduced LH to intact levels. Despite the inhibitory actions on LH, the combination of E2 + DHT increased GnRH neuron activity relative to other treatments, reflected in mean firing rate, amplitude of peaks in firing rate, and area under the curve of firing rate vs. time. Cluster8 was used to identify peaks in firing activity that may be correlated with hormone release. Castration increased the frequency of peaks in firing rate. Treatment with DHT failed to reduce frequency of these peaks. In contrast, treatment with E2 reduced peak frequency to intact levels. The frequency of peaks in firing rate was intermediate in animals treated with E2 + DHT, perhaps suggesting the activating effects of this combination partially counteracts the inhibitory actions of E2. These data indicate that E2 mediates central negative feedback in males primarily by affecting the pattern of GnRH neuron activity, and that androgens combined with estrogens have a central activating effect on GnRH neurons. The negative feedback induced by E2 + DHT to restore LH to intact levels may mask an excitatory central effect of this combination. |
| | |
Authors:
|
Justyna Pielecka; Suzanne M Moenter |
Related Documents
:
|
9550119 - Gonadotropin pulsations across development. 8275929 - Corticosterone in vivo increases pituitary follicle-stimulating hormone (fsh)-beta mess... 21872309 - Boar seminal plasma or hen's egg yolk decrease the in-vitro chemotactic and phagocytoti... 15492969 - The hypothalamic-pituitary axis in men and women with chronic kidney disease. 6305079 - Comparison of oestrogen and gnrh agonist analogue-induced inhibition of the pituitary-t... 15305569 - Sex and reproductive status related brain content of mammalian and chicken-ii gnrhs in ... 9550119 - Gonadotropin pulsations across development. 2856699 - Patients with essential hypertension have an exaggerated natriuretic response to the do... 758729 - The concentrations of copper and zinc in human milk. a longitudinal study. |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2006-02-01 |
Journal Detail:
|
Title: Biology of reproduction Volume: 74 ISSN: 0006-3363 ISO Abbreviation: Biol. Reprod. Publication Date: 2006 May |
Date Detail:
|
Created Date: 2006-04-21 Completed Date: 2006-08-09 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0207224 Medline TA: Biol Reprod Country: United States |
Other Details:
|
Languages: eng Pagination: 931-7 Citation Subset: IM |
Affiliation:
|
Department of Internal Medicine, University of Virginia, Charlottesville, Virginia 22908, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Dihydrotestosterone / administration & dosage Gonadal Steroid Hormones / physiology* Gonadotropin-Releasing Hormone / secretion* Hypothalamo-Hypophyseal System / secretion* Luteinizing Hormone / metabolism* Male Mice Neurons / secretion* |
| Grant Support | |
ID/Acronym/Agency:
|
U54HD28934/HD/NICHD NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Gonadal Steroid Hormones; 33515-09-2/Gonadotropin-Releasing Hormone; 521-18-6/Dihydrotestosterone; 9002-67-9/Luteinizing Hormone |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Multiplicity of progesterone's actions and receptors in the mammalian ovary.
Next Document: Developmental effects of sublethal mitochondrial injury in mouse oocytes.