Steroid hormones brain

Garcia-Ovejero, D., Azcoitia, I., Doncarlos, L. L., Melcangi, R. C. Garcia-Segura, L. M. (2005). Glia-neuron crosstalk in the neuroprotective mechanisms of sex steroid hormones. Brain Res. Brain. Res. Rev. 48, 273-86. 

Baum LO, Strobel HW. 1997. Regulation of expression of cytochrome P-450 2D mRNA in rat brain with steroid hormones. Brain Res 765 67-73. 

Garcia-Ovejero D, Azcoitia I, Doncarlos LL, Melcangi RC, Garcia-Segura LM. 2005. GHa-neuron crosstalk in the neu-roprotective mechanisms of sex steroid hormones. Brain Res Brain Res Rev 48 273-286. 

Steroid Hormones and Neurosteroids. Steroids (qv) can affect neuroendocrine function, stress responses, and behavioral sexual dimorphism (78,79) (see Steroids). Mineralocorticoid, glucocorticoid, androgen, estrogen, and progesterone receptors are localized in the brain and spinal cord. In addition to genomic actions, the neurosteroid can act more acutely to modulate the actions of other receptors or ion channels (80). Pregnenolone [145-13-17, ( ) dehydroepiandosterone [53-43-0] C H2 02 (319) are excitatory neurosteroids found in rat brain, independent of adrenal... 

In the early 1930 s, when the prime research aim was the commercial synthesis of the sex hormones (whose structures had just been elucidated), the principal raw material available was cholesterol extracted from the spinal cord or brain of cattle or from sheep wool grease. This sterol (as its 3-acetate 5,6-dibromide) was subjected to a rather drastic chromic acid oxidation, which produced a variety of acidic, ketonic and hydroxylated products derived mainly by attack on the alkyl side-chain. The principal ketonic material, 3j -hydroxyandrost-5-en-17-one, was obtained in yields of only about 7% another useful ketone, 3 -hydroxypregn-5-en-20-one (pregnenolone) was obtained in much lower yield. The chief acidic product was 3j -hydroxy-androst-5-ene-17j -carboxylic acid. All three of these materials were then further converted by various chemical transformations into steroid hormones and synthetic analogs ... 

Ovarian hormones influence fluid intake by interaction with the brain renin-angiotensin system and it has been shown that gonadal steroids affect brain fluid-electrolyte balance by interactions with vasopressin. Both hyperos-molarity and increased intracranial pressure stimulate vasopressin release and intraperitoneal administration of vasopressin antagonists decrease brain volume. 

Some steroid hormones are converted in the brain to more active products that interact with receptors 847... 

During development, steroid-hormone receptors become evident in target neurons of the brain 854... 

Several criteria determine whether a steroid-hormone-binding site is a putative receptor. First, the steroid-hormone-binding site must be present in hormone-responsive tissues or brain regions, and absent from nonresponsive ones. Second, it should bind steroids that are either active agonists or effective antagonists of the hormone effect, and should not bind steroids that are inactive in either sense. 

Like steroid hormones, thyroid hormones interact with receptors to alter genomic activity and affect the synthesis of specific proteins during development [25-28], As with testosterone and progesterone, metabolic transformation of thyroxine (T4) is critical to its action [25-28]. Moreover, as with steroid hormones, thyroid hormones alter brain functions in adult life in ways that both resemble and differ from their action during development [25-28]. 

Brain delivery of steroid hormones is also of interest to medicinal chemists. Again, most data available on CDSs of steroids pertain to rates of oxidation of the dihydropyridine carrier, to blood and brain concentrations, and to pharmacological activities. The latter can then be taken as proof of efficient cerebral hydrolysis of the pyridinium metabolite. Thus, the dihydrotrigonelline carrier allowed good brain delivery of estradiol and some other estrogens [181][182],... 

Rat astrocytes and neurons express CYP17, synthesize DHEA from pregnenolone. Astrocytes metabolize DHEA to sex steroid hormones (Zwain and Yen, 1999). CYP17 expressed regionally in male and female avian brain (Matsunaga et al., 2001). 

Cytochrome P450 pathways in human brain cholesterol, steroid hormones, vitamin D, and bile... 

Kato, J., Hirata, S., Hagihara, K., Osada, T., Hirai, M., and Ikagami, J. (1992) Gene expression of steroid hormone receptors in brain and peripheral tissues relative to reproduction. Acta Histochem. Cytochem. 25,667-680. 

The hippocampus has innumerable afferent and efferent connections to other brain structures both within the limbic system and beyond. There are receptors for many different chemical signals ranging from the "classical neurotransmitters such as acetylcholine to steroid hormones and neurotrophic factors. Some of these receptors are located in the synapses that form the intrinsic hippocampal circuits and others are the targets of specific projection pathways from other brain areas. A comprehensive review of all neurotransmitter interactions relevant to function is not within the scope of this chapter. There are detailed reviews of modulation of neurochemical systems on place learning in the watermaze (McNamara and Skelton, 1993) or other limbic-system dependent tasks (Izquierdo and Medina, 1995) in animals. The effects of key neurochemical, other than NMDA channel-mediated, and environmental influences are discussed below. 

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