Testosterone and Corticosterone in the Mesocorticolimbic System of Male Rats: Effects of Gonadectomy and Caloric Restriction
Autor: | Jordan E. Hamden, Anastasia M Korol, Daniel J. Tobiansky, Ryan J. Tomm, Kiran K. Soma, Chunqi Ma, Cecilia Jalabert |
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Rok vydání: | 2017 |
Předmět: |
0301 basic medicine
Male medicine.medical_specialty Neuroactive steroid 3-Hydroxysteroid Dehydrogenases Prefrontal Cortex Nerve Tissue Proteins Nucleus accumbens Weight Gain Gene Expression Regulation Enzymologic Nucleus Accumbens 03 medical and health sciences chemistry.chemical_compound Random Allocation 0302 clinical medicine Endocrinology Aromatase Corticosterone Internal medicine medicine Limbic System Animals Rats Long-Evans Testosterone Caloric Restriction biology Dopaminergic Neurons Ventral Tegmental Area Steroid 17-alpha-Hydroxylase Ventral tegmental area 030104 developmental biology medicine.anatomical_structure chemistry CYP17A1 biology.protein Orchiectomy 030217 neurology & neurosurgery Hormone |
Zdroj: | Endocrinology. 159(1) |
ISSN: | 1945-7170 |
Popis: | Steroid hormones can modulate motivated behaviors through the mesocorticolimbic system. Gonadectomy (GDX) is a common method to determine how steroids influence the mesocorticolimbic system, and caloric restriction (CR) is often used to invigorate motivated behaviors. A common assumption is that the effects of these manipulations on brain steroid levels reflects circulating steroid levels. We now know that the brain regulates local steroid levels in a region-specific manner; however, previous studies have low spatial resolution. Using ultrasensitive liquid chromatography tandem mass spectrometry, we examined steroids in microdissected regions of the mesocorticolimbic system (ventral tegmental area, nucleus accumbens, medial prefrontal cortex). We examined whether GDX or CR influences systemic and local steroids, particularly testosterone (T) and steroidogenic enzyme transcripts. Adult male rats underwent a GDX surgery and/or CR for either 2 or 6 weeks. Levels of T, the primary steroid of interest, were higher in all brain regions than in the blood, whereas corticosterone (CORT) was lower in the brain than in the blood. Importantly, GDX completely eliminated T in the blood and lowered T in the brain. Yet, T remained present in the brain, even 6 weeks after GDX. CR decreased both T and CORT in the blood and brain. Steroidogenic enzyme (Cyp17a1, 3β-hydroxysteroid dehydrogenase, aromatase) transcripts and androgen receptor transcripts were expressed in the mesocorticolimbic system and differentially affected by GDX and CR. Together, these results suggest that T is synthesized within the mesocorticolimbic system. These results provide a foundation for future studies examining how neurosteroids influence behaviors mediated by the mesocorticolimbic system. |
Databáze: | OpenAIRE |
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