Are separable aromatase systems involved in hormonal regulation of the male brain

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Journal of Neurobiology; (USA)

DOI:https://doi.org/10.1002/neu.480210508· OSTI ID:6510870

Hutchison, J B; Schumacher, M; Steimer, T; Gahr, M ^[1]

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1. Institute of Animal Physiology, Babraham, Cambridge (England)

In vitro study of testosterone (T) metabolism shows that formation of estradiol-17 beta (E2) is regionally specific within the preoptic area (POA) of the male ring dove. The POA is known to be involved in the formation of E2 required for specific components of male sexual behavior. Two sub-areas of high aromatase activity, anterior (aPOA) and posterior preoptic (pPOA) areas, have been identified. Aromatase activity is higher in aPOA than in pPOA. The aromatase activity within the aPOA is also more sensitive to the inductive effects of low circulating T, derived from subcutaneous silastic implants, than the enzyme activity in pPOA. Kinetic analysis of preoptic fractions indicates that a similar high-affinity enzyme occurs in both areas (apparent Km less than 14 nM), but the Vmax of aPOA enzyme activity is higher than pPOA. Cells containing estrogen receptors (ER) are localized in areas of high aromatase activity. There is overlap between immunostained cells in the aPOA and in samples containing inducible aromatase activity measured in vitro. Within the aPOA there is a higher density of ER cells in the nucleus preopticus medialis. The pPOA area also contains ER, notably in the nucleus interstitialis, but at a lower density. We conclude that the hormonal regulation of the male preoptic-anterior hypothalamic region, which is a target for the behavioral action of T, involves at least two inducible aromatase systems with associated estrogen receptor cells.

• OSTI ID: 6510870
• Journal Information: Journal of Neurobiology; (USA), Journal Name: Journal of Neurobiology; (USA) Vol. 21:5; ISSN JNEUB; ISSN 0022-3034
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANDROGENS
ANDROSTANES
ANIMAL CELLS
ANIMALS
BEHAVIOR
BIRDS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
ENZYME ACTIVITY
ENZYMES
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOMERASES
ISOTOPE APPLICATIONS
KETONES
MEMBRANE PROTEINS
METABOLISM
NERVE CELLS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RECEPTORS
SOMATIC CELLS
STEROID HORMONES
STEROIDS
TESTOSTERONE
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES