The Neurosteroid Allopregnanolone Is Reduced in Prefrontal Cortex in Alzheimer’s Disease

BACKGROUND: Few data are currently available investigating neurosteroids (NS) in Alzheimer's disease (AD). The NS allopregnanolone may be decreased in serum and plasma in patients with AD, but it is unclear if allopregnanolone is also reduced in brain. Because a number of NS exhibit neuroprotective effects and impact cognitive performance in rodent models, these molecules may be relevant to the pathophysiology of neurodegenerative disorders. We therefore investigated prefrontal cortex (PFC) NS levels in AD. METHODS: Neurosteroid levels (allopregnanolone, pregnenolone, dehydroepiandrosterone [DHEA]) were determined in postmortem PFC in 14 male subjects with AD and 15 cognitively intact male control subjects by gas chromatography/mass spectrometry preceded by high-performance liquid chromatography purification. RESULTS: Subjects with AD exhibit significant reductions in allopregnanolone compared with cognitively intact control subjects (median levels = 2.50 ng/g vs. 5.59 ng/g, respectively; p = .02). Allopregnanolone levels are inversely correlated with neuropathological disease stage (Braak), r = -.49, p = .007. Median DHEA levels are elevated in subjects with AD (p = .01). CONCLUSIONS: Subjects with AD demonstrate significant reductions in PFC allopregnanolone levels, a finding that may be relevant to neuropathological disease stage severity. Neurosteroids may have utility as candidate biomarkers in AD.     

Catabolic effects and the influence on hormonal variables under treatment with gynodian-depot® or dehydroepiandrosterone (DHEA) oenanthate

53 patients from a mainly climacteric population were treated monthly with 200 mg dehydro-epiandrosterone (DHEA) oenanthate or with 1 ampoule Gynodian-Depot®. Pronounced adiposity was present in 15 of these cases. Hormonal variables were determined before the treatment and during the depot effect of the preparations in order to study the principle which supports the oestrogenic influence and any weight-reducing influence under administration of DHEA. The elimination of lowpolar oestrogens increased considerably in 4 out of 13 post-menopausal cases treated with DHEA. This effect is probably indirect and presupposes intact ovaries. The incorporation of exogenous DHEA into the excretion of 17-ketosteroids and of 17-ketogenic steroids, such as those of androsterone + aethiocholanolone, depends on the size of the initial pool inasmuch as it is higher in small initial pools than in saturated pools - the size of the pool being age-dependent.

An average weight loss of >1 kg/mth was observed under DHEA treatment in 7 out 15 adipose cases. In comparison to the other 8 adipose cases, these 7 were younger and therefore also displayed higher values for 17-ketosteroids and their individual fractions. These circumstances appeared to explain why the administration of DHEA resulted in higher levels of free plasma DHEA which, in contrast to the cases without loss of weight, also resulted in an increase of renal DHEA-sulphate clearance. It was concluded from the findings that this is the explanation for the catabolic effect of exogenous DHEA.

Post-menopausally increased FSH and LH fractions were markedly suppressed in about half of the determinations after Gynodian-Depot administration, the findings indicating that DHEA is probably involved in suppression of the LH fraction.     

Effect of Dehydroepiandrosterone on Avoidance Behavior of Adult Male Rats

We studied the effect of repeated intraperitoneal treatment with dehydroepiandrosterone in doses of 0.1 and 0.7 mg/kg on conditioned-response activity and behavior of adult male rats. The effect of dehydroepiandrosterone on learning was estimated in conditioned active and passive avoidance response paradigms. Chronic administration of dehydroepiandrosterone in low and high doses had no effect on retention of conditioned passive avoidance response in adult male rats 24 h after learning. However, chronic administration of dehydroepiandrosterone in low dose impaired acquisition of the conditioned active avoidance response. It should be emphasized that chronic administration of dehydroepiandrosterone in high dose did not modulate acquisition and retention of this reaction.     

Associations of alcohol, height, and reproductive factors with serum hormone concentrations in postmenopausal Japanese women

We measured serum levels of estradiol (E₂), sex hormone-binding globulin (SHBG), progesterone, and dehydroepiandrosterone sulfate (DHEAS) in 61 postmenopausal women drawn from female residents in a community in Japan to evaluate the relationships between these hormone levels and potential breast cancer risk factors. The information on reproductive history, body size, alcohol use, and physical activity was obtained by means of a self-administered questionnaire. There was a significant trend in increasing E₂ level with increasing height after taking account of age and body mass index (BMI) (p for trend = 0.04). BMI was inversely associated with SHBG level after controlling for age (p for trend = 0.01). Decreasing progesterone with increasing BMI was observed after controlling age and history of hysterectomy (P=0.05). Alcohol consumption was positively associated with E₂ level and there was a strong linear trend after controlling for age, height, and BMI (p for trend=0.001). Trend for increasing DHEAS with alcohol consumption was also statistically significant after controlling for age and history of hysterectomy (p for trend=0.01). Reproductive factors as well as physical activity were not related to any of the hormone levels.     

