DHEA AND Sato

Androgens, such as testosterone, play important roles in regulation of diverse physiological process of target tissues. Recently, we reported that steroidogenic enzymes exist in skeletal muscle and regulate local production of testosterone in response to exercise. Testosterone is transformed into a bioactive androgen metabolite, dihydrotestosterone (DHT) by 5alpha-reductase. However, it is unclear whether exercise stimulates local bioactive androgen metabolism in the skeletal muscle in both sexes. In the present study, we examined sex differences in the levels of dehydroepiandrosterone (DHEA), free testosterone, DHT, and steroidogenesis-related enzymes 5alpha-reductase and androgen receptor (AR) in rat's skeletal muscle before and after a single bout of exercise...

AIM: Addition of dehydroepiandrosterone (DHEA) to a cultured skeletal muscle locally synthesizes 5alpha-dihydrotestosterone (DHT). It induced activation of glucose metabolism-related signalling pathway via protein kinase B (Akt) and protein kinase C zeta/lambda (PKC zeta/lambda)-glucose transporter-4 (GLUT4) proteins. However, such an effect of DHEA in vivo remains unclear. METHODS: Using streptozotocin (STZ)-induced rats with type 1 diabetes mellitus, we tested the hypothesis that a single bout of DHEA injection in the rats improves hyperglycaemia and muscle GLUT4-regulated signalling pathway...

BACKGROUND: The associations of endogenous estrogen with lipid profiles and insulin resistance were conflicting in both men and women. We determined the associations of serum estradiol level and free estradiol index (FEI) with lipid profiles and insulin resistance in aged Japanese men and women. METHODS: One hundred seventy-four men and 208 postmenopausal women aged from 50 to 85 y were included in this study. Lipid profiles, fasting glucose and insulin as well as estradiol, testosterone, dehydroepiandrosterone-sulfate (DHEA-S) and sex hormone-binding globulin (SHBG) in serum were measured...

AZT (3'-azido-3'-deoxythymidine; zidovudine), which is used for the prevention of mother-to-child transmission of HIV-1, is transplacentally transferred to the fetus across the blood-placenta barrier, which is composed of syncytiotrophoblasts. We recently showed that apical uptake of AZT by syncytiotrophoblasts is mediated by saturable transport system(s) in the TR-TBT 18d-1 cell line, and the cellular accumulation of AZT was increased in the presence of dehydroepiandrosterone sulfate (DHEAS). Here, we aimed to clarify the mechanism of this effect of DHEAS...

Circulating dehydroepiandrosterone (DHEA) is converted to testosterone or estrogen in the target tissues. Recently, we demonstrated that skeletal muscles are capable of locally synthesizing circulating DHEA to testosterone and estrogen. Furthermore, testosterone is converted to 5alpha-dihydrotestosterone (DHT) by 5alpha-reductase and exerts biophysiological actions through binding to androgen receptors. However, it remains unclear whether skeletal muscle can synthesize DHT from testosterone and/or DHEA and whether these hormones affect glucose metabolism-related signaling pathway in skeletal muscles...

The progression of the nuclear maturation of oocytes is a useful marker for the estimation of the subsequent developmental competence of oocytes. In this study, we examined the effect of energy substrates in an in vitro maturation medium on the progression of the nuclear maturation of oocytes. In experiment 1, the supplementation of the maturation medium with 0, 5 and 10 mM of glucose lead to increase in the total cell number of the blastocysts. In experiments 2 and 3, the maturation phase was divided into two stages (germinal vesicle (GV) stage: 0-20 h and nuclear maturation stage: 20-44 h), and the effects of glucose or pyruvate added at each stage on the kinetics of nuclear maturation were examined...

Cytosolic reducing cofactors, such as NADPH and NADH, are thought to regulate vascular smooth muscle ion channel activity and vascular tone. In this study, the effects of pentose phosphate pathway (PPP) inhibitors, 6-aminonicotinamide (6-AN), epiandrosterone (EPI), and dehydroepiandrosterone (DHEA), on vascular tone were studied in isolated perfused lungs and pulmonary artery (PA) and aortic rings from rats. In addition, effects of 6-AN on voltage-gated K(+) (K(v)) current in PA smooth muscle cells (SMCs) were also examined...

