Seasonal variations in the aromatase activity in H. fossilis estimated by a microassay were correlated with the sex steroids, vitellogenin in and ovarian weight during circannual reproductive cycle. In the female catfish, aromatase activity was detectable in the hypothalamus throughout the year whereas in ovary only during active vitellogenesis. In the catfish, hypothalamic aromatase levels inc...

Many chemicals in the aquatic environment are able to adversely affect in vitro brain and ovarian aromatase expression/activity. However, it remains to be determined if these substances elicit in vivo effect in fish. With the view to further understanding possible effects of endocrine disrupting chemicals (EDCs) on aromatase function, we first developed methods to measure brain and ovarian arom...

Prostaglandin E2 (PGE2) and cytokines, such as interleukin-6 (IL-6) or tumour necrosis factor a (TNFalpha) can regulate aromatase activity. In the present study we have compared their abilities to stimulate aromatase activity in fibroblasts derived from 'normal' breast adipose tissue proximal to a tumour or breast tumours. PGE2, TNFalpha and IL-6 plus its soluble receptor (IL-6sR) all increased...

The roles of estrogen and androgens in male social behavior are well studied, but little is known about how these hormones contribute to behavior in a social hierarchy. Here we test the role of aromatase, the enzyme that converts testosterone into estradiol, in mediating aggression and reproductive behavior in male Astatotilapia burtoni, an African cichlid fish that displays remarkable plastici...

Numerous studies show that 17β-estradiol (E2) protects against Alzheimer's disease (AD) induced neurodegeneration. The E2-synthesizing enzyme aromatase is expressed in healthy hippocampi, but although the hippocampus is severely affected in AD, little is known about the expression of hippocampal aromatase in AD. To better understand the role of hippocampal aromatase in AD, we studied its expres...

Endocrine disruptor chemicals are known to cause a range of abnormalities in sexual differentiation and reproduction. One mechanism underlying such effects may be via alteration of aromatase activity, which is responsible for estrogen production. A good screening system for identifying endocrine disruptors has long been desired. We have recently established a human ovarian granulosa-like tumor ...

Aromatase is a member of the cytochrome P450 superfamily that catalyzes the conversion of androgens (C(19)), namely testosterone and androstenedione, into oestrogens (C(18)), oestradiol, and oestrone, respectively. The enzyme is active in various tissues in both females and males, thus oestrogens are produced not only in gonads but also in extra-gonadal localizations such as brain, adipose tiss...

The estrogen synthesizing enzyme, P450 aromatase, plays a critical role in the regulation of vertebrate sexual behavior. Songbirds differ from other avian species in the distribution and expression of aromatase in the telencephalon. The highest concentration of aromatase in the songbird brain is found in the caudomedial neostriatum (NCM). This area surrounds the only nucleus of the neural song ...

BACKGROUND Aromatase deficiency is a rare, autosomal recessive disorder of which there are approximately twenty four case reports. The aromatase enzyme is crucial in the biosynthesis of oestrogens from androgens. The phenotype of aromatase deficiency therefore is the result of androgen excess and oestrogen deficiency in the absence of normal aromatase activity. We report the first case of aroma...