气相色谱/燃烧炉/同位素比值质谱方法对尿中去氢表雄酮及其代谢物的检测

目的测定服用去氢表雄酮制剂后人尿中去氢表雄酮及其代谢物的同位素比值(¹³C与¹²C含量比值的相对值，以δ表示)进行测定，以检测尿中类固醇的来源。方法采用固相萃取、酶解、薄层色谱等方法对尿样中内源性类固醇激素进行提取、酶解游离型、分离，再经气相色谱/燃烧炉/同位素比值质谱方法测定去氢表雄酮、其代谢物内源性类固醇激素、内源性类固醇参照物的同位素比值的相对值(δ值)。将被检测物与参照物δ值之比，与判别标准比较进行来源判定。结果服用去氢表雄酮制剂后人尿中内源性类固醇激素代谢物δ值比未使用去氢表雄酮制剂正常值降低，并提示有外源性类固醇摄入。结论本法可以检测尿中去氢表雄酮或其代谢物的来源。     

脱氢表雄酮增强双丁酰环磷酰苷促进细胞分化的作用及可能机制

目的　观察脱氢表雄酮 (DHEA)是否能增强cAMP的类似物双丁酰环磷酰苷 (DbcAMP)促进神经突起的形成和生长及可能的机制。方法　利用NG10 8 15细胞这一具有神经元形态和功能的细胞系 ,在药物处理后 ,倒置显微镜下观察突起的生长状况 ,并测定突起的长度和有突起的细胞数 ;明胶酶谱分析NG10 8 15细胞在药物处理后 ,上清的基质金属蛋白酶 (MMP)MMP 9和MMP 2的分泌和酶的活性的变化。结果　①DHEA和DbcAMP可抑制NG10 8 15细胞的增殖 ;②DHEA可增强DbcAMP促进NG10 8突起生长的作用。Db cAMP可以诱导NG10 8细胞突起的形成和生长 ,而DHEA收稿日期 :2 0 0 4-0 2 -0 3 ,修回日期 :2 0 0 4-0 4-19作者简介 :廖　红 ( 1965 -) ,女 ,副教授 ,博士 ,研究方向 :分子药理、神经药理 ,Tel:0 2 5 83 5 93 3 74;E mail:liaohong5 6@hotmail.com与DbcAMP同时作用 ,NG10 8 15细胞突起的长度明显增加 ,而且有突起的细胞数也明显增多 ,DHEA的剂量越高 ,这种促NG10 8 15细胞突起生长的作用越明显。③基质金属蛋白酶参与神经元的分化。DbcAMP能诱导MMP 9和MMP 2的分泌 ,与之相比 ,DHEA +DbcAMP使NG10 8 15细胞的MMP 9和MMP 2的分泌明显增多 ,且具有剂量依赖关系。结论　DHEA具有增强DbcAMP促进NG10 8 15细胞突起形成和生长的作用     

神经甾体的合成和代谢及其对神经系统作用

神经甾体是指存在于中枢和外周神经系统，不需依赖于内分泌腺体的甾体激素，包括孕烯醇酮、孕酮、别孕烯醇酮、脱氢表雄酮等，由胆固醇或其前体在相应酶的作用下在神经系统合成。神经甾体可以通过作用于GABAA受体、NMDA受体和σ受体发挥作用。它们对记忆、睡眠、惊厥、细胞兴奋性毒性等产生相应的作用，为某些疾病的治疗指明方向。     

Dopamine D1 receptor activation induces dehydroepiandrosterone sulfotransferase （SULT2A1） in HepG2 cells

Aim： Dopamine receptors are present in the nervous system and also widely distributed in the periphery. The aim of this study was to investigate the role of D1 subtype dopamine receptors （DRD1） in the regulation of dehydroepiandrosterone sulfotransferase （SULT2A1） in HepG2 cells. Methods： HepG2 cells were treated with DRD1 agonists with or without DRD1 antagonist for 9 d. DRD1 and SULT2A1 mRNA expression, protein expression, and SULT2A1 activity were detected using RT-PCR, Western blotting and HPLC, respectively. The level of cAMP was measured using a commercial kit. Results： All the 5 DR subtypes （DRD1-DRD1） were found to be expressed in HepG2 cells. Treatment of HepG2 cells with the specific DRD1 agonists SKF82958 （2.5 μmol/L） or SKF38393 （5 and 50 μmol/L） significantly increased the mRNA and protein expression of both DRD1 and SULT2A1, and increased SULT2A1 activity and cAMP levels. These effects were partially blocked by co-treatment with the specific DRD1 antagonist SCH23390 （2.5 μmol/L）. In addition, transfection of HepG2 cells with DRD1-specific siRNAs decreased DRD1 mRNA expression by 40%, which resulted in the reduction of SULT2A1 mRNA expression by 60%, protein expression by 40%, and enzyme activity by 20%. Conclusion： DRD1 activation upregulates DRD1 and SULT2A1 expression and SULT2A1 activity in HepG2 cells, suggesting that the DRD1 subtype may be involved in the metabolism of drugs and xenobiotics through regulating SULT2A1.