Dehydroepiandrosterone sulfotransferase (DHEA-ST) catalyzes the conversion of dehydroepiandrosterone (DHEA) to dehydroepiandrosterone sulfate (DHEA-S) in the adrenals. Both DHEA and DHEA-S are quantitatively the most important corticosteroids in human. In this study, DHEA-ST was immunolocalized in normal (5 cases) and neoplastic human adrenal glands (33 cases), using a specific IgG fraction raised against the enzyme. DHEA-ST was present in almost all the zona reticularis cells and some cortical cells demonstrating lipid depletion in the zona fasciculata but not in the zona glomerulosa of the normal adrenal...

We have studied 37 cases of ovarian epithelial tumors in post-menopausal women, histopathologically and endocrinologically. The normal values for androstenedione, estrone, estradiol and progesterone in healthy post-menopausal women were less than 83 ng/dl, 75 pg/ml, 30 pg/ml and 0.6 ng/ml, respectively. The numbers of cases, the serum values for which were higher than normal, were 9 of 16 (androstenedione), 9 of 16 (estrone), 22 of 29 (estradiol) and 14 of 20 (progesterone). The serum levels of these 4 sex hormones in cases with ovarian stromal condensation (stromal cell hyperplasia) were higher than normal in 8 of 11 (androstenedione), 8 of 11 (estrone), 17 of 19 (estradiol) and 9 of 12 (progesterone), whereas those in cases with no stromal condensation were elevated in 1 of 5, 1 of 5, 5 of 8 and 5 of 7, respectively...

A new method for determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) from 1 ml serum by reverse phase thin-layer chromatography (TLC) is described. The method comprises an isolation step of sulfated steroids by means of octadecylsilane-bonded (C18) reverse phase column chromatography, a solvolysis step for desulfation of sulfated steroids, and a C18 TLC step for measurement on a photodensitometer. This method is much simpler and more rapid than the methods previously reported, since neither a radioisotope is needed, nor any steps of saponification, derivatization, tedious scraping from a TLC plate, and time-consuming conventional column chromatography are not required...

The effects of concomitant treatment with dehydroepiandrosterone, an inhibitor of glucose-6-phosphate dehydrogenase (G6PD), diaminopropane (DAP), an inhibitor of ornithine decarboxylase or the microsomal drug detoxifying enzyme inducer butylated hydroxyanisole (BHA) during the induction phase of rat liver nodular lesion development were investigated. Clear reductions in both number and size of foci and nodules as assayed quantitatively with the aid of marker enzymes G6PD, glutathione S-transferase P form or gamma-glutamyl transpeptidase were established for treatment with either DHEA or BHA...

Following initial treatment of F344 rats with dihydroxy-di-n-propylnitrosamine, exposure to dehydroepiandrosterone (DHEA) administered in the diet at a concentration of 0.6% brought about significant decrease in weight gain, independent of food consumption, and inhibited the development of thyroid tumors and hepatocyte-altered enzyme foci. In addition to inducing a diffuse increase in glucose-6-phosphatase dehydrogenase (G6PD) and gammaglutamyl transpeptidase in the liver. DHEA treatment was associated with development of small numbers of basophilic hepatocellular foci which differed markedly in enzyme phenotype from the clear cell (glycogen storing) lesions predominating in the carcinogen-treated animals maintained on basal diet...

A new gas-liquid chromatographic (GLC) determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) for a biochemical diagnosis of recessive X-linked ichthyosis (RXLI) is described. Although the GLC method for determination of CS is known to be more sensitive than the thin layer chromatographic (TLC) method, the former method has not been widely employed because of its complicated pre-purification steps. The present method allows us to measure the serum levels of CS and DHEAS without tedious purification steps such as multiple conventional column chromatography and preoperative thin layer chromatography...